livescience--2020-08-26--Half of Antarctic ice shelves could collapse in a flash, thanks to warming

Antarctic ice shelves can disappear astonishingly fast — sometimes in minutes or hours — as meltwater surges through cracks in their surface .
And as the atmosphere warms , this phenomenon may become more commonplace ; at least half of the ice shelves on the continent are vulnerable to this process , a new study suggests .
These floating ice sheets ring 's glaciers and prevent them from sliding into the ocean .
Without these icy barriers , glaciers would flow more quickly into the water , causing the continent to shrink and accelerating sea level rise .
The new @ @ @ @ @ @ @ ) in the journal , suggests that about 50 % to 70 % of ice shelves that hold Antarctic glaciers in place could become weak and potentially collapse with surges of meltwater .
Related : 10 signs that Earth 's climate is off the rails '' What we find is that the amount of melting is important , but where the melting happens is also important , '' said lead author Ching-Yao Lai , a postdoctoral researcher in the Department of Marine Geology & Geophysics at Columbia University 's Lamont-Doherty Earth Observatory in @ @ @ @ @ @ @ ice shelves are most likely to crumble , but not when this dissolution is most likely to occur .
`` The time frame over which this process could happen is the biggest question , '' Christine Dow , the Canada Research Chair in Glacier Hydrology and Ice Dynamics at the University of Waterloo , who was not involved in the study , told Live Science in an email .
Some ice shelves float on open water and do not slow glaciers ' slide into the sea , because there 's no land mass @ @ @ @ @ @ @ ice shelves confined to bays and gulfs create a physical barrier that the slow-moving glaciers butt up against .
Lai and her colleagues focused on these so-called buttressing ice shelves .
The buttressing shelves accumulate cracks on their surfaces as glaciers push against them from behind , and cracks also appear as the shelf pushes against the curvature of the shoreline .
In addition , the ice shelves stretch out as they flow across the ocean water , due to their velocity , Lai told Live Science .
`` Usually near the front @ @ @ @ @ @ @ the fastest and this kind of breaking occurs , '' she said .
When warm atmospheric conditions cause the surface of an ice shelf to melt , meltwater can pool in these cracks and cause `` hydrofracturing '' — a process in which the excess water puts pressure on the ice , deepening the cracks and sometimes triggering a complete collapse of the shelf .
The melt water `` can punch through the ice to the ocean in a matter of minutes to hours , as long as there 's enough water available @ @ @ @ @ @ @ keep up the pressure , '' Dow said .
`` The crack in the ice then fills up with ocean water , '' and the shelf may begin to break apart .
Scientists theorize that this is what happened to an ice shelf known as Larsen B , which lost 1,255 square miles ( 3,250 square kilometers ) of ice over the course of a few weeks in 2002 , according to The National Snow and Ice Data Center .
For context , that area of ice is larger than the state of @ @ @ @ @ @ @ ice shelves are vulnerable to collapse , Lai and her colleagues developed a machine learning model — an algorithm that can be trained to recognize visual features based on past images it has analyzed .
The authors trained their model to recognize surface fractures in the ice using satellite images of two ice shelves , named Larsen C and George VI , in the northwest region of Antarctica , and then applied the model to a .
With their map of ice cracks in hand , the researchers then determined which fractures in @ @ @ @ @ @ @ prone to hydrofracture , given the pressures exerted on them from surrounding land masses and their movement over the water .
Researchers have used this analysis at specific ice shelves before , but `` this is the first time it has been applied to the Antarctic as a whole , '' Dow noted .
The next big question is `` how does this hydrofracture process contribute to the sea level rise ? ''
Lai said .
To find out , the team will need to pair their model of ice cracks with climate @ @ @ @ @ @ @ flows over the bedrock of Antarctica ; this ice flows downslope into the ocean `` just like rivers flowing downhill , '' she said .
In the future , this type of research will help the authors determine how fast and how much sea level rise could change due to cracking ice sheets , given rising atmospheric temperatures , Lai noted .
As of now , `` estimating time scales on which these ice shelves might break up due to surface melting and hydrofracture is beyond the scope of their study , '' @ @ @ @ @ @ @ the Cooperative Institute for Research in Environmental Sciences ( CIRES ) at the University of Colorado Boulder , who was not involved in the study , told Live Science in an email .
Though the researchers do n't have a time frame yet , some scientists predict that may drive massive hydrofracturing events within a matter of decades , according to a 2015 report in the journal .
`` Also , Antarctic ice shelves are currently losing most [ of their ] mass due to basal melting , '' or melting on the @ @ @ @ @ @ @ in response to warming ocean temperatures , '' Banwell added .
`` It would be interesting to see which ice shelves are most vulnerable due to all three processes , '' meaning basal melt , surface melt and hydrofracture , combined .
Basal melting could make ice shelves more prone to hydrofracture , as the shelves become thin and stretch more easily the more they melt , Lai added .

An image shows cracks on the surface of the Larsen b ice shelf, which covers waters off the shore of the Antarctic peninsula.
Antarctic ice shelves can disappear astonishingly fast — sometimes in minutes or hours — as meltwater surges through cracks in their surface. And as the atmosphere warms, this phenomenon may become more commonplace; at least half of the ice shelves on the continent are vulnerable to this process, a new study suggests.
These floating ice sheets ring Antarctica 's glaciers and prevent them from sliding into the ocean. Without these icy barriers, glaciers would flow more quickly into the water, causing the continent to shrink and accelerating sea level rise.
The new study, published today (Aug. 26) in the journal Nature , suggests that about 50% to 70% of ice shelves that hold Antarctic glaciers in place could become weak and potentially collapse with surges of meltwater.
Related: 10 signs that Earth's climate is off the rails
"What we find is that the amount of melting is important, but where the melting happens is also important," said lead author Ching-Yao Lai, a postdoctoral researcher in the Department of Marine Geology & Geophysics at Columbia University's Lamont-Doherty Earth Observatory in New York. The research highlights which ice shelves are most likely to crumble, but not when this dissolution is most likely to occur.
"The time frame over which this process could happen is the biggest question," Christine Dow, the Canada Research Chair in Glacier Hydrology and Ice Dynamics at the University of Waterloo, who was not involved in the study, told Live Science in an email.
Cracks in the ice
Some ice shelves float on open water and do not slow glaciers' slide into the sea, because there's no land mass for them to brace against. But ice shelves confined to bays and gulfs create a physical barrier that the slow-moving glaciers butt up against. Lai and her colleagues focused on these so-called buttressing ice shelves.
The buttressing shelves accumulate cracks on their surfaces as glaciers push against them from behind, and cracks also appear as the shelf pushes against the curvature of the shoreline. In addition, the ice shelves stretch out as they flow across the ocean water, due to their velocity, Lai told Live Science. "Usually near the front of ice shelves, it gets stretched the fastest and this kind of breaking occurs," she said.
When warm atmospheric conditions cause the surface of an ice shelf to melt, meltwater can pool in these cracks and cause "hydrofracturing" — a process in which the excess water puts pressure on the ice, deepening the cracks and sometimes triggering a complete collapse of the shelf.
The melt water "can punch through the ice to the ocean in a matter of minutes to hours, as long as there's enough water available to keep on filling the crevasse and keep up the pressure," Dow said. "The crack in the ice then fills up with ocean water," and the shelf may begin to break apart. Scientists theorize that this is what happened to an ice shelf known as Larsen B, which lost 1,255 square miles (3,250 square kilometers) of ice over the course of a few weeks in 2002, according to The National Snow and Ice Data Center . For context, that area of ice is larger than the state of Rhode Island.
Related: Photographic proof of climate change: Time-lapse images of retreating glaciers
To determine which buttressing ice shelves are vulnerable to collapse, Lai and her colleagues developed a machine learning model — an algorithm that can be trained to recognize visual features based on past images it has analyzed. The authors trained their model to recognize surface fractures in the ice using satellite images of two ice shelves, named Larsen C and George VI, in the northwest region of Antarctica, and then applied the model to a complete map of Antarctica .
With their map of ice cracks in hand, the researchers then determined which fractures in Antarctica's many ice shelves would be prone to hydrofracture, given the pressures exerted on them from surrounding land masses and their movement over the water. Researchers have used this analysis at specific ice shelves before, but "this is the first time it has been applied to the Antarctic as a whole," Dow noted.
The next big question is "how does this hydrofracture process contribute to the sea level rise?" Lai said. To find out, the team will need to pair their model of ice cracks with climate predictions and a model of how ice flows over the bedrock of Antarctica; this ice flows downslope into the ocean "just like rivers flowing downhill," she said.
In the future, this type of research will help the authors determine how fast and how much sea level rise could change due to cracking ice sheets, given rising atmospheric temperatures, Lai noted. As of now, "estimating time scales on which these ice shelves might break up due to surface melting and hydrofracture is beyond the scope of their study," Alison Banwell, a research scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder, who was not involved in the study, told Live Science in an email.
Though the researchers don't have a time frame yet, some scientists predict that climate change may drive massive hydrofracturing events within a matter of decades, according to a 2015 report in the journal Earth and Planetary Science Letters .
"Also, Antarctic ice shelves are currently losing most [of their] mass due to basal melting," or melting on the underside of the ice sheet, "in response to warming ocean temperatures," Banwell added. "It would be interesting to see which ice shelves are most vulnerable due to all three processes," meaning basal melt, surface melt and hydrofracture, combined. Basal melting could make ice shelves more prone to hydrofracture, as the shelves become thin and stretch more easily the more they melt, Lai added.
Originally published on Live Science.


livescience--2020-08-26--Earth's core is a billion years old

Earth's core is a billion years old

The solid inner core of Earth is a mere billion years old , new research finds .
Modern is like a layer cake , with a solid outer crust , a hot , viscous mantle , a liquid outer core and a solid inner core .
That solid inner core is growing slowly as the liquid in the core cools and crystallizes .
This process helps power the churning motion of the liquid outer core , which in turn creates the magnetic field that surrounds Earth and helps protect the planet from harmful cosmic radiation .
In other words , @ @ @ @ @ @ @ But not much is known about the history of this 1,500-mile-wide ( 2,442 kilometers ) iron ball .
Estimates of its age have ranged from half a billion years to more than 4 billion years , almost as old as 4.5-billion-year-old Earth itself .
Now , researchers have squeezed a miniscule piece of iron between two diamonds and blasted it with lasers to arrive at a new estimate of 1 billion to 1.3 billion years old — a date range that coincides with a measurable strengthening of the that happened around the same @ @ @ @ @ @ @ our in that it has a magnetic field , and that it 's habitable , '' study author Jung-Fu Lin , a geoscientist at the University of Texas at Austin , told Live Science .
`` Eventually our results could be used to think about why other planets in our solar system do n't have magnetic fields . ''
Earth 's magnetic field is powered by what scientists call the `` geodynamo . ''
That 's the movement of the iron-rich outer core , which turns the planet into a giant , if @ @ @ @ @ @ @ is responsible for Earth 's and South Pole and the invisible shield of magnetism that deflects and traps charged particles flowing from the sun .
These particles would otherwise slowly strip Earth of its atmosphere .
Part of the movement of the inner core is powered by heat , known as its thermal energy source .
As Earth 's core gradually cools , it crystallizes from the inside out .
This crystallization process releases energy that can further power the movement of the still-liquid outer core .
This energy release from crystallization is @ @ @ @ @ @ @ geodynamo , Lin said .
Lin and his team wanted to use experimental evidence to pin down the energy from each of these sources .
Knowing the amount of energy would allow them to estimate the age of the inner core .
To do this , the researchers recreated the conditions of the core on a tiny scale .
They heated a piece of iron a mere 6 microns thick ( about the same as the length of a red blood cell ) to temperatures up to 4,940 degrees Fahrenheit ( 2,727 degrees @ @ @ @ @ @ @ between two diamonds to match the extreme pressures at Earth 's core .
They then measured the conductivity of the iron under these conditions .
This conductivity measurement allowed the researchers to calculate the thermal cooling of the core that is available to power the geodynamo .
They found that the geodynamo drew on about 10 terawatts of energy from the cooling core — just over a fifth of the amount of heat the Earth dissipates into space from its surface ( 46 terawatts , ) .
One they calculated the amount of @ @ @ @ @ @ @ the age of the Earth 's inner core , Lin said .
Knowing the rate of energy loss allowed the researchers to calculate how long it would take to get a solid mass the size of today ’ s core from a blob of molten iron .
The 1 billion to 1.3 billion year result suggests that Earth 's core is `` actually relatively young , '' Lin said .
This estimate is n't as young as some estimates , such as one published in 2016 in the journal that used similar methods @ @ @ @ @ @ @ 700 million years old .
Lin said the new experiment used more reliable ways of handling the pressures and temperatures generated on the core , making that younger estimate unlikely .
Ancient magnetic rocks revealed that the magnetic field suddenly strengthened between 1 billion and 1.5 billion years ago , a 2015 study in the journal found .
The new age lines up nicely with that evidence , as the crystallization of the inner core would have provided a `` boost '' to the magnetic field , Lin said .
There are still @ @ @ @ @ @ @ in the core , Lin said .
Unlike the sample they tested , the core is n't just iron — it also contains lighter elements such as , , , silicon and sulfur .
But the proportions of these light elements are unknown , making it difficult to know how they change the conductivity of the inner core .
That 's what Lin and his team are working on now .
`` We are trying to understand how the existence of those light elements would actually affect the thermal transport properties of iron @ @ @ @ @ @ @ , '' Lin said .
The researchers reported their findings Aug. 13 in the journal .

A schematic of Earth's hot inner layers. New research finds that the uppermost layer of the crust is partially melted.
The solid inner core of Earth is a mere billion years old, new research finds.
Modern Earth is like a layer cake, with a solid outer crust, a hot, viscous mantle, a liquid outer core and a solid inner core. That solid inner core is growing slowly as the liquid iron in the core cools and crystallizes. This process helps power the churning motion of the liquid outer core, which in turn creates the magnetic field that surrounds Earth and helps protect the planet from harmful cosmic radiation.
In other words, the inner core is pretty important.
But not much is known about the history of this 1,500-mile-wide (2,442 kilometers) iron ball. Estimates of its age have ranged from half a billion years to more than 4 billion years, almost as old as 4.5-billion-year-old Earth itself. Now, researchers have squeezed a miniscule piece of iron between two diamonds and blasted it with lasers to arrive at a new estimate of 1 billion to 1.3 billion years old — a date range that coincides with a measurable strengthening of the Earth's magnetic field that happened around the same time.
Related: 10 ways Earth revealed its weirdness
"Earth is unique in our solar system in that it has a magnetic field, and that it's habitable," study author Jung-Fu Lin, a geoscientist at the University of Texas at Austin, told Live Science. "Eventually our results could be used to think about why other planets in our solar system don't have magnetic fields."
The geodynamo
Earth's magnetic field is powered by what scientists call the "geodynamo." That's the movement of the iron-rich outer core, which turns the planet into a giant, if somewhat messy, magnet. The geodynamo is responsible for Earth's North Pole and South Pole and the invisible shield of magnetism that deflects and traps charged particles flowing from the sun. These particles would otherwise slowly strip Earth of its atmosphere.
Part of the movement of the inner core is powered by heat, known as its thermal energy source. As Earth's core gradually cools, it crystallizes from the inside out. This crystallization process releases energy that can further power the movement of the still-liquid outer core. This energy release from crystallization is called the compositional energy source of the geodynamo, Lin said.
Lin and his team wanted to use experimental evidence to pin down the energy from each of these sources. Knowing the amount of energy would allow them to estimate the age of the inner core.
To do this, the researchers recreated the conditions of the core on a tiny scale. They heated a piece of iron a mere 6 microns thick (about the same as the length of a red blood cell) to temperatures up to 4,940 degrees Fahrenheit (2,727 degrees Celsius), and squeezed the sample between two diamonds to match the extreme pressures at Earth's core. They then measured the conductivity of the iron under these conditions.
A young core
This conductivity measurement allowed the researchers to calculate the thermal cooling of the core that is available to power the geodynamo. They found that the geodynamo drew on about 10 terawatts of energy from the cooling core — just over a fifth of the amount of heat the Earth dissipates into space from its surface (46 terawatts, Live Science previously reported ).
One they calculated the amount of energy loss, the researchers could calculate the age of the Earth's inner core, Lin said. Knowing the rate of energy loss allowed the researchers to calculate how long it would take to get a solid mass the size of today’s core from a blob of molten iron.
The 1 billion to 1.3 billion year result suggests that Earth's core is "actually relatively young," Lin said.
This estimate isn't as young as some estimates, such as one published in 2016 in the journal Nature that used similar methods but found the core was a mere 700 million years old. Lin said the new experiment used more reliable ways of handling the pressures and temperatures generated on the core, making that younger estimate unlikely.
Ancient magnetic rocks revealed that the magnetic field suddenly strengthened between 1 billion and 1.5 billion years ago, a 2015 study in the journal Nature found. The new age lines up nicely with that evidence, as the crystallization of the inner core would have provided a "boost" to the magnetic field, Lin said.
There are still questions about the way heat moves around in the core, Lin said. Unlike the sample they tested, the core isn't just iron — it also contains lighter elements such as carbon , hydrogen , oxygen , silicon and sulfur. But the proportions of these light elements are unknown, making it difficult to know how they change the conductivity of the inner core. That's what Lin and his team are working on now.
"We are trying to understand how the existence of those light elements would actually affect the thermal transport properties of iron at such high-pressure, high temperature conditions," Lin said.
The researchers reported their findings Aug. 13 in the journal Physical Review Letters .
Originally published in Live Science.


livescience--2020-08-26--Scientists discover the fastest-melting spot in East Antarctica

Researchers have discovered a deep underwater trough in that could spell doom for one of the continent 's vulnerable ice shelves .
Located hundreds of feet below the Shirase Glacier in East Antarctica , the trough appears to be funneling warm ocean water directly against the base of the ice shelf ( known as the Shirase Glacier Tongue ) , which juts out into the nearby bay like a frosty peninsula .
This pipeline of warm water is causing the tongue to melt from the bottom up at an alarming rate ; according to a new study published online Monday @ @ @ @ @ @ @ , the base of the Shirase Glacier Tongue is losing 22 to 52 feet of ice per year ( 7 to 16 meters ) –- potentially making it the fastest-melting region in East Antarctica .
`` This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf , which was thought to be experiencing the highest melting rate in East Antarctica , at a rate of 32 to 36 feet per year ( 10 to 11 meters per year ) , '' study author Daisuke Hirano , an @ @ @ @ @ @ @ of Low Temperature Science in Japan , .
The Shirase Glacier is part of the Antarctic ice sheet — a vast , frozen reservoir that contains more than 60 % of the world 's freshwater , according to the United Nations University , a research arm of the United Nations based in Tokyo .
Climate change is causing the ice sheet to melt at an ever-quickening pace , today than it was in 1992 and pouring more than 500 billion tons ( 453 billion metric tons ) of water into the sea every @ @ @ @ @ @ @ melts , it could raise global sea levels by 200 feet ( 60 m ) — but even a rise of 2 feet ( 60 centimeters ) could put hundreds of millions of people at risk of losing their homes ( or their lives ) to flooding , UN research has shown .
Still , the melt rates for many regions of Antarctica remain poorly studied , as thick sea ice can prevent research vessels from getting close enough to make needed observations .
That was the case for East Antarctica 's Shirase @ @ @ @ @ @ @ in late 2016 finally opened a path to the glacier .
In early 2017 , scientists aboard a Japanese research vessel sailed close enough to the Shirase Glacier Tongue to analyze 31 different points around the ice shelf , measuring the temperature , salinity and levels of the surrounding water .
From these variables , the team estimated how much melted freshwater had mixed in with the salty sea water , and where the warmest currents flowed .
Radar measurements helped them better map the area 's undersea geography .
The study revealed @ @ @ @ @ @ @ ocean water rushing along a previously unknown trough , hundreds of feet below the Shirase Glacier Tongue .
That warm water collides with the glacier 's edge and ricochets upward , strafing against the bottom of the ice tongue before u-turning back toward the sea again — taking loads of melted ice with it , the team found .
While the fate of a single ice shelf is n't enough to drastically change the outlook for future sea-level rise , understanding how ocean currents interact with little-studied parts of the Antarctic ice sheet @ @ @ @ @ @ @ quickly the continent could succumb to climate change .
`` We plan to incorporate this and future data into our computer models , which will help us develop more accurate predictions of sea level fluctuations and climate change , '' Hirano said .

Researchers have discovered a deep underwater trough in Antarctica that could spell doom for one of the continent's vulnerable ice shelves.
Located hundreds of feet below the Shirase Glacier in East Antarctica, the trough appears to be funneling warm ocean water directly against the base of the glacier's ice shelf (known as the Shirase Glacier Tongue), which juts out into the nearby bay like a frosty peninsula. This pipeline of warm water is causing the tongue to melt from the bottom up at an alarming rate; according to a new study published online Monday (Aug. 24) in the journal Nature Communications , the base of the Shirase Glacier Tongue is losing 22 to 52 feet of ice per year (7 to 16 meters) –- potentially making it the fastest-melting region in East Antarctica.
"This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf, which was thought to be experiencing the highest melting rate in East Antarctica, at a rate of 32 to 36 feet per year (10 to 11 meters per year)," study author Daisuke Hirano, an assistant professor at Hokkaido University's Institute of Low Temperature Science in Japan, said in a statement .
The Shirase Glacier is part of the Antarctic ice sheet — a vast, frozen reservoir that contains more than 60% of the world's freshwater, according to the United Nations University, a research arm of the United Nations based in Tokyo . Climate change is causing the ice sheet to melt at an ever-quickening pace, melting six times faster today than it was in 1992 and pouring more than 500 billion tons (453 billion metric tons) of water into the sea every year.
Warm sea water hundreds of feet below the ocean's surface swoops along an undersea trough, melting the base of the Shirase Glacier Tongue and flushing the meltwater back out to sea. (Image credit: Daisuke Hirano et al., Nature Communications)
If the entire ice sheet melts, it could raise global sea levels by 200 feet (60 m) — but even a rise of 2 feet (60 centimeters) could put hundreds of millions of people at risk of losing their homes (or their lives) to flooding, UN research has shown.
Still, the melt rates for many regions of Antarctica remain poorly studied, as thick sea ice can prevent research vessels from getting close enough to make needed observations. That was the case for East Antarctica's Shirase Glacier, until a huge ice-calving event in late 2016 finally opened a path to the glacier.
In early 2017, scientists aboard a Japanese research vessel sailed close enough to the Shirase Glacier Tongue to analyze 31 different points around the ice shelf, measuring the temperature, salinity and oxygen levels of the surrounding water. From these variables, the team estimated how much melted freshwater had mixed in with the salty sea water, and where the warmest currents flowed. Radar measurements helped them better map the area's undersea geography.
The study revealed an "atypical hotspot" of warm ocean water rushing along a previously unknown trough, hundreds of feet below the Shirase Glacier Tongue. That warm water collides with the glacier's edge and ricochets upward, strafing against the bottom of the ice tongue before u-turning back toward the sea again — taking loads of melted ice with it, the team found.
While the fate of a single ice shelf isn't enough to drastically change the outlook for future sea-level rise, understanding how ocean currents interact with little-studied parts of the Antarctic ice sheet is a crucial part of predicting how quickly the continent could succumb to climate change.
"We plan to incorporate this and future data into our computer models, which will help us develop more accurate predictions of sea level fluctuations and climate change," Hirano said.
Originally published on Live Science.


livescience--2020-08-26--Could the universe collapse into a singularity? New study explains how.

Has the universe been around forever ?
If so , perhaps it 's been bouncing back and forth in a never-ending cycle of big bangs in which all matter bubbles out of a singularity , followed by big crunches , in which everything gets swallowed up again to form that dense point from which the universe is born again .
And the cycle continues over and over and over .
The math of those theories , however , has never really worked out in a way that could tell us whether our universe is cyclic or has one beginning and @ @ @ @ @ @ @ team of theorists has invoked the powers of so-called to solve some fundamental riddles of the early universe .
The result could give us the theoretical push needed to build a universe from scratch , and hence lend support to a repeating universe .
Related : From Big Bang to present : snapshots of our universe through time If you want to build your own private theoretical model of the universe , be my guest .
Nobody will ever stop you from making your own cosmology .
But if you want to play @ @ @ @ @ @ @ have to play by its rules .
That means that no matter what your model of the cosmos contains , you have to confront some cold , hard observational evidence .
For instance , we know that we live in an expanding universe , in which galaxies and stars are flying away from us at an ever-increasing speed .
Scientists can tell that by using different types of techniques to calculate how fast galaxies at different distances from us are moving away .
We also have pictures of the baby universe , when @ @ @ @ @ @ @ and I really do mean `` baby , '' as the universe is currently 13.8 billion years old ) .
Within that baby picture , we see interesting patterns — tiny splotches and blotches that reveal the existence of slight temperature and pressure differences in that young universe .
We are able to explain all these observations ( and more ) with what 's called Big Bang cosmology , plus an additional idea known as inflation , which is a process that we think happened when the universe was less than a second @ @ @ @ @ @ @ itself lasted for the teensiest sliver of a second ) , the universe became much , much larger , taking quantum differences and making them bigger in the process .
Those differences eventually grew , as slightly denser patches had slightly stronger gravity , making them bigger .
Over time , those differences became large enough to imprint themselves as splotches in the baby picture of the universe ( and billions of years later , things like stars and galaxies , but that 's a separate story ) .
Tired of the and @ @ @ @ @ @ @ That 's fine , but you 'll have to explain things like the expansion of the universe and the splotches in the baby picture of cosmos .
In other words , you have to do a better job at explaining the universe than inflation does .
This seems easy , but it is n't .
The pressure , density and differences in the universe 's early years has bedeviled many alternative cosmologies , including one of the most popular let's-go-bigger-than-the-big-bang ideas , known as ( are you ready for this ) , Ekpyrotic @ @ @ @ @ @ @ the Greek for word for `` conflagration , '' which refers to an ancient philosophical idea of a constantly repeating universe .
In the Ekpyrotic scenario , the universe … constantly repeats .
Under that perspective , we are currently in a `` bang '' phase , which will eventually ( somehow ) slow down , stop , reverse , and crunch back down to incredibly high temperatures and pressures .
Then , the universe will ( somehow ) bounce back and re-ignite in a new big bang phase .
The trouble is @ @ @ @ @ @ @ blotches and splotches in the baby picture of the universe in an Ekpyrotic universe .
When we attempt to put together some vague physics to explain the crunch-bounce-bang cycle ( and I do emphasize `` vague '' here , because these processes involve energies and scales that we are n't even coming close to understanding with known physics ) , everything just comes out too … smooth .
No bumps .
No wiggles .
No splotches .
No differences in temperature , pressure or density .
And that does n't just mean the @ @ @ @ @ @ @ early universe .
It means that these cosmologies do n't lead to a universe filled with galaxies , stars or even people .
So that 's kind of a bummer .
Related : How will the universe end ?
The name of the game in the past few years of Ekpyrotic theories is to try to match the same observations that inflation does .
In the latest attempt to overcome this hurdle and make Ekpyrotic cosmologies at least somewhat respectable , a team of researchers invoke none other than the S-brane .
Right @ @ @ @ @ @ @ of string theory , right ?
That 's the universe of fundamental physics where every particle is really a tiny , vibrating string .
But a few years ago , theorists realized that the strings do n't have to be one-dimensional .
And the name they give to a multidimensional string ?
A brane .
As for the `` S '' part ?
Well most branes in string theory can roam around freely through both space and time , but the hypothetical S-brane can exist only in one instant in time , under @ @ @ @ @ @ @ Ekpyrotic scenario , when the universe was at its smallest and densest configuration possible , an S-brane appeared , triggering the re-expansion of a cosmos filled with matter and radiation ( a big bang ) and with small variations in temperature and pressure ( giving rise to the well-known splotches in the baby pictures of the universe ) .
That 's what three physicists propose in a new paper published online in July to the preprint server , meaning the paper has yet to be peer-reviewed .
Is this idea correct ?
Who @ @ @ @ @ @ @ theoretical ice recently , as experiments like those at the Large Hadron Collider have failed to find any hints of a theory known as supersymmetry , which is a critical underpinning of String theory .
And the concept of S-branes is itself a controversial idea within the String Theory community , as it 's not exactly known if branes would be allowed to exist only in one moment in time .
There 's also the fact that not only is the universe as we know it expanding , but it 's accelerating in @ @ @ @ @ @ @ of it slowing down ( let alone collapsing ) anytime soon .
Figuring out what could make it hit the brakes and reverse course , then , is tricky .
Still , Ekpyrotic ( and other ) ideas are worth exploring , because the earliest moments of the universe provide some of the most puzzling and challenging questions to modern physics .
Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute , host of Ask a Spaceman and Space Radio , and author of Your Place in the @ @

Has the universe been around forever? If so, perhaps it's been bouncing back and forth in a never-ending cycle of big bangs in which all matter bubbles out of a singularity, followed by big crunches, in which everything gets swallowed up again to form that dense point from which the universe is born again. And the cycle continues over and over and over.
The math of those theories, however, has never really worked out in a way that could tell us whether our universe is cyclic or has one beginning and one end. But recently, a team of theorists has invoked the powers of so-called string theory to solve some fundamental riddles of the early universe. The result could give us the theoretical push needed to build a universe from scratch, and hence lend support to a repeating universe.
Related: From Big Bang to present: snapshots of our universe through time
Painting the picture
If you want to build your own private theoretical model of the universe, be my guest. Nobody will ever stop you from making your own cosmology. But if you want to play the game of the universe, you have to play by its rules. That means that no matter what your model of the cosmos contains, you have to confront some cold, hard observational evidence.
For instance, we know that we live in an expanding universe, in which galaxies and stars are flying away from us at an ever-increasing speed. Scientists can tell that by using different types of techniques to calculate how fast galaxies at different distances from us are moving away. We also have pictures of the baby universe, when it was just 380,000 years old (and I really do mean "baby," as the universe is currently 13.8 billion years old).
Within that baby picture, we see interesting patterns — tiny splotches and blotches that reveal the existence of slight temperature and pressure differences in that young universe.
We are able to explain all these observations (and more) with what's called Big Bang cosmology, plus an additional idea known as inflation, which is a process that we think happened when the universe was less than a second old. During that process (which itself lasted for the teensiest sliver of a second), the universe became much, much larger, taking quantum differences and making them bigger in the process. Those differences eventually grew, as slightly denser patches had slightly stronger gravity, making them bigger. Over time, those differences became large enough to imprint themselves as splotches in the baby picture of the universe (and billions of years later, things like stars and galaxies, but that's a separate story).
King of the early universe
Tired of the Big Bang Theory and want your own version of cosmology? That's fine, but you'll have to explain things like the expansion of the universe and the splotches in the baby picture of cosmos. In other words, you have to do a better job at explaining the universe than inflation does.
This seems easy, but it isn't. The pressure, density and temperature differences in the universe's early years has bedeviled many alternative cosmologies, including one of the most popular let's-go-bigger-than-the-big-bang ideas, known as (are you ready for this), Ekpyrotic universe. The word ekpyrotic comes from the Greek for word for "conflagration," which refers to an ancient philosophical idea of a constantly repeating universe.
In the Ekpyrotic scenario, the universe … constantly repeats. Under that perspective, we are currently in a "bang" phase, which will eventually (somehow) slow down, stop, reverse, and crunch back down to incredibly high temperatures and pressures. Then, the universe will (somehow) bounce back and re-ignite in a new big bang phase.
The trouble is, it's hard to replicate the blotches and splotches in the baby picture of the universe in an Ekpyrotic universe. When we attempt to put together some vague physics to explain the crunch-bounce-bang cycle (and I do emphasize "vague" here, because these processes involve energies and scales that we aren't even coming close to understanding with known physics), everything just comes out too … smooth. No bumps. No wiggles. No splotches. No differences in temperature, pressure or density.
And that doesn't just mean the theories don't match observations of the early universe. It means that these cosmologies don't lead to a universe filled with galaxies, stars or even people.
So that's kind of a bummer.
Related: How will the universe end?
The S-brane saves the day
The name of the game in the past few years of Ekpyrotic theories is to try to match the same observations that inflation does. In the latest attempt to overcome this hurdle and make Ekpyrotic cosmologies at least somewhat respectable, a team of researchers invoke none other than the S-brane.
Right. S-branes. So you've heard of string theory, right? That's the universe of fundamental physics where every particle is really a tiny, vibrating string. But a few years ago, theorists realized that the strings don't have to be one-dimensional. And the name they give to a multidimensional string? A brane.
As for the "S" part? Well most branes in string theory can roam around freely through both space and time, but the hypothetical S-brane can exist only in one instant in time, under very special conditions.
In this new Ekpyrotic scenario, when the universe was at its smallest and densest configuration possible, an S-brane appeared, triggering the re-expansion of a cosmos filled with matter and radiation (a big bang) and with small variations in temperature and pressure (giving rise to the well-known splotches in the baby pictures of the universe). That's what three physicists propose in a new paper published online in July to the preprint server arXiv , meaning the paper has yet to be peer-reviewed.
Is this idea correct? Who knows. String theory is on thin theoretical ice recently, as experiments like those at the Large Hadron Collider have failed to find any hints of a theory known as supersymmetry, which is a critical underpinning of String theory . And the concept of S-branes is itself a controversial idea within the String Theory community, as it's not exactly known if branes would be allowed to exist only in one moment in time.
There's also the fact that not only is the universe as we know it expanding, but it's accelerating in its expansion, with no sign whatsoever of it slowing down (let alone collapsing) anytime soon. Figuring out what could make it hit the brakes and reverse course, then, is tricky.
Still, Ekpyrotic (and other) ideas are worth exploring, because the earliest moments of the universe provide some of the most puzzling and challenging questions to modern physics.
Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of Your Place in the Universe.
Originally published in Live Science.


livescience--2020-08-26--Britain's oldest artwork may depict mammoths from a drowned land

Britain 's oldest artwork has been unearthed on the Channel Island of Jersey , showing what appear to be scenes of mammoths in ancient lands now drowned by the sea .
The drawings are thought to be at least 15,000 years old At that time , a vast land bridge — now known as Doggerland — connected the British Isles to the European continent .
The drawings appear to show , a bovid animal like a bison or an ox , and a horse — all prey animals for human hunters at the time — as well as abstract patterns @ @ @ @ @ @ @ top of one another .
The images are engraved on 10 fragments of flat stone , known as plaquettes , uncovered at Les Varines , in southeast Jersey , between 2014 and 2018 .
The announcement of the discoveries and new research into their origins was in the journal .
The director of the excavations , geoarchaeologist Ed Blinkhorn of University College London , said the site was discovered after fragments of flint were brought up by a farmer ploughing nearby .
Flint is n't local to Jersey , so archaeologists knew the @ @ @ @ @ @ @ elsewhere , he said .
`` We traced this flow of material to its source — a largely intact saddle of land between an ancient sea stack [ a coastal rock formation ] and a buried granite cliff , '' Blinkhorn told Live Science .
Their excavations revealed a number of pits , traces of ( a pigmented mineral often used by prehistoric peoples for rituals and body paints ) , large slabs of granite and several hearths for fires , all protected by a layer of silt and clay , he said @ @ @ @ @ @ @ found near one of the hearths , and three were found under a nearby granite slab .
Plaquettes engraved with drawings have also been found in Portugal , Spain , France , southern Germany and Belgium ; and they are attributed to the Magdalenians , an early hunter-gatherer culture that flourished between 23,000 and 14,000 years ago .
`` These engraved stone fragments provide exciting and rare evidence of artistic expression at what was the farthest edge of the Magdalenian world , '' study co-author Chantal Connoller , an archaeologist at Newcastle University @ @ @ @ @ @ @ used to scratch fine lines on the plaquettes , and they appear to have been made by the same person in short succession , Connoller said .
The abstract designs use a combination of straight lines and longer , curved incisions.. One of the drawings shows the body of what may be a or ox , overlaid with the towering form and tusks of a mammoth .
A further overlaid drawing consists of roughly circular lines that may portray a human face .
But the drawings would have quickly faded — incising the @ @ @ @ @ @ @ that would have been only visible for a short time after they were made , Connoller said .
`` The act or moment of engraving was more meaningful than the object itself . ''
The island of Jersey , just 9 miles ( 14 kilometers ) wide , is much too small to support large animals , so any mammoths or herds of bison and must have been seen in lands now covered by the ocean .
The that once connected the British Isles to the European continent sank beneath rising sea waters @ @ @ @ @ @ @ Age , about 8,000 years ago .
It was warm and dry , however , for thousands of years before that , and scientists think the land was covered with forests and densely populated by animals , including small groups of early humans .
Several have been dredged or fished up from the sunken lands , especially in the shallow area of the English Channel known as Dogger Bank , which gives the region its name .
The researchers think the site at Les Varines was a temporary encampment used by a Magdalenian @ @ @ @ @ @ @ as the weather and hunting stayed good .
But the deliberate decoration of the stone fragments hints at more permanent settlements , Conneller said .
`` The engraved stones are firmly domestic art , '' she said .
`` The people at Les Varines are likely to have been pioneer colonisers of the region , and creating engraved objects at new settlements may have been a way of creating symbolic relationships with new places . ''

The drawings engraved on the stone plaquettes from the ancient site on the Channel Island of Jersey are thought to be about 15,000 years old, making them the oldest artworks found in Britain.
Britain's oldest artwork has been unearthed on the Channel Island of Jersey, showing what appear to be Ice Age scenes of mammoths in ancient lands now drowned by the sea.
The drawings are thought to be at least 15,000 years old At that time, a vast land bridge — now known as Doggerland — connected the British Isles to the European continent.
The drawings appear to show mammoths , a bovid animal like a bison or an ox, and a horse — all prey animals for human hunters at the time — as well as abstract patterns. Many of them are overlaid on top of one another.
Related: The world's oldest cave art
The images are engraved on 10 fragments of flat stone, known as plaquettes, uncovered at Les Varines, in southeast Jersey, between 2014 and 2018.
The announcement of the discoveries and new research into their origins was published Aug. 19 in the journal PLOS ONE .
The director of the excavations, geoarchaeologist Ed Blinkhorn of University College London, said the site was discovered after fragments of flint were brought up by a farmer ploughing nearby.
Flint isn't local to Jersey, so archaeologists knew the material must have been carried there from elsewhere, he said.
"We traced this flow of material to its source — a largely intact saddle of land between an ancient sea stack [a coastal rock formation] and a buried granite cliff," Blinkhorn told Live Science.
Their excavations revealed a number of pits, traces of ochre (a pigmented mineral often used by prehistoric peoples for rituals and body paints), large slabs of granite and several hearths for fires, all protected by a layer of silt and clay, he said.
Ancient artworks
Most of the stone plaquettes were found near one of the hearths, and three were found under a nearby granite slab.
Plaquettes engraved with drawings have also been found in Portugal, Spain, France, southern Germany and Belgium; and they are attributed to the Magdalenians, an early hunter-gatherer culture that flourished between 23,000 and 14,000 years ago.
Related: Stone age cannibals engraved marks on human bones
"These engraved stone fragments provide exciting and rare evidence of artistic expression at what was the farthest edge of the Magdalenian world," study co-author Chantal Connoller, an archaeologist at Newcastle University in England, said in a statement .
Stone tools were used to scratch fine lines on the plaquettes, and they appear to have been made by the same person in short succession, Connoller said.
The abstract designs use a combination of straight lines and longer, curved incisions..
One of the drawings shows the body of what may be a bison or ox, overlaid with the towering form and tusks of a mammoth. A further overlaid drawing consists of roughly circular lines that may portray a human face.
But the drawings would have quickly faded — incising the stones created a powder in the lines that would have been only visible for a short time after they were made, Connoller said. "The act or moment of engraving was more meaningful than the object itself."
Some of the ancient drawings are overlaid on each other. The engravings on this stone fragment are thought to show a bovid animal like an ox or bison; the outline of a mammoth; and circular scratches that could portray a human face. (Image credit: Silvia Bello/Natural History Museum London)
Drowned lands
The island of Jersey, just 9 miles (14 kilometers) wide, is much too small to support large animals, so any mammoths or herds of bison and horses must have been seen in lands now covered by the ocean.
The Doggerland land bridge that once connected the British Isles to the European continent sank beneath rising sea waters after the end of the last Ice Age, about 8,000 years ago.
It was warm and dry, however, for thousands of years before that, and scientists think the land was covered with forests and densely populated by animals, including small groups of early humans.
Several ancient human bones and Stone Age artifacts have been dredged or fished up from the sunken lands, especially in the shallow area of the English Channel known as Dogger Bank, which gives the region its name.
The researchers think the site at Les Varines was a temporary encampment used by a Magdalenian group who lived there only as long as the weather and hunting stayed good.
But the deliberate decoration of the stone fragments hints at more permanent settlements, Conneller said.
"The engraved stones are firmly domestic art," she said. "The people at Les Varines are likely to have been pioneer colonisers of the region, and creating engraved objects at new settlements may have been a way of creating symbolic relationships with new places."
Originally published on Live Science.


livescience--2020-08-25--Laura expected to slam into Texas and Louisiana as a Category 3 hurricane

Tropical storm Laura is now a , and it 's expected to grow even more powerful as it whirls toward Louisiana and Texas .
The storm passed over Cuba and into the Gulf of Mexico Tuesday morning ( Aug. 25 ) , strengthening into a hurricane even as the scattered remains of tropical storm Marco drifted away from the site of their Louisiana landfall .
Laura is expected to pick up energy from the warm gulf waters in the next couple days , then make landfall as a Category 3 `` major hurricane '' — 2020 's first — with @ @ @ @ @ @ @ ( 178 km/h ) , according to the ( NHC ) .
As with most tropical cyclones , the most significant threat from Laura is flooding , not wind .
Already , as a tropical storm , it has killed 13 people on the island of Hispaniola .
Eleven of those who died were in Haiti and two in the Dominican Republic , according to .
Haitian authorities posted this video of the flooding : In Puerto Rico , reported that two teenagers spent all night on a rock in the middle of @ @ @ @ @ @ @ , while rescue teams tried to reach them through the floodwaters .
The 19-year-old and 17-year-old arrived at the popular El Morón pool in the river , seeing sunny skies despite the storm warnings .
They became stuck as Laura dumped water into the river , and remained trapped as the floodwaters and storm conditions thwarted multiple rescue attempts .
By early morning , the water levels subsided enough for rescuers to reach them .
Related : Hurricane season : How long it lasts and what to expect When Laura hits the U.S. @ @ @ @ @ @ @ , it will push an even stronger storm surge ahead of it and dump much more rain than Marco .
According to the NHC , the storm surge between High Island , Texas and Morgan City , Louisiana could reach 7 to 11 feet ( 2.1 to 3.4 meters ) .
Four to 6 feet ( 1.2 to 1.8 m ) are possible across an even wider area , between Port Bolivar , Texas ( just east of Galveston ) and the mouth of the Mississippi River , just west of New Orleans @ @ @ @ @ @ @ feet up to 4 feet ( 0.6 to 1.2 m ) are expected all the way from San Luis Pass , Texas ( south of Houston ) to Ocean Springs , Mississippi , a span of 388 miles ( 625 kilometers ) .
These details could change as the hurricane approaches land , but time to prepare is limited .
Tropical storm-force winds , meaning winds of 39-73 mph ( 63–118 km/h ) , could arrive in the area as early as Wednesday afternoon ( Aug. 26 ) , according to the NHC @ @ @ @ @ @ @ evacuation orders along their coasts .
That means that six states have ordered natural disaster evacuations this month , with people in California , Oregon , Washington and Colorado having to flee severe wildfires .
As Live Science previously reported , evacuations during a global pandemic can add another layer of complexity to an already fraught situation .
Evacuations will potentially contribute to the new coronavirus 's spread , as people who would otherwise shelter in place congregate with others , according to research from Columbia University .
Wildfires , major hurricanes and @ @ @ @ @ @ @ threats due to climate change , several studies have shown .
What 's more , Laura is a record-setting in its own right ; the storm system is the earliest 13th tropical cyclone of any year on the books , as meteorologist Matt Lanza noted .
Eight other storms this year have set similar records , making 2020 already one of the busiest tropical cyclone seasons ever .

Tropical storm Laura is now a hurricane , and it's expected to grow even more powerful as it whirls toward Louisiana and Texas.
The storm passed over Cuba and into the Gulf of Mexico Tuesday morning (Aug. 25), strengthening into a hurricane even as the scattered remains of tropical storm Marco drifted away from the site of their Louisiana landfall. Laura is expected to pick up energy from the warm gulf waters in the next couple days, then make landfall as a Category 3 "major hurricane" — 2020's first — with wind speeds of at least 111 mph (178 km/h), according to the National Hurricane Center (NHC).
As with most tropical cyclones, the most significant threat from Laura is flooding, not wind. Already, as a tropical storm, it has killed 13 people on the island of Hispaniola. Eleven of those who died were in Haiti and two in the Dominican Republic, according to The Weather Channel . Haitian authorities posted this video of the flooding:
#TTLaura: Anpil lapli gentan tonbe plizyè kote nan peyi, sitou nan Lwès ak nan Sidès. Sonje : dlo k ap desann PA JWE‼#SezonSiklòn2020 #Laura pic.twitter.com/y5MlBEFWL8August 23, 2020 See more
In Puerto Rico, El Nuevo Dia reported that two teenagers spent all night on a rock in the middle of the Toro Negro River, in Ciales, while rescue teams tried to reach them through the floodwaters. The 19-year-old and 17-year-old arrived at the popular El Morón pool in the river, seeing sunny skies despite the storm warnings. They became stuck as Laura dumped water into the river, and remained trapped as the floodwaters and storm conditions thwarted multiple rescue attempts. By early morning, the water levels subsided enough for rescuers to reach them.
Related: Hurricane season: How long it lasts and what to expect
When Laura hits the U.S. coast Thursday morning (Aug. 27), it will push an even stronger storm surge ahead of it and dump much more rain than Marco. According to the NHC, the storm surge between High Island, Texas and Morgan City, Louisiana could reach 7 to 11 feet (2.1 to 3.4 meters). Four to 6 feet (1.2 to 1.8 m) are possible across an even wider area, between Port Bolivar, Texas (just east of Galveston) and the mouth of the Mississippi River, just west of New Orleans. Storm surges of at least 2 feet up to 4 feet (0.6 to 1.2 m) are expected all the way from San Luis Pass, Texas (south of Houston) to Ocean Springs, Mississippi, a span of 388 miles (625 kilometers).
These details could change as the hurricane approaches land, but time to prepare is limited. Tropical storm-force winds, meaning winds of 39-73 mph (63–118 km/h), could arrive in the area as early as Wednesday afternoon (Aug. 26), according to the NHC.
Louisiana and Texas have both issued evacuation orders along their coasts. That means that six states have ordered natural disaster evacuations this month, with people in California, Oregon, Washington and Colorado having to flee severe wildfires. As Live Science previously reported, evacuations during a global pandemic can add another layer of complexity to an already fraught situation. Evacuations will potentially contribute to the new coronavirus's spread, as people who would otherwise shelter in place congregate with others, according to research from Columbia University.
Wildfires, major hurricanes and global pandemics are all becoming more severe threats due to climate change, several studies have shown.
What's more, Laura is a record-setting in its own right; the storm system is the earliest 13th tropical cyclone of any year on the books, as meteorologist Matt Lanza noted.
The 2020 season has set the record for the earliest C, E, F, G, H, I, J, and K storms. Go ahead and snipe about some of these storms being subpar or maybe not named in the pre-satellite era, but whatever the case...we're beating 2005 in quantity (not quality).August 14, 2020 See more
Eight other storms this year have set similar records, making 2020 already one of the busiest tropical cyclone seasons ever.
Originally published on Live Science.


livescience--2020-08-25--What are locusts and why do they swarm?

What are locusts and why do they swarm?

Locusts are large grasshoppers that live on almost every continent of the world and are known for their propensity to gather in large , destructive swarms .
However , locusts often live for several generations , spanning decades , in the solitary , sedentary style that 's characteristic of other species of grasshoppers .
It 's when locusts come together that their behavior changes .
Locusts are able to sense when their population density begins to increase , said Hojun Song , an entomologist at Texas A & M University .
And in response , `` they become gregarious , @ @ @ @ @ @ @ more [ and ] develop faster , '' he said .
But the conditions must be just right for locusts to join forces .
Sudden rainfall , for example , could help feed a growing population and cause flooding that corrals locusts together and attract more locusts to join .
What starts as a small group can turn into a thrumming swarm of thousands , millions or even billions of locusts .
As part of this transformation , locusts may change color , Song said .
Some species of locusts become migratory , @ @ @ @ @ @ @ of food .
The most devastating , best-known , and most frequently studied example is the desert locust ( Schistocerca gregaria ) .
`` Unlike other pests , which are localized , desert locusts can swarm and fly , and an entire region can be wiped out of crops , '' as the locusts come through and chow down , said Esther Ngumbi , an entomologist at the University of Illinois at Urbana-Champaign who studies agricultural pests and food insecurity .
The enormous swarms of desert locusts can be utterly devastating for famers @ @ @ @ @ @ @ , she said .
There are about 20 species of locusts , and they all undergo a dramatic transformation when there are many other locusts of the same species nearby .
The locusts shift from what scientists call the solitarious , or solitary phase when the locust is alone , to the gregarious phase when they swarm together .
The specific signal that instigates the phase shift varies from species to species , Song said .
For example , although both species react to the sight and smell of other locusts in a @ @ @ @ @ @ @ shift into the gregarious phase with a touch on the hind legs , whereas the sensitive area on the Australian plague locust ( Chortoicetes terminifera ) is its antennae , he explained .
These triggers seem to boost levels of serotonin , the same chemical associated with mood in humans .
The two `` Jekyll and Hyde '' versions of the locust are an example of a phenomenon called `` phenotypic plasticity . ''
This happens when the genes of the animal go unchanged , but the behavior and physiology changes in response @ @ @ @ @ @ @ are fixed , and certain traits change in response to the environment , '' Song said .
`` This is common across all life forms , including us . ''
One theory to explain why locusts adapted to have such phase changes , according to Song , is that the switch is a response to a changing environment .
About 8 million years ago , as Northern Africa shifted from tropical forests to desert , migratory swarming locusts could hop from one oasis of vegetation to the next , or shift back to @ @ @ @ @ @ @ of food and space in one place .
Understanding the basic biology of locusts can provide insight into dealing with them as an agricultural pest , but also plays a part in the classic debate over the roles of nature and nurture — or genetic material and the environment — in shaping individuals .
Locusts are found on every continent except Antarctica .
In North America , the Rocky Mountain locust ( Melanoplus spretus ) has been extinct for a century , but other locust species remain in Mexico .
Depending on the @ @ @ @ @ @ @ travel hundreds of miles in search of food .
For instance , in 1988 a swarm flew from West Africa to the Caribbean , a journey of more than 3,100 miles ( 5,000 kilometers ) in merely 10 days , according to National Geographic .
The ability to traverse such distances make locusts `` a continental challenge '' as an agricultural pest , said Arianne Cease , director of the Global Locust Initiative at Arizona State University .
Effective monitoring and management of locusts require international cooperation .
Related : The science of @ @ @ @ @ @ @ although there are reports of locust cannibalism when other food is scarce , Song said .
A locust can eat its own weight in plant matter each day , which is only about 0.07 ounces ( 2 grams ) .
But the largest locust swarms , called plagues , can number in the billions and together , a plague of locusts can consume so much plant material that they erase several months of growth before moving on , resulting in long-term effects on the health and finances of entire regions .
For example @ @ @ @ @ @ @ originated in Western Africa in 2003 and lasted until 2005 affected 22 countries and reportedly wiped out over 80 % of crops , according to a report from the Food and Agriculture Organization of the United Nations .
By the time the plague finally declined in early 2005 , the total cost of damage control efforts had reached half a billion dollars .
Some locust species , like the desert locust , normally live in the wilderness , Cease said .
Monitoring for small outbreaks of these locust populations can help keep the @ @ @ @ @ @ @ their swarm grows to a size large enough to cause national or multinational disasters .
Other locusts , such as the Sengalese grasshopper ( Oedaleus senegalensis ) , may live in agricultural areas even when in the solitary phase .
Careful land management , such as carefully selecting crops and how to grow them , and controlling nutrients in the soil can help discourage those locust swarms from forming , Cease said .
Locust plagues may last for years once they are in full swing , with multiple generations of swarming locusts .
@ @ @ @ @ @ @ , and some species go decades between major population explosions .
However , experts say this is an additional challenge for disaster preparedness because the threat of a locust swarm can seem less critical if it has n't been an issue for many years .
Although their swarming behavior does n't happen often , locusts are typically thought of as fearsome pests prone to causing natural disasters .
And although locusts do n't bite people , people bite them .
Locusts are edible and several cuisines around the world include locust recipes , @ @ @ @ @ @ @ But because modern farmers may use pesticides to protect their crops from locusts , eating locusts can be unsafe as they may be carrying residue from those pesticides .
Locusts are often confused with periodical cicadas , another type of large insect that shows up in large numbers every few years .
Although cicadas may be called `` locusts , '' they 're technically not locusts , or even grasshoppers .
Periodical cicadas synchronously emerge from the ground every 13 or 17 years , depending on the species , according to the National @ @ @ @ @ @ @ human-driven climate change , experts warn that the threat of locust swarms may intensify .
It 's unclear exactly how climate change will affect all locust populations , but the insects are resilient , and some scientists have warned that the severity of locust plagues could worsen if conditions for locust swarming become more common .
For instance , an increase in cyclones in Eastern Africa and the Arabian Peninsula , a weather condition favorable to locusts , could lead to higher locust numbers , according to National Geographic .
`` With climate @ @ @ @ @ @ @ a force to be reckoned with , '' Ngumbi told Live Science .
The worst consequences may be borne by people who bear little responsibility for the changing climate , such as small-scale farmers and those living in rural communities .
Because locusts can wreak such incredible havoc on crops , food insecurity is legitimate concern , Ngumbi said .
Although people have lived with locusts for millennia , there are still many unanswered questions about how human activities may influence locust plague formation , Cease said .
`` How does the social @ @ @ @ @ @ @ '' she asked .
The Global Locust Initiative 's interdisciplinary research aims to find solutions for the international challenge of dealing with locust swarms and improve food stability worldwide .
• Find out how researchers at Harvard University are studying locust swarms in East Africa .
• Watch locusts swarming in Madagascar in this video from CNN .
• Learn more about how locusts phase shift when their population begins to swell , from the Entomological Society of America .

Locusts are large grasshoppers that live on almost every continent of the world and are known for their propensity to gather in large, destructive swarms. However, locusts often live for several generations, spanning decades, in the solitary, sedentary style that's characteristic of other species of grasshoppers. It's when locusts come together that their behavior changes.
Locusts are able to sense when their population density begins to increase, said Hojun Song, an entomologist at Texas A&M University. And in response, "they become gregarious, attracted to each other. They eat more [and] develop faster," he said.
Related: Grasshoppers vs. locusts: What makes a swarm?
But the conditions must be just right for locusts to join forces. Sudden rainfall, for example, could help feed a growing population and cause flooding that corrals locusts together and attract more locusts to join. What starts as a small group can turn into a thrumming swarm of thousands, millions or even billions of locusts. As part of this transformation, locusts may change color, Song said.
Some species of locusts become migratory, flying long distances across borders in search of food. The most devastating, best-known, and most frequently studied example is the desert locust (Schistocerca gregaria).
"Unlike other pests, which are localized, desert locusts can swarm and fly, and an entire region can be wiped out of crops," as the locusts come through and chow down, said Esther Ngumbi, an entomologist at the University of Illinois at Urbana-Champaign who studies agricultural pests and food insecurity. The enormous swarms of desert locusts can be utterly devastating for famers whose livelihoods depend solely on those crops, she said.
Locust phases: Shifting from solitary to swarming
There are about 20 species of locusts, and they all undergo a dramatic transformation when there are many other locusts of the same species nearby. The locusts shift from what scientists call the solitarious, or solitary phase when the locust is alone, to the gregarious phase when they swarm together.
The specific signal that instigates the phase shift varies from species to species, Song said. For example, although both species react to the sight and smell of other locusts in a laboratory setting, the desert locust can shift into the gregarious phase with a touch on the hind legs, whereas the sensitive area on the Australian plague locust (Chortoicetes terminifera) is its antennae, he explained. These triggers seem to boost levels of serotonin, the same chemical associated with mood in humans.
Related: Image gallery: Striking photos of locust swarms
The two "Jekyll and Hyde" versions of the locust are an example of a phenomenon called "phenotypic plasticity." This happens when the genes of the animal go unchanged, but the behavior and physiology changes in response to external factors. "Certain traits are fixed, and certain traits change in response to the environment," Song said. "This is common across all life forms, including us."
One theory to explain why locusts adapted to have such phase changes, according to Song, is that the switch is a response to a changing environment. About 8 million years ago, as Northern Africa shifted from tropical forests to desert, migratory swarming locusts could hop from one oasis of vegetation to the next, or shift back to a solitary phase if there was plenty of food and space in one place.
Understanding the basic biology of locusts can provide insight into dealing with them as an agricultural pest, but also plays a part in the classic debate over the roles of nature and nurture — or genetic material and the environment — in shaping individuals.
Locust plagues
Locusts are found on every continent except Antarctica. In North America, the Rocky Mountain locust (Melanoplus spretus) has been extinct for a century, but other locust species remain in Mexico. Depending on the species, a flying locust swarm may travel hundreds of miles in search of food.
For instance, in 1988 a swarm flew from West Africa to the Caribbean, a journey of more than 3,100 miles (5,000 kilometers) in merely 10 days, according to National Geographic. The ability to traverse such distances make locusts "a continental challenge" as an agricultural pest, said Arianne Cease, director of the Global Locust Initiative at Arizona State University. Effective monitoring and management of locusts require international cooperation.
Related: The science of the 10 plagues
Locusts are herbivores, although there are reports of locust cannibalism when other food is scarce, Song said. A locust can eat its own weight in plant matter each day, which is only about 0.07 ounces (2 grams). But the largest locust swarms, called plagues, can number in the billions and together, a plague of locusts can consume so much plant material that they erase several months of growth before moving on, resulting in long-term effects on the health and finances of entire regions.
For example, a plague of desert locusts that originated in Western Africa in 2003 and lasted until 2005 affected 22 countries and reportedly wiped out over 80% of crops, according to a report from the Food and Agriculture Organization of the United Nations. By the time the plague finally declined in early 2005, the total cost of damage control efforts had reached half a billion dollars.
Some locust species, like the desert locust, normally live in the wilderness, Cease said. Monitoring for small outbreaks of these locust populations can help keep the problems manageable by suppressing the locusts before their swarm grows to a size large enough to cause national or multinational disasters.
Related: New weapon against desert locust plagues: Satellite images
Other locusts, such as the Sengalese grasshopper (Oedaleus senegalensis), may live in agricultural areas even when in the solitary phase. Careful land management, such as carefully selecting crops and how to grow them, and controlling nutrients in the soil can help discourage those locust swarms from forming, Cease said.
Locust plagues may last for years once they are in full swing, with multiple generations of swarming locusts. But the worst plagues are generally infrequent, and some species go decades between major population explosions. However, experts say this is an additional challenge for disaster preparedness because the threat of a locust swarm can seem less critical if it hasn't been an issue for many years.
A desert locust chows down on a leaf. (Image credit: Shutterstock)
How locusts affect humans
Although their swarming behavior doesn't happen often, locusts are typically thought of as fearsome pests prone to causing natural disasters. And although locusts don't bite people, people bite them. Locusts are edible and several cuisines around the world include locust recipes, such as peanut-stuffed locusts in Cambodia. But because modern farmers may use pesticides to protect their crops from locusts, eating locusts can be unsafe as they may be carrying residue from those pesticides.
Locusts are often confused with periodical cicadas, another type of large insect that shows up in large numbers every few years. Although cicadas may be called "locusts," they're technically not locusts, or even grasshoppers. Periodical cicadas synchronously emerge from the ground every 13 or 17 years, depending on the species, according to the National Wildlife Foundation.
Related: Gaddafi's fall leads to desert locusts' rise
In this era of human-driven climate change, experts warn that the threat of locust swarms may intensify. It's unclear exactly how climate change will affect all locust populations, but the insects are resilient, and some scientists have warned that the severity of locust plagues could worsen if conditions for locust swarming become more common. For instance, an increase in cyclones in Eastern Africa and the Arabian Peninsula, a weather condition favorable to locusts, could lead to higher locust numbers, according to National Geographic. "With climate change, insects are going to be a force to be reckoned with," Ngumbi told Live Science.
The worst consequences may be borne by people who bear little responsibility for the changing climate, such as small-scale farmers and those living in rural communities. Because locusts can wreak such incredible havoc on crops, food insecurity is legitimate concern, Ngumbi said.
Although people have lived with locusts for millennia, there are still many unanswered questions about how human activities may influence locust plague formation, Cease said. "How does the social system interact with the natural system?" she asked. The Global Locust Initiative's interdisciplinary research aims to find solutions for the international challenge of dealing with locust swarms and improve food stability worldwide.
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livescience--2020-08-25--Africa declared free of wild poliovirus

Africa declared free of wild poliovirus

Africa is free of wild poliovirus , after decades of vaccination campaigns , according to news reports .
An independent body called the Africa Regional Certification Commission ( ARCC ) for Polio Eradication made the announcement today ( Aug. 25 ) during a World Health Organization ( WHO ) videoconference , .
Of the 47 countries within the WHO 's Africa region , Nigeria eradicated the most recently , and now , four years have passed since the country 's most recent wild polio case .
The disease known as polio is caused by three different strains of , which @ @ @ @ @ @ @ cord and causes partial or complete paralysis , .
The majority of people who catch polio do n't become paralyzed , but those who do can remain permanently disabled or die from the condition , as the muscles that support breathing can be paralyzed , according to the Centers for Disease Control and Prevention ( CDC ) .
People can catch polioviruses through contact with the feces of an infected person , or through contaminated food , water and objects that come in contact with the mouth , according to the CDC .
@ @ @ @ @ @ @ when an infected person sneezes or coughs .
While there is no specific treatment for polio , a full course of polio vaccinations is more than 99 % effective at preventing the infection , .
To snuff out wild poliovirus in Nigeria , a coalition of national governments and local leaders called the Global Polio Eradication Initiative coordinated a campaign to vaccinate children in Borno State , located in the northeast region of the country , .
In addition to administering vaccinations , the coalition improved surveillance systems to monitor for polio outbreaks @ @ @ @ @ @ @ awareness of the campaign , Dr. Matshidiso Moeti , the World Health Organization ( WHO ) regional director for Africa , said in a news conference , according to The Guardian .
Health care workers also faced threat of attack from the Boko Haram insurgency in northern Nigeria , as well as occasional violence from local communities who opposed the vaccination effort due to concerns about its effects .
To protect health care workers , the coalition worked with military members and a government-approved militia who acted as their escorts , Dr. Tunji @ @ @ @ @ @ @ the nonprofit Rotary International , told Reuters .
Including polio survivors on eradication teams proved essential to gaining the trust of local communities , Misbahu Lawan Didi , president of the Nigerian Polio Survivors Association , .
`` Many rejected the polio , but they see how much we struggle to reach them , sometimes crawling large distances , to speak to them , '' Didi said .
`` We ask them : 'Do n't you think it is important for you to protect your child not to be like us ? '
@ @ @ @ @ @ @ efforts , Africa has been declared free of wild poliovirus — but the work is n't over yet .
Oral polio vaccines , including those used in Africa , contain a weakened poliovirus that can sometimes mutate into a form that behaves like the wild virus and can infect unvaccinated individuals , according to the CDC .
In areas with low vaccine coverage , outbreaks of vaccine-derived poliovirus can occur even when wild strains of the virus have been eliminated .
Nigeria and 15 other African countries are currently experiencing small outbreaks of @ @ @ @ @ @ @ in total , 177 cases of vaccine-derived poliovirus have been reported in Africa this year , according to BBC News .
To avoid vaccine-derived polio , the U.S. stopped administering oral polio vaccines in 2000 and now exclusively uses a so-called inactivated poliovirus vaccine , which is delivered as a shot and contains a dead poliovirus , rather than a weakened one .
`` The global eradication of polio requires stopping all [ oral polio vaccines ] in routine immunization , as soon as possible after the eradication of wild poliovirus transmission , @ @ @ @ @ @ @ wild poliovirus eliminated in Africa , `` we must stay vigilant and keep up vaccination rates to avert a resurgence of the wild poliovirus and address the continued threat of the vaccine-derived polio , '' Moeti said in the news conference , according to The Guardian .
Wild poliovirus could reemerge in Africa , given that the virus still circulates in Afghanistan and Pakistan , Michael Galway , a polio expert at the Bill and Melinda Gates Foundation , told Reuters .
`` Until wild poliovirus is eradicated everywhere , it ’ s @ @ @ @ @ @ @ said .

Africa is free of wild poliovirus, after decades of vaccination campaigns, according to news reports.
An independent body called the Africa Regional Certification Commission (ARCC) for Polio Eradication made the announcement today (Aug. 25) during a World Health Organization (WHO) videoconference, Reuters reported . Of the 47 countries within the WHO's Africa region, Nigeria eradicated the virus most recently, and now, four years have passed since the country's most recent wild polio case.
The disease known as polio is caused by three different strains of poliovirus , which sometimes attacks nerve cells in the spinal cord and causes partial or complete paralysis, Live Science previously reported . The majority of people who catch polio don't become paralyzed, but those who do can remain permanently disabled or die from the condition, as the muscles that support breathing can be paralyzed, according to the Centers for Disease Control and Prevention (CDC).
Related: The 12 deadliest viruses on Earth
People can catch polioviruses through contact with the feces of an infected person, or through contaminated food, water and objects that come in contact with the mouth, according to the CDC. Less commonly, the virus can spread when an infected person sneezes or coughs. While there is no specific treatment for polio, a full course of polio vaccinations is more than 99% effective at preventing the infection, the CDC says .
To snuff out wild poliovirus in Nigeria, a coalition of national governments and local leaders called the Global Polio Eradication Initiative coordinated a campaign to vaccinate children in Borno State, located in the northeast region of the country, The Guardian reported .
In addition to administering vaccinations, the coalition improved surveillance systems to monitor for polio outbreaks and worked with polio survivors to raise awareness of the campaign, Dr. Matshidiso Moeti, the World Health Organization (WHO) regional director for Africa, said in a news conference, according to The Guardian. Health care workers also faced threat of attack from the Boko Haram insurgency in northern Nigeria, as well as occasional violence from local communities who opposed the vaccination effort due to concerns about its effects.
To protect health care workers, the coalition worked with military members and a government-approved militia who acted as their escorts, Dr. Tunji Funsho, a Nigerian anti-polio coordinator for the nonprofit Rotary International, told Reuters. Including polio survivors on eradication teams proved essential to gaining the trust of local communities, Misbahu Lawan Didi, president of the Nigerian Polio Survivors Association, told BBC News .
Related: 5 dangerous myths about vaccines
"Many rejected the polio vaccine , but they see how much we struggle to reach them, sometimes crawling large distances, to speak to them," Didi said. "We ask them: 'Don't you think it is important for you to protect your child not to be like us?'"
Now, thanks to these extensive efforts, Africa has been declared free of wild poliovirus — but the work isn't over yet. Oral polio vaccines, including those used in Africa, contain a weakened poliovirus that can sometimes mutate into a form that behaves like the wild virus and can infect unvaccinated individuals, according to the CDC . In areas with low vaccine coverage, outbreaks of vaccine-derived poliovirus can occur even when wild strains of the virus have been eliminated.
Nigeria and 15 other African countries are currently experiencing small outbreaks of vaccine-derived poliovirus, Reuters reported, and in total, 177 cases of vaccine-derived poliovirus have been reported in Africa this year, according to BBC News. To avoid vaccine-derived polio, the U.S. stopped administering oral polio vaccines in 2000 and now exclusively uses a so-called inactivated poliovirus vaccine, which is delivered as a shot and contains a dead poliovirus, rather than a weakened one.
"The global eradication of polio requires stopping all [oral polio vaccines] in routine immunization, as soon as possible after the eradication of wild poliovirus transmission," the CDC website notes. With wild poliovirus eliminated in Africa, "we must stay vigilant and keep up vaccination rates to avert a resurgence of the wild poliovirus and address the continued threat of the vaccine-derived polio," Moeti said in the news conference, according to The Guardian.
Wild poliovirus could reemerge in Africa, given that the virus still circulates in Afghanistan and Pakistan, Michael Galway, a polio expert at the Bill and Melinda Gates Foundation, told Reuters. "Until wild poliovirus is eradicated everywhere, it’s still a risk everywhere," he said.
Originally published on Live Science.


livescience--2020-08-25--Stash of pure, 24-carat gold coins unearthed in Israel

About 1,100 years ago , someone stashed a small fortune of pure gold coins in a clay jar and nailed that jar to a hole in the ground , likely with the hopes of retrieving it one day .
Whoever it was , they never reclaimed the treasure .
The hoard — a hefty pile of 425 gold coins — remained buried until a group of youths volunteering ahead of their mandatory army service in Israel unearthed it on Aug. 18 , according to the Israel Antiquities Authority ( IAA ) , which organized the excavation .
`` I dug @ @ @ @ @ @ @ the soil , saw what looked like very thin leaves , '' Oz Cohen , one of the youths , said in an IAA statement .
`` When I looked again I saw these were gold coins .
It was really exciting to find such a special and ancient treasure . ''
Most of the 24-carat gold coins date to the Abbasid period , also known as the Islamic Golden Age .
The Abbasid caliphate ( A.D. 750–1258 ) ruled from what is now Iraq , where innovations in art and architecture led @ @ @ @ @ @ @ become the cultural capitals of the Muslim world , according to The Metropolitan Museum of Art in New York City .
At its height in A.D. 850 , the caliphate ruled parts of Northern Africa and much of the Middle East .
The caliphate fell when the Mongols sacked Baghdad in 1258 .
`` Finding gold coins , certainly in such a considerable quantity , is extremely rare , '' Liat Nadav-Ziv and Elie Haddad , who directed the IAA excavation , said in the statement .
`` We almost never find them @ @ @ @ @ @ @ has always been extremely valuable , melted down and reused from generation to generation . ''
The coins are in `` excellent condition , as if buried the day before , '' because they were made of pure gold , meaning that they wo n't oxidize when exposed to air , Nadav-Ziv and Haddad added .
The 1.8-lbs .
( 845 grams ) hoard was `` a significant amount of money in those days , '' Robert Kool , a coin expert at the IAA said in the statement .
`` For example @ @ @ @ @ @ @ person could buy a luxurious house in one of the best neighborhoods in Fustat , the enormous wealthy capital of Egypt in those days . ''
( Today , based on the current price of gold per gram , that pot of gold would be worth approximately $ 52,600 . )
The hoard is one of the earliest known gold caches from the end of the ninth century in what is now Israel , Kool noted .
The stash includes full gold dinars and about 270 small gold cuttings , `` pieces of @ @ @ @ @ @ @ change , ' a regular practice in Islamic countries after the 850s , when bronze and copper coins fell out of use . ''
One of the cuttings is an exceptional artifact that has never been found before in Israel .
This particular piece is a fragment of a gold solidus , a nearly pure gold coin , depicting the Byzantine emperor Theophilos ( A.D. 829 – 842 ) , and minted in the empire ’ s capital of Constantinople .
Its presence in the hoard of Islamic coins is evidence of monetary @ @ @ @ @ @ @ , between the two rival empires from this period .
`` This rare treasure will certainly be a major contribution to research , as finds from the Abbasid period in Israel are relatively few , '' Kool said .
`` Hopefully the study of the hoard will tell us more about a period of which we still know very little . ''
Editor 's Note : This story was updated to fix a numerical conversion .
The gold stash weighed 1.8 lbs .
( 845 grams ) .

About 1,100 years ago, someone stashed a small fortune of pure gold coins in a clay jar and nailed that jar to a hole in the ground, likely with the hopes of retrieving it one day.
Whoever it was, they never reclaimed the treasure. The hoard — a hefty pile of 425 gold coins — remained buried until a group of youths volunteering ahead of their mandatory army service in Israel unearthed it on Aug. 18, according to the Israel Antiquities Authority (IAA), which organized the excavation.
"I dug in the ground and when I excavated the soil, saw what looked like very thin leaves," Oz Cohen, one of the youths, said in an IAA statement. "When I looked again I saw these were gold coins. It was really exciting to find such a special and ancient treasure."
Related: The Holy Land: 7 amazing archaeological finds
Most of the 24-karat gold coins date to the Abbasid period, also known as the Islamic Golden Age. The Abbasid caliphate (A.D. 750–1258) ruled from what is now Iraq, where innovations in art and architecture led the cities of Baghdad and Samarra to become the cultural capitals of the Muslim world, according to The Metropolitan Museum of Art in New York City. At its height in A.D. 850, the caliphate ruled parts of Northern Africa and much of the Middle East. The caliphate fell when the Mongols sacked Baghdad in 1258.
"Finding gold coins, certainly in such a considerable quantity, is extremely rare," Liat Nadav-Ziv and Elie Haddad, who directed the IAA excavation, said in the statement. "We almost never find them in archeological excavations, given that gold has always been extremely valuable, melted down and reused from generation to generation."
The coins are in "excellent condition, as if buried the day before," because they were made of pure gold, meaning that they won't oxidize when exposed to air, Nadav-Ziv and Haddad added.
Image 1 of 12 The remnants of the jar that held the coins for about 1,100 years. (Image credit: Yoli Schwartz/Israel Antiquities Authority) Liat Nadav-Ziv, director of the excavation, holds a gold coin. (Image credit: Yoli Schwartz/Israel Antiquities Authority) The pieces of gold dinar that were cut to be used as "small change". (Image credit: Robert Kool/Israel Antiquities Authority) The rare Byzantine coin fragment depicting Emperor Theophilos. (Image credit: Robert Kool/Israel Antiquities Authority) Shahar Krispin, Israel Antiquities Authority coin expert, counts the gold coins during the excavation. (Image credit: Yoli Schwartz/Israel Antiquities Authority) The pile of gold coins that were found in a buried clay jar. (Image credit: Yoli Schwartz/Israel Antiquities Authority) There were 425 gold coins in total. (Image credit: Yoli Schwartz/Israel Antiquities Authority) Liat Nadav-Ziv puts the pure gold coins in a plastic bag. (Image credit: Yoli Schwartz/Israel Antiquities Authority) Liat Nadav-Ziv collects the coins for a later analysis. (Image credit: Yoli Schwartz/Israel Antiquities Authority) The nail that secured the jar to the ground when it was buried. (Image credit: Yoli Schwartz/Israel Antiquities Authority) Shahar Krispin examines and counts the coins. (Image credit: Yoli Schwartz/Israel Antiquities Authority) The excavation site (Image credit: Emil Aladjem/Israel Antiquities Authority)
The 1.8-lbs. (845 grams) hoard was "a significant amount of money in those days," Robert Kool, a coin expert at the IAA said in the statement. "For example, with such a sum, a person could buy a luxurious house in one of the best neighborhoods in Fustat, the enormous wealthy capital of Egypt in those days." (Today, based on the current price of gold per gram, that pot of gold would be worth approximately $52,600.)
The hoard is one of the earliest known gold caches from the end of the ninth century in what is now Israel, Kool noted. The stash includes full gold dinars and about 270 small gold cuttings, "pieces of gold dinars cut to serve as 'small change,' a regular practice in Islamic countries after the 850s, when bronze and copper coins fell out of use."
One of the cuttings is an exceptional artifact that has never been found before in Israel. This particular piece is a fragment of a gold solidus, a nearly pure gold coin, depicting the Byzantine emperor Theophilos (A.D. 829 – 842), and minted in the empire’s capital of Constantinople. Its presence in the hoard of Islamic coins is evidence of monetary connections, perhaps a sign of trade, between the two rival empires from this period.
"This rare treasure will certainly be a major contribution to research, as finds from the Abbasid period in Israel are relatively few," Kool said. "Hopefully the study of the hoard will tell us more about a period of which we still know very little."
Editor's Note: This story was updated to fix a numerical conversion. The gold stash weighed 1.8 lbs. (845 grams). Additionally, the spelling of carat was changed to karat.
Originally published on Live Science.