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🦖 Last day of the dinosaurs' reign captured in stunning detail
« on: September 10, 2019, 02:20:58 PM »
https://www.nationalgeographic.com/science/2019/09/last-day-dinosaurs-reign-captured-stunning-detail/


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In an instant, the Chicxulub impact forever changed life on Earth—blasting out a huge crater, vaporizing and flinging up tons of rock, and devastating plant and animal life.

Science & Innovation
Last day of the dinosaurs' reign captured in stunning detail
Rocks from deep inside the Chicxulub impact crater show what happened in the minutes to hours after one of our planet’s most catastrophic events.
5 Minute Read
By Maya Wei-Haas

PUBLISHED September 9, 2019

Inch by inch, the team pulled up the skinny core of ghostly white limestone from the ocean floor, gazing at the compressed remains of ancient organisms that died tens of millions of years ago. But then a stark divide appeared as the layers abruptly darkened.

“It was nothing like the stuff above,” recalls Sean Gulick, a co-chief scientist of the expedition and a researcher at the University of Texas at Austin.

This change in the rock marks one of the most catastrophic events in Earth’s history, some 66 million years ago, when an epic asteroid slammed into the sea just offshore of Mexico’s Yucatán Peninsula. The impact triggered a nightmarish sequence of events that sent some 75 percent of plant and animal species spiraling to extinction—including all the nonavian dinosaurs.

Now, by subjecting the rocky core to a battery of tests, including geochemical study and x-ray imaging, the research team has assembled a meticulous timeline chronicling events on that fateful day—sometimes down to the minute. As they report today in the Proceedings of the National Academy of Sciences, the dark layers reveal stunning details, including the sheer amount of material that piled up mere hours after the strike, along with bits of charcoal later left by raging wildfires.

“They can put their fingers on moments in that event,” says Jennifer Anderson, an experimental geologist who studies impact cratering at Winona State University. “The level of detail kind of blows you away.”
 
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Earth 101 Earth is the only planet known to maintain life. Find out the origins of our home planet and some of the key ingredients that help make this blue speck in space a unique global ecosystem.

While it’s unlikely another asteroid smashup of this magnitude will happen in our lifetimes, significant impacts are inevitable in the larger arc of our planet’s evolution, says Purdue University’s Jay Melosh, who is not part of the study team but who worked on other sections of the crater core. Studying these events helps us more strongly grasp the vulnerabilities of life on Earth, he says.

“It’s not a matter of whether there will be big impacts,” he says, “it’s just a matter of when.”
Drilling into disaster

Previous studies have been slowly piecing together what happened after the so-called Chicxulub impact using a combination of computer models and the geologic fallout found at a smattering of sites around the world. One controversial locale in North Dakota may even capture an entire ecosystem catastrophically tossed by the seismic waves that rippled out from the impact zone.

But the exact details of the chaos that ensued have been an enduring mystery, one that scientists hoped to solve by closely examining the impact crater itself. Layers of sediment had buried the crater over millennia, which prevented roaring winds and water from wearing it away, but also hid it out of reach of eager scientists. To actually touch this infamous moment in our planet’s history, researchers needed to drill.

Related: See asteroids and comets across the solar system
Photo: Comet glowing amid stars
Photo: Halley's comet
1/11
View Slideshow

Comet C/2001 Q4, also known as NEAT, emits a blue-and-purple glow as it moves through the cosmos in May 2004. Its coma, or head, and a portion of its tail are visible in this shot, as are myriad stars. This image was taken by telescope from Kitt Peak National Observatory near Tucson, Arizona.
Photograph courtesy T. Rector (University of Alaska Anchorage), Z. Levay and L. Frattare (Space Telescope Science Institute), and National Optical Astronomy Observatory/Association of Universities for Research in Astronomy/National Science Foundation

Of the thousands of known comets in the solar system, Halley's comet is one of some 200 that are periodic. Halley's comet orbits Earth every 76 years; the next flyby will occur in 2061.
Photograph by James Balog

This image shows ejected material that was propelled into space when NASA's Deep Impact probe collided with comet Tempel 1 at 1:52 a.m. ET on July 4, 2005. It was taken by the spacecraft's medium-resolution camera 16 seconds after impact.
Photograph courtesy NASA/JPL-Caltech/UMD

Seen here in a 2004 composite image, the intensely active surface of comet Wild 2 ejects dust and gas streams into space, leaving a trail millions of kilometers long. Other than the sun, Wild 2 is currently the most active planetary surface in our solar system, astronomers say.
Photograph courtesy NASA/JPL

The Hale-Bopp comet shines against a stellar backdrop in the constellation Sagittarius in this Hubble Space Telescope image. Discovered in 1995 by amateur astronomers Alan Hale in New… Read More
Photograph courtesy H. A. Weaver (Applied Research Corp.), P. D. Feldman (The Johns Hopkins University), and NASA

The round shape of Ceres, the largest object in the asteroid belt between Mars and Jupiter, suggests that its interior is layered like Earth's. First classified as an asteroid, Ceres was… Read More
Photograph courtesy NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI)
One of the youngest and best-preserved impact craters on Earth, Meteor Crater formed about 50,000 years ago when a 100-foot-wide (30-meter-wide) meteor weighing 100,000 tons slammed into the Arizona desert at an estimated 12 miles (20 kilometers) a second. The resulting explosion exceeded the combined force of today's nuclear arsenals and created a 0.7-mile-wide (1.1-kilometer-wide), 650-foot-deep (200-meter-deep) crater.
Photograph courtesy D. Roddy (U.S. Geological Survey), Lunar and Planetary Institute

This enlargement of a 1993 Hubble Space Telescope image shows the brightest nuclei in a string of approximately 20 objects that comprise Comet P/Shoemaker-Levy 9 as it hurtled… Read More
Photograph courtesy Dr. H. A. Weaver and Mr. T. E. Smith, STScI/NASA

Fragments of comet P/Shoemaker-Levy 9 struck Jupiter in July 1994, leaving the impacts visible in this ultraviolet image. The spots appear dark because of the large quantities of dust, which absorbs sunlight, being deposited in the planet's stratosphere.
Photograph courtesy Hubble Space Telescope Comet Team

Light reflects from the nucleus of the Tempel 1 comet in this Hubble Space Telescope image taken in 2005. The potato-shaped nucleus, which appears starlike because it's too small for Hubble to resolve, is 8.7 miles (14 kilometers) wide and 2.5 miles (4 kilometers) long.
Photograph courtesy NASA, ESA, P. Feldman (Johns Hopkins University) and H. Weaver (Johns Hopkins University Applied Physics Laboratory)

A new jet of dust streams from the icy nucleus of the Tempel 1 comet, caught in this Hubble Space Telescope image. The jet extends about 1,400 miles (2,200 kilometers)—roughly half… Read More
Photograph courtesy NASA, ESA, P. Feldman (Johns Hopkins University) and H. Weaver (Johns Hopkins University Applied Physics Laboratory)

Scientists started exploring the crater’s structure in 1996 via seismic surveys led by Joanna Morgan, who co-led the latest drilling efforts with Gulick. Along with a second expedition in 2005, that work confirmed the presence of what’s known as a peak ring—a circle of buried mountains that rapidly forms within the largest of impact craters. Such a structure is an ideal place to drill, Gulick says. Not only can it reveal the fundamental processes behind the formation of mega-craters, its elevation places it relatively close to the modern ocean floor, which means easier access.

In the spring of 2016, the team at last sunk metal teeth into the Chicxulub crater, and over the course of two months, they extracted sections of core 10 feet at a time. In total, they collected a slice of Earth about a half-mile long that captures the shocked rocks that were below the impact, layers of melted rock, and the transition back to normal seafloor sediments.

“It was amazing to be on the ship and see those cores first coming up and realize we had some really exciting things to say,” Gulick marvels.
Mounds of melted rock

The new study of that core sample combines the rocky record with computer models to create an unprecedented timeline of the geologic chaos on the day sparking the dinosaurs' demise.

“To say that we’re looking at something that happened the day the impact happened 66 million years ago, that’s a kind of resolution that we almost never see in geology,” Anderson says.
Today’sPopular Stories
Science & Innovation
Last day of the dinosaurs' reign captured in stunning detail
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Science & Innovation
New 'frozen dragon' pterosaur found hiding in plain sight

One of the most striking finds is the rate at which material was re-deposited after the impact. The asteroid strike excavated miles of ocean floor, vaporizing rock and water in a flash. A ripple of shockwaves inside the crater sent solid rock flowing like liquid to form a towering peak, which then collapsed outward to form the peak ring. Just tens of minutes later, a jumble of debris piled onto the peak ring in a layer some 130 feet thick. Some of this material came from a sheet of melted rock that splashed into place within minutes as the peak collapsed.

Then, as the ocean rushed back into the yawning molten gap, pockets of steam burst forth, flinging up more fragments of rock. Within an hour, the crater was likely covered in a churning vat of rocky oceanic soup, periodically sloshed by the collapse of the crater’s steep wall.

“Just like if you pour a bucket of water into a bathtub, it doesn’t sit quiet, it sloshes around,” Melosh explains. “Each slosh as it went back and forth deposited more material.”

Rocky bits slowly settled out from the stew, piling up hundreds of feet of more debris. In total, the event laid down nearly 430 feet of new material in a single day.
Sulfur surprise

The team also found a notable lack of sulfur in the crater’s rocks. About a third of the rocks surrounding Chicxulub are sulfur-rich minerals known as evaporites, but these minerals are conspicuously absent from the core sample the team drilled.

Instead, the impact seems to have vaporized the crater’s sulfur-bearing rocks, backing up past work that suggests the event released as much as 325 gigatons of sulfur. Yet the element’s near total absence hints that even this gargantuan number may be too low. This gas could have formed a haze of sulfuric acid that blotted out sunlight and triggered years of global cooling. Or, Melosh says, it might have created acid rain that abruptly acidified the oceans. Either way, the effects would have devastated life of all kinds.


    They can put their fingers on moments in that event ... The level of detail kind of blows you away.

Jennifer Anderson, Winona State University

What’s more, the rock core offers clues to how the collision instantly affected life on land. Hurtling to Earth at some 45,000 miles an hour, the impact likely sent out a flash of energy that ignited landscapes within a 900 miles radius.

“Mexico was on fire immediately,” Anderson says. The impact also flung geologic shrapnel high into the skies that plummeted back around the globe, igniting fires even farther from the impact zone. And in the top few inches of the core’s sediment, the scientists found bits of charcoal, likely created by those raging wildfires.

Intriguingly, the researchers also found biomarkers from the fungal breakdown of wood, which further suggests that these burned bits came from a landscape set ablaze. The team thinks a mighty tsunami rippled across the Gulf of Mexico—and perhaps around the world—and that the watery wall bounced back after crossing the Mexican highlands, dragging with it charred terrestrial remains.
Opening salvo

There are still many more questions to answer about how the impact and its aftermath rippled around the world, says Kirk Johnson, director of the Smithsonian National Museum of Natural History. But he praises the new work for providing such a stunningly preserved record of this terrifying day.

“In a way, it’s telling us things that we thought we knew, but it’s telling it with the data that underpins it for the first time,” Johnson says.

“I consider this to be an opening salvo,” adds the University of Washington’s Jody Bourgeois, who has studied the impact’s tsunami deposits in Texas and Mexico. Further study of the core samples and other evidence in the coming years will likely fill in many more details in the tumultuous tale.

“It’s heady,” Gulick says of finally publishing the first few papers from the drilling project. “The discoveries keep coming.”
« Last Edit: September 10, 2019, 02:23:00 PM by RE »
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Offline azozeo

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Re: 🦖 Last day of the dinosaurs' reign captured in stunning detail
« Reply #1 on: September 10, 2019, 04:04:37 PM »
https://www.nationalgeographic.com/science/2019/09/last-day-dinosaurs-reign-captured-stunning-detail/


<a href="http://www.youtube.com/v/bU1QPtOZQZU" target="_blank" class="new_win">http://www.youtube.com/v/bU1QPtOZQZU</a>
In an instant, the Chicxulub impact forever changed life on Earth—blasting out a huge crater, vaporizing and flinging up tons of rock, and devastating plant and animal life.

Science & Innovation
Last day of the dinosaurs' reign captured in stunning detail
Rocks from deep inside the Chicxulub impact crater show what happened in the minutes to hours after one of our planet’s most catastrophic events.
5 Minute Read
By Maya Wei-Haas

PUBLISHED September 9, 2019

Inch by inch, the team pulled up the skinny core of ghostly white limestone from the ocean floor, gazing at the compressed remains of ancient organisms that died tens of millions of years ago. But then a stark divide appeared as the layers abruptly darkened.

“It was nothing like the stuff above,” recalls Sean Gulick, a co-chief scientist of the expedition and a researcher at the University of Texas at Austin.

This change in the rock marks one of the most catastrophic events in Earth’s history, some 66 million years ago, when an epic asteroid slammed into the sea just offshore of Mexico’s Yucatán Peninsula. The impact triggered a nightmarish sequence of events that sent some 75 percent of plant and animal species spiraling to extinction—including all the nonavian dinosaurs.

Now, by subjecting the rocky core to a battery of tests, including geochemical study and x-ray imaging, the research team has assembled a meticulous timeline chronicling events on that fateful day—sometimes down to the minute. As they report today in the Proceedings of the National Academy of Sciences, the dark layers reveal stunning details, including the sheer amount of material that piled up mere hours after the strike, along with bits of charcoal later left by raging wildfires.

“They can put their fingers on moments in that event,” says Jennifer Anderson, an experimental geologist who studies impact cratering at Winona State University. “The level of detail kind of blows you away.”
 
Current Time 0:26
/
Duration 0:30
AD ENDS IN: 0:04
Earth 101 Earth is the only planet known to maintain life. Find out the origins of our home planet and some of the key ingredients that help make this blue speck in space a unique global ecosystem.

While it’s unlikely another asteroid smashup of this magnitude will happen in our lifetimes, significant impacts are inevitable in the larger arc of our planet’s evolution, says Purdue University’s Jay Melosh, who is not part of the study team but who worked on other sections of the crater core. Studying these events helps us more strongly grasp the vulnerabilities of life on Earth, he says.

“It’s not a matter of whether there will be big impacts,” he says, “it’s just a matter of when.”
Drilling into disaster

Previous studies have been slowly piecing together what happened after the so-called Chicxulub impact using a combination of computer models and the geologic fallout found at a smattering of sites around the world. One controversial locale in North Dakota may even capture an entire ecosystem catastrophically tossed by the seismic waves that rippled out from the impact zone.

But the exact details of the chaos that ensued have been an enduring mystery, one that scientists hoped to solve by closely examining the impact crater itself. Layers of sediment had buried the crater over millennia, which prevented roaring winds and water from wearing it away, but also hid it out of reach of eager scientists. To actually touch this infamous moment in our planet’s history, researchers needed to drill.

Related: See asteroids and comets across the solar system
Photo: Comet glowing amid stars
Photo: Halley's comet
1/11
View Slideshow

Comet C/2001 Q4, also known as NEAT, emits a blue-and-purple glow as it moves through the cosmos in May 2004. Its coma, or head, and a portion of its tail are visible in this shot, as are myriad stars. This image was taken by telescope from Kitt Peak National Observatory near Tucson, Arizona.
Photograph courtesy T. Rector (University of Alaska Anchorage), Z. Levay and L. Frattare (Space Telescope Science Institute), and National Optical Astronomy Observatory/Association of Universities for Research in Astronomy/National Science Foundation

Of the thousands of known comets in the solar system, Halley's comet is one of some 200 that are periodic. Halley's comet orbits Earth every 76 years; the next flyby will occur in 2061.
Photograph by James Balog

This image shows ejected material that was propelled into space when NASA's Deep Impact probe collided with comet Tempel 1 at 1:52 a.m. ET on July 4, 2005. It was taken by the spacecraft's medium-resolution camera 16 seconds after impact.
Photograph courtesy NASA/JPL-Caltech/UMD

Seen here in a 2004 composite image, the intensely active surface of comet Wild 2 ejects dust and gas streams into space, leaving a trail millions of kilometers long. Other than the sun, Wild 2 is currently the most active planetary surface in our solar system, astronomers say.
Photograph courtesy NASA/JPL

The Hale-Bopp comet shines against a stellar backdrop in the constellation Sagittarius in this Hubble Space Telescope image. Discovered in 1995 by amateur astronomers Alan Hale in New… Read More
Photograph courtesy H. A. Weaver (Applied Research Corp.), P. D. Feldman (The Johns Hopkins University), and NASA

The round shape of Ceres, the largest object in the asteroid belt between Mars and Jupiter, suggests that its interior is layered like Earth's. First classified as an asteroid, Ceres was… Read More
Photograph courtesy NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI)
One of the youngest and best-preserved impact craters on Earth, Meteor Crater formed about 50,000 years ago when a 100-foot-wide (30-meter-wide) meteor weighing 100,000 tons slammed into the Arizona desert at an estimated 12 miles (20 kilometers) a second. The resulting explosion exceeded the combined force of today's nuclear arsenals and created a 0.7-mile-wide (1.1-kilometer-wide), 650-foot-deep (200-meter-deep) crater.
Photograph courtesy D. Roddy (U.S. Geological Survey), Lunar and Planetary Institute

This enlargement of a 1993 Hubble Space Telescope image shows the brightest nuclei in a string of approximately 20 objects that comprise Comet P/Shoemaker-Levy 9 as it hurtled… Read More
Photograph courtesy Dr. H. A. Weaver and Mr. T. E. Smith, STScI/NASA

Fragments of comet P/Shoemaker-Levy 9 struck Jupiter in July 1994, leaving the impacts visible in this ultraviolet image. The spots appear dark because of the large quantities of dust, which absorbs sunlight, being deposited in the planet's stratosphere.
Photograph courtesy Hubble Space Telescope Comet Team

Light reflects from the nucleus of the Tempel 1 comet in this Hubble Space Telescope image taken in 2005. The potato-shaped nucleus, which appears starlike because it's too small for Hubble to resolve, is 8.7 miles (14 kilometers) wide and 2.5 miles (4 kilometers) long.
Photograph courtesy NASA, ESA, P. Feldman (Johns Hopkins University) and H. Weaver (Johns Hopkins University Applied Physics Laboratory)

A new jet of dust streams from the icy nucleus of the Tempel 1 comet, caught in this Hubble Space Telescope image. The jet extends about 1,400 miles (2,200 kilometers)—roughly half… Read More
Photograph courtesy NASA, ESA, P. Feldman (Johns Hopkins University) and H. Weaver (Johns Hopkins University Applied Physics Laboratory)

Scientists started exploring the crater’s structure in 1996 via seismic surveys led by Joanna Morgan, who co-led the latest drilling efforts with Gulick. Along with a second expedition in 2005, that work confirmed the presence of what’s known as a peak ring—a circle of buried mountains that rapidly forms within the largest of impact craters. Such a structure is an ideal place to drill, Gulick says. Not only can it reveal the fundamental processes behind the formation of mega-craters, its elevation places it relatively close to the modern ocean floor, which means easier access.

In the spring of 2016, the team at last sunk metal teeth into the Chicxulub crater, and over the course of two months, they extracted sections of core 10 feet at a time. In total, they collected a slice of Earth about a half-mile long that captures the shocked rocks that were below the impact, layers of melted rock, and the transition back to normal seafloor sediments.

“It was amazing to be on the ship and see those cores first coming up and realize we had some really exciting things to say,” Gulick marvels.
Mounds of melted rock

The new study of that core sample combines the rocky record with computer models to create an unprecedented timeline of the geologic chaos on the day sparking the dinosaurs' demise.

“To say that we’re looking at something that happened the day the impact happened 66 million years ago, that’s a kind of resolution that we almost never see in geology,” Anderson says.
Today’sPopular Stories
Science & Innovation
Last day of the dinosaurs' reign captured in stunning detail
Travel
See 23 of the world’s most enchanting libraries
Science & Innovation
New 'frozen dragon' pterosaur found hiding in plain sight

One of the most striking finds is the rate at which material was re-deposited after the impact. The asteroid strike excavated miles of ocean floor, vaporizing rock and water in a flash. A ripple of shockwaves inside the crater sent solid rock flowing like liquid to form a towering peak, which then collapsed outward to form the peak ring. Just tens of minutes later, a jumble of debris piled onto the peak ring in a layer some 130 feet thick. Some of this material came from a sheet of melted rock that splashed into place within minutes as the peak collapsed.

Then, as the ocean rushed back into the yawning molten gap, pockets of steam burst forth, flinging up more fragments of rock. Within an hour, the crater was likely covered in a churning vat of rocky oceanic soup, periodically sloshed by the collapse of the crater’s steep wall.

“Just like if you pour a bucket of water into a bathtub, it doesn’t sit quiet, it sloshes around,” Melosh explains. “Each slosh as it went back and forth deposited more material.”

Rocky bits slowly settled out from the stew, piling up hundreds of feet of more debris. In total, the event laid down nearly 430 feet of new material in a single day.
Sulfur surprise

The team also found a notable lack of sulfur in the crater’s rocks. About a third of the rocks surrounding Chicxulub are sulfur-rich minerals known as evaporites, but these minerals are conspicuously absent from the core sample the team drilled.

Instead, the impact seems to have vaporized the crater’s sulfur-bearing rocks, backing up past work that suggests the event released as much as 325 gigatons of sulfur. Yet the element’s near total absence hints that even this gargantuan number may be too low. This gas could have formed a haze of sulfuric acid that blotted out sunlight and triggered years of global cooling. Or, Melosh says, it might have created acid rain that abruptly acidified the oceans. Either way, the effects would have devastated life of all kinds.


    They can put their fingers on moments in that event ... The level of detail kind of blows you away.

Jennifer Anderson, Winona State University

What’s more, the rock core offers clues to how the collision instantly affected life on land. Hurtling to Earth at some 45,000 miles an hour, the impact likely sent out a flash of energy that ignited landscapes within a 900 miles radius.

“Mexico was on fire immediately,” Anderson says. The impact also flung geologic shrapnel high into the skies that plummeted back around the globe, igniting fires even farther from the impact zone. And in the top few inches of the core’s sediment, the scientists found bits of charcoal, likely created by those raging wildfires.

Intriguingly, the researchers also found biomarkers from the fungal breakdown of wood, which further suggests that these burned bits came from a landscape set ablaze. The team thinks a mighty tsunami rippled across the Gulf of Mexico—and perhaps around the world—and that the watery wall bounced back after crossing the Mexican highlands, dragging with it charred terrestrial remains.
Opening salvo

There are still many more questions to answer about how the impact and its aftermath rippled around the world, says Kirk Johnson, director of the Smithsonian National Museum of Natural History. But he praises the new work for providing such a stunningly preserved record of this terrifying day.

“In a way, it’s telling us things that we thought we knew, but it’s telling it with the data that underpins it for the first time,” Johnson says.

“I consider this to be an opening salvo,” adds the University of Washington’s Jody Bourgeois, who has studied the impact’s tsunami deposits in Texas and Mexico. Further study of the core samples and other evidence in the coming years will likely fill in many more details in the tumultuous tale.

“It’s heady,” Gulick says of finally publishing the first few papers from the drilling project. “The discoveries keep coming.”


Love the vid.

Nice depiction of a cosmic shit storm....
I know exactly what you mean. Let me tell you why you’re here. You’re here because you know something. What you know you can’t explain, but you feel it. You’ve felt it your entire life, that there’s something wrong with the world.
You don’t know what it is but its there, like a splinter in your mind

Offline RE

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Re: 🦖 Last day of the dinosaurs' reign captured in stunning detail
« Reply #2 on: September 10, 2019, 05:04:23 PM »

Love the vid.

Nice depiction of a cosmic shit storm....

One of my favorites.  :icon_sunny:

Extinction will come, one way or the other.  The only open question is when and by what vector.

RE
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Offline azozeo

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Re: 🦖 Last day of the dinosaurs' reign captured in stunning detail
« Reply #3 on: September 10, 2019, 05:57:10 PM »

Love the vid.

Nice depiction of a cosmic shit storm....

One of my favorites.  :icon_sunny:

Extinction will come, one way or the other.  The only open question is when and by what vector.

RE

Companion article just flew into my radar.

Great Mud Flooder  :coffee:

https://sputniknews.com/science/201909101076769319-dinosaur-killer-asteroid-earth-revealed/
I know exactly what you mean. Let me tell you why you’re here. You’re here because you know something. What you know you can’t explain, but you feel it. You’ve felt it your entire life, that there’s something wrong with the world.
You don’t know what it is but its there, like a splinter in your mind

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🦖 Groundbreaking fossils reveal how life retook Earth after the dinosaurs
« Reply #4 on: October 27, 2019, 01:11:03 AM »
The TARDIGRADES will RULE!

Encased in a Secret Chamber in the SUN Monument, I have Dessicated Tardigrades and my DNA (hair clippings).  10K years into the future, the DNA will recombine with the Tardigrade DNA to form a NEW SPECIESHomo Tardigradus Dinerus Sapiens that will Steward the Earth until the Sun goes Red Giant!  :icon_sunny:

1M years after that, we will figure out how to migrate to the 9th Dimension and travel through Interstellar Space at will.  :icon_sunny:  :o

RE's Descendants re-emerge from the Sun Monument in 12019 to Repopulate the Earth with Sapient Life

RE

https://www.slashgear.com/groundbreaking-fossils-reveal-how-life-retook-earth-after-the-dinosaurs-25597340/

Groundbreaking fossils reveal how life retook Earth after the dinosaurs
Chris Davies - Oct 25, 2019, 10:53 am CDT


An incredible fossil haul unearthed in Colorado could finally bridge the gap between the extinction of the dinosaurs and the reboot of life after that epoch-ending asteroid impact. Helping to answer questions which have long stumped scientists, the new findings pinpoint nature’s mysterious recovery immediately after three out of every four living organisms was suddenly killed.

That extinction event, when an asteroid crashed into Earth some 66 million years ago, was cataclysmic in terms of life on the planet. Not only did it mark the end of the dinosaurs, but huge swathes of other organisms, down to plants and more.

Fossil remains of dinosaurs and other vertebrates are now relatively commonplace, but details of what happened immediately after the asteroid strike have been in short supply. The path from mass extinction through to the rise of the mammals – and, eventually, human life – was uncertain. Now, though, a new cache of fossils could provide the answers for the million year period after the death of the dinosaurs.

Discovered by scientists from the Denver Museum of Nature & Science in Colorado, the fossil haul was first identified back in 2016. Dr. Tyler Lyson, curator of vertebrate paleontology at the museum and lead author on a new paper about the discovery in Science magazine, began hunting for egg-shaped rocks known as concretions.

These rocks are the compacted mass of matter, created when mineral cement forms between particles. While they form between layers of sedimentary strata, they’re typically created early on in the process, before the rest of that sediment has hardened. Because of that, they can capture a record of the time earlier than the overall strata might, while the concretionary cement can leave the rocks more resilient than what surrounds them.

As Dr Lyson and his team discovered, that has left each of the concretions a tiny, well-preserved time capsule. Working with Dr. Ian Miller, curator of paleobotany and director of earth and space sciences at the museum, they cracked open the concretions and found a huge wealth of fossilized remains.

“Inside were skulls of mammals from the early generations of survivors of the mass extinction,” the museum explains. “Finding even a single skull from this era is a coup. In fact, most of what is understood from this era is based on tiny fragments of fossils, such as pieces of mammal teeth.”

Instead, the researchers found more than a dozen skulls in the space of a week. Almost 1,000 vertebrate fossils have been recovered from the site, and overall fossils from at least 16 different species of mammal have been identified. They include brand new species, as well as forebears of animals like the modern-day pig.

Combined with fossil plant records, it’s a new window onto a little-understood period in the Earth’s development. “Our understanding of the asteroid’s aftermath has been spotty,” Lyson says. “These fossils tell us for the first time how exactly our planet recovered from this global cataclysm.”

The findings are the topic of a new PBS series, Rise of the Mammals, which will air later this month.
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🦖 Research unravels mystery of how early animals survived ice age
« Reply #5 on: December 03, 2019, 12:24:01 AM »
https://phys.org/news/2019-12-unravels-mystery-early-animals-survived.html

December 2, 2019
Research unravels mystery of how early animals survived ice age

by McGill University


Credit: CC0 Public Domain

How did life survive the most severe ice age? A McGill University-led research team has found the first direct evidence that glacial meltwater provided a crucial lifeline to eukaryotes during Snowball Earth, when the oceans were cut off from life-giving oxygen, answering a question puzzling scientists for years.

In a new study published in the Proceedings of the National Academy of Sciences of the United States of America, researchers studied iron-rich rocks left behind by glacial deposits in Australia, Namibia, and California to get a window into the environmental conditions during the ice age. Using geological maps and clues from locals, they hiked to rock outcrops, navigating challenging trails to track down the rock formations.

By examining the chemistry of the iron formations in these rocks, the researchers were able to estimate the amount of oxygen in the oceans around 700 million years ago and better understand the effects this would have had on all oxygen-dependent marine life, including the earliest animals like simple sponges.

"The evidence suggests that although much of the oceans during the deep freeze would have been uninhabitable due to a lack of oxygen, in areas where the grounded ice sheet begins to float there was a critical supply of oxygenated meltwater. This trend can be explained by what we call a 'glacial oxygen pump'; air bubbles trapped in the glacial ice are released into the water as it melts, enriching it with oxygen," says Maxwell Lechte, a postdoctoral researcher in the Department of Earth and Planetary Sciences under the supervision of Galen Halverson at McGill University.

Around 700 million years ago, the Earth experienced the most severe ice age of its history, threatening the survival of much of the planet's life. Previous research has suggested that oxygen-dependent life may have been restricted to meltwater puddles on the surface of the ice, but this study provides new evidence of oxygenated marine environments.

"The fact that the global freeze occurred before the evolution of complex animals suggests a link between Snowball Earth and animal evolution. These harsh conditions could have stimulated their diversification into more complex forms," says Lechte, who is also the study's lead author.

Lechte points out that while the findings focus on the availability of oxygen, primitive eukaryotes would also have needed food to survive the harsh conditions of the ice age. Further research is needed to explore how these environments might have sustained a food web. A starting point might be modern ice environments that host complex ecosystems today.

"This study actually solves two mysteries about the Snowball Earth at once. It not only provides explanation for how early animals may have survived global glaciation, but also eloquently explains the return of iron deposits in the geological record after an absence of over a billion years," says Professor Galen Halverson.

"Subglacial meltwater supported aerobic marine habitats during Snowball Earth" by Maxwell Lechte, Malcolm Wallace, Ashleigh van Smeerdijk Hood, Weiqiang Li, Ganqing Jiang, Galen Halverson, Dan Asael, Stephanie McColl, and Noah Planavsky is published in Proceedings of the National Academy of Sciences of the United States of America.
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🦖 A lost world and extinct ecosystem
« Reply #6 on: May 15, 2020, 02:21:48 AM »
https://phys.org/news/2020-05-lost-world-extinct-ecosystem.html

May 14, 2020
A lost world and extinct ecosystem

by Arizona State University

Looking out at the Palaeo-Agulhas Plain from the cave entrance at the Pinnacle Point, South Africa, research site--left, 200,000 years ago during glacial phases and lower sea levels, and right, today where the ocean is within yards of the cave entrances at high tides. Credit: Erich Fisher

Archaeological sites on the far southern shores of South Africa hold the world's richest records for the behavioral and cultural origins of our species. At this location, scientists have discovered the earliest evidence for symbolic behavior, complex pyrotechnology, projectile weapons and the first use of foods from the sea.

The Arizona State University Institute of Human Origins (IHO) field study site of Pinnacle Point sits at the center of this record, both geographically and scientifically, having contributed much of the evidence for these milestones on the evolutionary road to being a modern human.

The scientists working on these sites, led by IHO Associate Director Curtis Marean, have always faced a dilemma in understanding the context of these evolutionary milestones—much of the landscape used by these ancient people is now submerged undersea and thus poorly known to us. Marean is a Foundation Professor with the ASU School of Human Evolution and Social Change and Honorary Professor with Nelson Mandela University in South Africa.

The archaeological records come from caves and rockshelters that now look out on to the sea, and in fact, walking to many of the sites today involves dodging high tides and waves. However, through most of the last 200,000 years, lowered sea levels during glacial phases, when the ice sucks up the water, exposed a vast plain. The coast was sometimes as much as 90 km distant! Our archaeological data shows that this was the prime foraging habitat for these early modern humans, and until recently, we knew nothing about.

That has now changed with the publication of 22 articles in a special issue of Quaternary Science Reviews titled "The Palaeo-Agulhas Plain: A lost world and extinct ecosystem." About ten years ago, Marean began building a transdisciplinary international team to tackle the problem of building an ecology of this ancient landscape. ASU, Nelson Mandela University, the University of Cape Town, and the University of California at Riverside anchored the research team. Funded primarily by a $1 million National Science Foundation grant to Marean, with significant funding and resources from the Hyde Family Foundations, the John Templeton Foundation, ASU, IHO, and XSEDE, they developed an entirely new way to reconstruct "paleoecologies" or ancient ecosystems.

This began with using the high-resolution South African regional climate model—running on U.S. and South African supercomputers—to simulate glacial climate conditions. The researchers used this climate output to drive a new vegetation model developed by project scientists to recreate the vegetation on this paleoscape. They then used a wide variety of studies such as marine geophysics, deep-water diving for sample collection, isotopic studies of stalagmites and many other transdisciplinary avenues of research to validate and adjust this model output. They also created a human "agent-based model" through modern studies of human foraging of plants, animals, and seafoods, simulating how ancient people lived on this now extinct paleoscape.

"Pulling the threads of all this research into one special issue illustrates all of this science," said Curtis Marean. "It represents a unique example of a truly transdisciplinary paleoscience effort, and a new model for going forward with our search to recreate the nature of past ecosystems. Importantly, our results help us understand why the archaeological records from these South African sites consistently reveal early and complex levels of human behavior and culture. The Palaeo-Agulhas Plain, when exposed, was a 'Serengeti of the South"' positioned next to some of the richest coastlines in the world. This unique confluence of food from the land and sea cultivated the complex cultures revealed by the archaeology and provided safe harbor for humans during the glacial cycles that revealed that plain and made much of the rest of the world unwelcoming to human life."
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