Oldest Scorpion Fossil Discovered

<div dir="ltr" style="text-align: left;" trbidi="on"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://1.bp.blogspot.com/-Iu9e7yQxbVA/XiY89A0Vg1I/AAAAAAAAR3Q/IMYoGNtuxy4kGeek-v-z0OiwiBBI1kcQwCLcBGAsYHQ/s1600/Oldest%2BScorpion%2BFossil%2BDiscovered%2B%25281%2529.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="938" data-original-width="1200" height="312" src="https://1.bp.blogspot.com/-Iu9e7yQxbVA/XiY89A0Vg1I/AAAAAAAAR3Q/IMYoGNtuxy4kGeek-v-z0OiwiBBI1kcQwCLcBGAsYHQ/s400/Oldest%2BScorpion%2BFossil%2BDiscovered%2B%25281%2529.jpg" width="400" /></a></div> <br /> <br /> <span style="font-family: "georgia" , "times new roman" , serif;">Scientists have revealed the oldest known scorpion—and arachnid—on Earth: a mysterious species more than 430 million years old uncovered near Waukesha, Wisconsin, about 29 kilometers west of Milwaukee.</span><br /> <br /> Scientists studying fossils collected 35 years ago have identified them as the oldest-known scorpion species, a prehistoric animal from about 437 million years ago. The researchers found that the animal likely had the capacity to breathe in both ancient oceans and on land.<br /> <br /> The discovery provides new information about how animals transitioned from living in the sea to living entirely on land: The scorpion's respiratory and circulatory systems are almost identical to those of our modern-day scorpions -- which spend their lives exclusively on land -- and operate similarly to those of a horseshoe crab, which lives mostly in the water, but which is capable of forays onto land for short periods of time.<br /> <br /> The researchers named the new scorpion Parioscorpio venator. The genus name means "progenitor scorpion," and the species name means "hunter." They outlined their findings in a study published today in the journal Scientific Reports.<br /> <br /> "We're looking at the oldest known scorpion -- the oldest known member of the arachnid lineage, which has been one of the most successful land-going creatures in all of Earth history," said Loren Babcock, an author of the study and a professor of earth sciences at The Ohio State University.<br /> <br /> "And beyond that, what is of even greater significance is that we've identified a mechanism by which animals made that critical transition from a marine habitat to a terrestrial habitat. It provides a model for other kinds of animals that have made that transition including, potentially, vertebrate animals. It's a groundbreaking discovery."<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> The "hunter scorpion" fossils were unearthed in 1985 from a site in Wisconsin that was once a small pool at the base of an island cliff face. They had remained unstudied in a museum at the University of Wisconsin for more than 30 years when one of Babcock's doctoral students, Andrew Wendruff -- now an adjunct professor at Otterbein University in Westerville -- decided to examine the fossils in detail.<br /> <br /> Wendruff and Babcock knew almost immediately that the fossils were scorpions. But, initially, they were not sure how close these fossils were to the roots of arachnid evolutionary history. The earliest known scorpion to that point had been found in Scotland and dated to about 434 million years ago. Scorpions, paleontologists knew, were one of the first animals to live on land full-time.<br /> <br /> The Wisconsin fossils, the researchers ultimately determined, are between 1 million and 3 million years older than the fossil from Scotland. They figured out how old this scorpion was from other fossils in the same formation. Those fossils came from creatures that scientists think lived between 436.5 and 437.5 million years ago, during the early part of the Silurian period, the third period in the Paleozoic era.<br /> <br /> "People often think we use carbon dating to determine the age of fossils, but that doesn't work for something this old," Wendruff said. "But we date things with ash beds -- and when we don't have volcanic ash beds, we use these microfossils and correlate the years when those creatures were on Earth. It's a little bit of comparative dating."<br /> <br /> The Wisconsin fossils -- from a formation that contains fossils known as the Waukesha Biota -- show features typical of a scorpion, but detailed analysis showed some characteristics that were not previously known in any scorpion, such as additional body segments and a short "tail" region, all of which shed light on the ancestry of this group.<br /> <br /> Wendruff examined the fossils under a microscope, and took detailed, high-resolution photographs of the fossils from different angles. Bits of the animal's internal organs, preserved in the rock, began to emerge. He identified the appendages, a chamber where the animal would have stored its venom, and -- most importantly -- the remains of its respiratory and circulatory systems.<br /> <br /> This scorpion is about 2.5 centimeters long -- about the same size as many scorpions in the world today. And, Babcock said, it shows a crucial evolutionary link between the way ancient ancestors of scorpions respired under water, and the way modern-day scorpions breathe on land. Internally, the respiratory-circulatory system has a structure just like that found in today's scorpions.<br /> <br /> "The inner workings of the respiratory-circulatory system in this animal are, shape-wise, identical to those of the arachnids and scorpions that breathe air exclusively," Babcock said. "But it also is incredibly similar to what we recognize in marine arthropods like horseshoe crabs. So, it looks like this scorpion, this lineage, must have been pre-adapted to life on land, meaning they had the morphologic capability to make that transition, even before they first stepped onto land."<br /> <br /> Paleontologists have for years debated how animals moved from sea to land. Some fossils show walking traces in the sand that may be as old as 560 million years, but these traces may have been made in prehistoric surf -- meaning it is difficult to know whether animals were living on land or darting out from their homes in the ancient ocean.<br /> <br /> But with these prehistoric scorpions, Wendruff said, there was little doubt that they could survive on land because of the similarities to modern-day scorpions in the respiratory and circulatory systems.<br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://news.osu.edu/fossil-is-the-oldest-known-scorpion/" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.osu.edu/" rel="nofollow" target="_blank">Ohio State University</a>. Original written by Laura Arenschield.</span></i></u></div>

Oldest Scorpion Fossil Discovered

Scientists have revealed the oldest known scorpion—and arachnid—on Earth: a mysterious species more than 430 million years old uncovere...

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World's Oldest Slime Mold Found in Amber

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-1isyYgCTagM/XiXlJi6OjXI/AAAAAAAAR3E/I-3OgG6XQBQdZpjTvKFcKB3-Wce2jUebACLcBGAsYHQ/s1600/100millidddonye%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="World's Oldest Slime Mold Found in Amber" border="0" data-original-height="857" data-original-width="1195" height="458" src="https://1.bp.blogspot.com/-1isyYgCTagM/XiXlJi6OjXI/AAAAAAAAR3E/I-3OgG6XQBQdZpjTvKFcKB3-Wce2jUebACLcBGAsYHQ/s640/100millidddonye%2B%25281%2529.jpg" title="" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">100 million-year-old amber piece with lizard leg and mycomycete (arrow). Credit: Alexander Schmidt, University of Göttingen and Scientific Reports</td></tr> </tbody></table> <br /> <h4 style="text-align: left;"> <span style="font-family: "georgia" , "times new roman" , serif;">100 million years in amber: Researchers discover oldest fossilized slime mold</span></h4> <span style="font-family: "georgia" , "times new roman" , serif;">Researchers have discovered a 100-million-year-old slime mold and a lizard leg perfectly preserved in amber from a tree in Myanmar, a find described as “unique.”</span><br /> <br /> Most people associate the idea of creatures trapped in amber with insects or spiders, which are preserved lifelike in fossil tree resin. An international research team of palaeontologists and biologists from the Universities of Göttingen and Helsinki, and the American Museum of Natural History in New York has now discovered the oldest slime mould identified to date. The fossil is about 100 million years old and is exquisitely preserved in amber from Myanmar. The results have been published in the journal Scientific Reports.<br /> <br /> Slime moulds, also called myxomycetes, belong to a group known as 'Amoebozoa'. These are microscopic organisms that live most of the time as single mobile cells hidden in the soil or in rotting wood, where they eat bacteria. However, they can join together to form complex, beautiful and delicate fruiting bodies, which serve to make and spread spores.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Since fossil slime moulds are extremely rare, studying their evolutionary history has been very difficult. So far, there have only been two confirmed reports of fossils of fruiting bodies and these are just 35 to 40 million years old.<br /> <br /> The discovery of fossil myxomycetes is very unlikely because their fruiting bodies are extremely short-lived. The researchers are therefore astounded by the chain of events that must have led to the preservation of this newly identified fossil.<br /> <br /> "The fragile fruiting bodies were most likely torn from the tree bark by a lizard, which was also caught in the sticky tree resin, and finally embedded in it together with the reptile," says Professor Jouko Rikkinen from the University of Helsinki.<br /> <br /> The lizard detached the fruiting bodies at a relatively early stage when the spores had not yet been released, which now reveals valuable information about the evolutionary history of these fascinating organisms.<br /> <br /> The researchers were surprised by the discovery that the slime mould can easily be assigned to a genus still living today. "The fossil provides unique insights into the longevity of the ecological adaptations of myxomycetes," explains palaeontologist Professor Alexander Schmidt from the University of Göttingen, lead author of the study.<br /> <br /> "We interpret this as evidence of strong environmental selection. It seems that slime moulds that spread very small spores using the wind had an advantage," says Rikkinen. The ability of slime moulds to develop long-lasting resting stages in their life cycle, which can last for years, probably also contributes to the remarkable similarity of the fossil to its closest present-day relatives.<br /> <br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.uni-goettingen.de/en/3240.html?id=5769" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.uni-goettingen.de/" rel="nofollow" target="_blank">University of Göttingen</a>.</span></i></u></div>

World's Oldest Slime Mold Found in Amber

100 million-year-old amber piece with lizard leg and mycomycete (arrow). Credit: Alexander Schmidt, University of Göttingen and Scientifi...

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Dinosaurs Were Killed by Asteroid and Not Volcanoes, Scientists Confirm

<div dir="ltr" style="text-align: left;" trbidi="on"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://1.bp.blogspot.com/-OLPkRR6hQEs/XiOj4Sn5_1I/AAAAAAAAR2M/pR-FuTR0xd8CGo8wSM-P9UUb3eOLwlN_QCLcBGAsYHQ/s1600/Dinosaurs%2BWere%2BKilled%2Bby%2BAsteroid%2Band%2BNot%2BVolcanoes%252C%2BScientists%2BConfirm.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="803" data-original-width="1204" height="426" src="https://1.bp.blogspot.com/-OLPkRR6hQEs/XiOj4Sn5_1I/AAAAAAAAR2M/pR-FuTR0xd8CGo8wSM-P9UUb3eOLwlN_QCLcBGAsYHQ/s640/Dinosaurs%2BWere%2BKilled%2Bby%2BAsteroid%2Band%2BNot%2BVolcanoes%252C%2BScientists%2BConfirm.jpg" width="640" /></a></div> <br /> <br /> <span style="font-family: "georgia" , "times new roman" , serif;">Mass Extinction That Killed the Dinosaurs Was All About the Asteroid – Not Volcanoes</span><br /> <br /> Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.<br /> <br /> In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from massive volcanic eruptions in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene extinction event 66 million years ago and therefore did not contribute to the mass extinction.<br /> <br /> Most scientists acknowledge that the mass extinction event, also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that volcanic activity happened around the same time.<br /> <br /> "Volcanoes can drive mass extinctions because they release lots of gases, like SO₂ and CO₂, that can alter the climate and acidify the world," said Hull, lead author of the new study. "But recent work has focused on the timing of lava eruption rather than gas release."<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared global temperature change and the carbon isotopes (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact -- and that the asteroid was the sole driver of extinction.<br /> <br /> "Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction," said former Yale researcher Michael Henehan, who compiled the temperature records for the study. "A number of species moved toward the North and South poles but moved back well before the asteroid impact."<br /> <br /> Added Hull, "A lot of people have speculated that volcanoes mattered to K-Pg, and we're saying, 'No, they didn't.'"<br /> <br /> Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.<br /> <br /> "The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle," said Yale postdoctoral associate Donald Penman, the study's modeler. "Our results show that these changes would allow the ocean to absorb an enormous amount of CO₂ on long time scales -- perhaps hiding the warming effects of volcanism in the aftermath of the event."<br /> <br /> The International Ocean Discovery Program, the National Science Foundation, and Yale University helped fund the research.<br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;"> The above story is based on <a href="https://news.yale.edu/2020/01/16/death-dinosaurs-it-was-all-about-asteroid-not-volcanoes" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.yale.edu/" rel="nofollow" target="_blank">Yale University</a>. Original written by Jim Shelton.</span></i></u></div>

Dinosaurs Were Killed by Asteroid and Not Volcanoes, Scientists Confirm

Mass Extinction That Killed the Dinosaurs Was All About the Asteroid – Not Volcanoes Volcanic activity did not play a direct role in ...

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How Nodules Stay on Top at the Bottom of the Sea

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-vmt2c90R0iw/Xh54aS9XkMI/AAAAAAAARzo/9aoYoVRL0qA1NtASpEh9cggWLodmzhMewCLcBGAsYHQ/s1600/How%2BNodules%2BStay%2Bon%2BTop%2Bat%2Bthe%2BBottom%2Bof%2Bthe%2BSea%2B%25282%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="750" data-original-width="1000" height="480" src="https://1.bp.blogspot.com/-vmt2c90R0iw/Xh54aS9XkMI/AAAAAAAARzo/9aoYoVRL0qA1NtASpEh9cggWLodmzhMewCLcBGAsYHQ/s640/How%2BNodules%2BStay%2Bon%2BTop%2Bat%2Bthe%2BBottom%2Bof%2Bthe%2BSea%2B%25282%2529.jpg" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">Photo credit: Utah Geological Survey</td></tr> </tbody></table> <br /> <br /> <div style="text-align: left;"> <span style="font-family: "georgia" , "times new roman" , serif;">Rare metallic elements found in clumps on the deep-ocean floor mysteriously remain uncovered despite the shifting sands and sediment many leagues under the sea. Scientists now think they know why, and it could have important implications for mining these metals while preserving the strange fauna at the bottom of the ocean.</span><br /> <br /> The growth of these deep-sea nodules -- metallic lumps of manganese, iron, and other metals found in all the major ocean basins -- is one of the slowest known geological processes. These ringed concretions, which are potential sources of rare-earth and other critical elements, grow on average just 10 to 20 millimeters every million years. Yet in one of earth science's most enduring mysteries, they somehow manage to avoid being buried by sediment despite their locations in areas where clay accumulates at least 100 times faster than the nodules grow.<br /> <br /> Understanding how these agglomerations of metals remain on the open sea floor could help geoscientists provide advice on accessing them for industrial use. A new study published this month in Geology will help scientists understand this process better.<br /> <br /> "It is important that any mining of these resources is done in a way that preserves the fragile deep-sea environments in which they are found," said lead author Adriana Dutkiewicz, an ARC Future Fellow in the School of Geosciences at The University of Sydney.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Rare-earth and other critical elements are essential for the development of technologies needed for low-carbon economies. They will play an increasingly important role for next-generation solar cells, efficient wind turbines, and rechargeable batteries that will power the renewables revolution.</div> <h4 style="text-align: left;"> <span style="font-family: "georgia" , "times new roman" , serif;">Solving the Enigma</span></h4> <div style="text-align: left;"> From scouring bottom currents to burrowing animals, researchers have proposed a number of mechanisms to account for this enigma. But solving it depends on a better understanding of where the nodules are situated and the environmental conditions that prevail there. Now a global study published in Geology uses predictive machine learning to investigate which factors control the location of polymetallic nodules. The results offer new insights to inform deep-sea mineral exploration as well as its regulation.<br /> <br /> "The International Seabed Authority is currently preparing new environmental regulations to govern deep-sea mining," Dr. Dutkiewicz said. "Our analysis represents a global, data-driven synthesis to impartially inform these policies and deep-ocean environmental management."<br /> <br /> Dr. Dutkiewicz and co-authors Dr. Alexander Judge and Professor Dietmar Müller combined open-access data for thousands of polymetallic nodules with global datasets of key environmental parameters to create a machine-learning model that ranks the factors controlling nodule location. The resulting map predicts where polymetallic nodules are most likely to occur.<br /> <br /> The authors were surprised to find that globally the nodules occur in regions where the bottom current speeds are far too slow to remove sediment. Instead, the nodules are associated with seafloor fauna.<br /> <br /> "Organisms such as star fish, octopods and molluscs seem to keep the nodules at the seafloor surface by foraging, burrowing and ingesting sediment on and around them," Dr. Dutkiewicz said. "Although these organisms occur in relatively low concentrations on the abyssal seafloor, they are still abundant enough to locally affect sediment accumulation."<br /> <br /> This insight is supported by direct seafloor observations of nodule fields by independent studies. "Our conclusion is that deep-sea ecosystems and nodules are inextricably connected," Dr. Dutkiewicz said.<br /> <br /> The study results also suggest that the regions where nodules are most likely to occur are more extensive than what has previously been assumed and include vast areas that are yet to be explored -- findings with important industrial as well as conservation implications.<br /> <br /> "Our map highlights regions that may be important economically," Dr. Dutkiewicz said, "but at the same time draws attention to areas of the seafloor that may be hotspots for diverse deep-sea organisms that we know little about."<br /> <br /> Because the techniques used by the researchers can be modified to investigate other seafloor features, this approach -- as well as the conclusion that there is an apparent "symbiosis" between deep-sea fauna and the nodules -- could also have implications for future biodiversity research.<br /> <br /> "Vast regions of the deep sea are unexplored," Dr. Dutkiewicz said, "so the consequences of nodule mining for deep-sea ecosystems need to be carefully evaluated."</div> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.geosociety.org/GSA/News/pr/2020/20-02.aspx" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.geosociety.org/" rel="nofollow" target="_blank">Geological Society of America</a>.</span></i></u></div>

How Nodules Stay on Top at the Bottom of the Sea

Photo credit: Utah Geological Survey Rare metallic elements found in clumps on the deep-ocean floor mysteriously remain uncovered de...

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7 Billion-Year-Old Stardust Is Oldest Material Found on Earth

<div dir="ltr" style="text-align: left;" trbidi="on"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://1.bp.blogspot.com/-M3vhjfvCNqE/Xh0fy4OlXbI/AAAAAAAARzc/usz34MYZpfg3ozdozbowB7DPDL4o0xxYACLcBGAsYHQ/s1600/7%2BBillion-Year-Old%2BStardust%2BIs%2BOldest%2BMaterial%2BFound%2Bon%2BEarth%2B%25281%2529.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="630" data-original-width="1200" height="336" src="https://1.bp.blogspot.com/-M3vhjfvCNqE/Xh0fy4OlXbI/AAAAAAAARzc/usz34MYZpfg3ozdozbowB7DPDL4o0xxYACLcBGAsYHQ/s640/7%2BBillion-Year-Old%2BStardust%2BIs%2BOldest%2BMaterial%2BFound%2Bon%2BEarth%2B%25281%2529.jpg" width="640" /></a></div> <br /> <br /> <br /> <span style="font-family: "georgia" , "times new roman" , serif;">Scientists recently identified the oldest material on Earth: stardust that's 7 billion years old, tucked away in a massive, rocky meteorite that struck our planet half a century ago. </span><br /> <br /> Stars have life cycles. They're born when bits of dust and gas floating through space find each other and collapse in on each other and heat up. They burn for millions to billions of years, and then they die. When they die, they pitch the particles that formed in their winds out into space, and those bits of stardust eventually form new stars, along with new planets and moons and meteorites. And in a meteorite that fell fifty years ago in Australia, scientists have now discovered stardust that formed 5 to 7 billion years ago -- the oldest solid material ever found on Earth.<br /> <br /> "This is one of the most exciting studies I've worked on," says Philipp Heck, a curator at the Field Museum, associate professor at the University of Chicago, and lead author of a paper describing the findings in the Proceedings of the National Academy of Sciences. "These are the oldest solid materials ever found, and they tell us about how stars formed in our galaxy."<br /> <br /> The materials Heck and his colleagues examined are called presolar grains-minerals formed before the Sun was born. "They're solid samples of stars, real stardust," says Heck. These bits of stardust became trapped in meteorites where they remained unchanged for billions of years, making them time capsules of the time before the solar system..<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> But presolar grains are hard to come by. They're rare, found only in about five percent of meteorites that have fallen to Earth, and they're tiny-a hundred of the biggest ones would fit on the period at the end of this sentence.<br /> <br /> But the Field Museum has the largest portion of the Murchison meteorite, a treasure trove of presolar grains that fell in Australia in 1969 and that the people of Murchison, Victoria, made available to science. Presolar grains for this study were isolated from the Murchison meteorite for this study about 30 years ago at the University of Chicago.<br /> <br /> "It starts with crushing fragments of the meteorite down into a powder ," explains Jennika Greer, a graduate student at the Field Museum and the University of Chicago and co-author of the study. "Once all the pieces are segregated, it's a kind of paste, and it has a pungent characteristic-it smells like rotten peanut butter."<br /> <br /> This "rotten-peanut-butter-meteorite paste" was then dissolved with acid, until only the presolar grains remained. "It's like burning down the haystack to find the needle," says Heck.<br /> <br /> Once the presolar grains were isolated, the researchers figured out from what types of stars they came and how old they were. "We used exposure age data, which basically measures their exposure to cosmic rays, which are high-energy particles that fly through our galaxy and penetrate solid matter," explains Heck. "Some of these cosmic rays interact with the matter and form new elements. And the longer they get exposed, the more those elements form.<br /> <br /> "I compare this with putting out a bucket in a rainstorm. Assuming the rainfall is constant, the amount of water that accumulates in the bucket tells you how long it was exposed," he adds. By measuring how many of these new cosmic-ray produced elements are present in a presolar grain, we can tell how long it was exposed to cosmic rays, which tells us how old it is.<br /> <br /> The researchers learned that some of the presolar grains in their sample were the oldest ever discovered-based on how many cosmic rays they'd soaked up, most of the grains had to be 4.6 to 4.9 billion years old, and some grains were even older than 5.5 billion years. For context, our Sun is 4.6 billion years old, and Earth is 4.5 billion.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> But the age of the presolar grains wasn't the end of the discovery. Since presolar grains are formed when a star dies, they can tell us about the history of stars. And 7 billion years ago, there was apparently a bumper crop of new stars forming-a sort of astral baby boom.<br /> <br /> "We have more young grains that we expected," says Heck. "Our hypothesis is that the majority of those grains, which are 4.9 to 4.6 billion years old, formed in an episode of enhanced star formation. There was a time before the start of the Solar System when more stars formed than normal."<br /> <br /> This finding is ammo in a debate between scientists about whether or not new stars form at a steady rate, or if there are highs and lows in the number of new stars over time. "Some people think that the star formation rate of the galaxy is constant," says Heck. "But thanks to these grains, we now have direct evidence for a period of enhanced star formation in our galaxy seven billion years ago with samples from meteorites. This is one of the key findings of our study."<br /> <br /> Heck notes that this isn't the only unexpected thing his team found. As almost a side note to the main research questions, in examining the way that the minerals in the grains interacted with cosmic rays, the researchers also learned that presolar grains often float through space stuck together in large clusters, "like granola," says Heck. "No one thought this was possible at that scale."<br /> <br /> Heck and his colleagues look forward to all of these discoveries furthering our knowledge of our galaxy. "With this study, we have directly determined the lifetimes of stardust. We hope this will be picked up and studied so that people can use this as input for models of the whole galactic life cycle," he says.<br /> <br /> Heck notes that there are lifetimes' worth of questions left to answer about presolar grains and the early Solar System. "I wish we had more people working on it to learn more about our home galaxy, the Milky Way," he says.<br /> <br /> "Once learning about this, how do you want to study anything else?" says Greer. "It's awesome, it's the most interesting thing in the world."<br /> <br /> "I always wanted to do astronomy with geological samples I can hold in my hand," says Heck. "It's so exciting to look at the history of our galaxy. Stardust is the oldest material to reach Earth, and from it, we can learn about our parent stars, the origin of the carbon in our bodies, the origin of the oxygen we breathe. With stardust, we can trace that material back to the time before the Sun."<br /> <br /> "It's the next best thing to being able to take a sample directly from a star," says Greer.<br /> <br /> This study was contributed to by researchers from the Field Museum, University of Chicago, Lawrence Livermore National Laboratory, Washington University, Harvard Medical School, ETH Zurich, and the Australian National University. Funding was provided by NASA, the TAWANI Foundation, the National Science Foundation, the Department of Energy, the Swiss National Science Foundation, the Brazilian National Council for Scientific and Technological Development and the Field Museum's Science and Scholarship Funding Committee.<br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.fieldmuseum.org/about/press/meteorite-contains-oldest-material-earth-7-billion-year-old-stardust" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.fieldmuseum.org/" rel="nofollow" target="_blank">Field Museum</a>.</span></i></u></div>

7 Billion-Year-Old Stardust Is Oldest Material Found on Earth

Scientists recently identified the oldest material on Earth: stardust that's 7 billion years old, tucked away in a massive, rocky ...

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Scientists Catch a Volcano Mid-formation in the Indian Ocean

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-x6WprxkIMlk/XhYGhjerY2I/AAAAAAAARzE/3Of1yfeho3gDNpXyYsaaJUVaBQQx6gexgCLcBGAsYHQ/s1600/Scientists%2BCatch%2Ba%2BVolcano%2BMid-formation%2Bin%2Bthe%2BIndian%2BOcean%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Scientists Catch a Volcano Mid-formation in the Indian Ocean" border="0" data-original-height="1049" data-original-width="1216" height="552" src="https://1.bp.blogspot.com/-x6WprxkIMlk/XhYGhjerY2I/AAAAAAAARzE/3Of1yfeho3gDNpXyYsaaJUVaBQQx6gexgCLcBGAsYHQ/s640/Scientists%2BCatch%2Ba%2BVolcano%2BMid-formation%2Bin%2Bthe%2BIndian%2BOcean%2B%25281%2529.jpg" title="" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">This illustration shows how magma in a reservoir deep underground ascended to form a submarine volcano in the Indian Ocean.  (Image credit: James Tuttle Keane/Nature Geoscience (2020))</td></tr> </tbody></table> <br /> <span style="font-family: "georgia" , "times new roman" , serif;">Mysterious seismic hums detected around the world were likely caused by an unusual geologic event — the rumblings of a magma-filled reservoir deep under the Indian Ocean, a new study finds. </span><br /> <br /> These odd hums were an unconventional geologic birth announcement. A few months after the sounds rippled around the Earth, a new underwater volcano was born off the coast of the island of Mayotte, located between Madagascar and Mozambique in the Indian Ocean.<br /> <br /> Since May 2018, an unusual sequence of earthquakes has been recorded off the coast of the island of Mayotte in the Comoros archipelago between Africa and Madagascar. Seismic activity began with a swarm of thousands of "seemingly tectonic" earthquakes, culminating in an earthquake of magnitude 5.9 in May 2018. Mostly, since June 2018, however, a completely new form of earthquake signal has emerged that was so strong that it could be recorded up to 1000 kilometers away. <br /> <br /> These 20- to 30-minute-long signals are characterized by particularly harmonic, low frequencies, almost monochromatic, similar to a large bell or a double bass, and are called very long period (VLP) signals. Although the centre of the seismic activity was located almost 35 kilometers offshore the east of the island, a continuous lowering and eastward motion of the Earth's surface at Mayotte had begun at the same time as the massive swarms of VLP events started, accumulating to almost 20 cm to date.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Although there was no evidence of earlier volcanic activity in the epicenter of the seismic activity, GFZ scientists had suspected magmatic processes from the beginning—quake swarms in the upper crust that often arise as a reaction to the rise of magma and VLPs in earlier years were associated with the collapse of large caldera volcanoes.<br /> <br /> The special frequency content of the VLP signals is caused by the resonance oscillation of the buried magma chamber. The deeper the vibrations, the larger the magma reservoir. However, the earthquake swarms under the ocean floor were much deeper than with other volcanoes and the resonance tones of the VLPs were unusually low and strong.<br /> <br /> An international team led by GFZ scientist Simone Cesca analyzed seismological and geodetic data from the region to study these observations and their evolution over time. However, the investigations were complicated by the fact that there was no seismic network on the ocean floor, and therefore, measurements were only available at great distances on Mayotte, Madagascar and in Africa. "We tried to improve the unfavorable initial situation by developing special new analytical methods such as cluster and directional beam methods," says Cesca.<br /> <br /> The team identified different activity phases within the sequence of events from May 2018 to today. The initial swarm phase indicated a rapid upward movement of magma from a deep mantle reservoir more than 30 kilometers below the Earth's surface. Once an open channel had formed from the Earth's mantle to the seabed, the magma began to flow unhindered and form a new underwater volcano. A French oceanographic campaign recently confirmed the birth of the submarine volcano, whose location coincides with the reconstructed magma rise.<br /> <br /> In this phase, the apparent tectonic earthquake activity decreased again, while the lowering of the ground on the island of Mayotte began. Likewise, long-lasting monofreququent VLP signals started. "We interpret this as a sign of the collapse of the deep magma chamber off the coast of Mayotte," explains Eleonora Rivalta, co-author of the scientific team. "It is the deepest (~30 km) and largest magma reservoir in the upper mantle (more than 3.4 cubic kilometers) to date, which is beginning to empty abruptly.<br /> <br /> "Since the seabed lies 3 kilometers below the water surface, almost nobody noticed the enormous eruption. However, there are still possible hazards for the island of Mayotte today, as the Earth's crust above the deep reservoir could continue to collapse, triggering stronger earthquakes," says Torsten Dahm, head of the section Physics of Earthquakes and Volcanoes at the GFZ.<br /> <br /> In all, about 0.4 cubic miles (1.5 cubic km) of magma drained out of the reservoir, the researchers calculated. However, given the vast size of the volcano, it's likely that even more magma was involved, Cesca noted.<br /> <br /> Although the volcano is now formed, earthquakes may still rattle the area.<br /> <br /> "There are still possible hazards for the island of Mayotte today," study senior researcher and head of the section Physics of Earthquakes and Volcanoes at the GFZ Torsten Dahm, said in a statement "The Earth's crust above the deep reservoir could continue to collapse, triggering stronger earthquakes."<br /> <span style="font-family: "georgia" , "times new roman" , serif;"> <br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="http://dx.doi.org/10.1038/s41561-019-0505-5" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.helmholtz.de/en/" rel="nofollow" target="_blank">Helmholtz Association of German Research Centres.</a></span></i></u></span></div>

Scientists Catch a Volcano Mid-formation in the Indian Ocean

This illustration shows how magma in a reservoir deep underground ascended to form a submarine volcano in the Indian Ocean.  (Image credi...

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Crater From Asteroid Impact That Covered 10% of Earth's Surface in Debris

<div dir="ltr" style="text-align: left;" trbidi="on"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://1.bp.blogspot.com/-0cE9ORW9uXE/XhSvwQMXB2I/AAAAAAAARyo/HoSQp-ox6sAIx7CDGZmFhYTa_d-GGcFqACLcBGAsYHQ/s1600/Crater%2BFrom%2BAsteroid%2BImpact%2BThat%2BCovered%2B10%2525%2Bof%2BEarth%2527s%2BSurface%2Bin%2BDebris.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Crater From Asteroid Impact That Covered 10% of Earth's Surface in Debris" border="0" data-original-height="574" data-original-width="1153" height="318" src="https://1.bp.blogspot.com/-0cE9ORW9uXE/XhSvwQMXB2I/AAAAAAAARyo/HoSQp-ox6sAIx7CDGZmFhYTa_d-GGcFqACLcBGAsYHQ/s640/Crater%2BFrom%2BAsteroid%2BImpact%2BThat%2BCovered%2B10%2525%2Bof%2BEarth%2527s%2BSurface%2Bin%2BDebris.jpg" title="" width="640" /></a></div> <br /> <br /> A flash of light would have come first, followed by a shockwave and massive earthquake. Only later would the hailstorm of black, glassy debris begun to fall, a rocky rain that would touch 10 percent of the planet's surface.<br /> <br /> A team of researchers with members from Singapore, the U.S., Thailand and Laos has concluded that the impact point of a meteorite that struck the Earth approximately 790,000 years ago lies buried beneath a volcanic field in southern Laos. In their paper published in Proceedings of the National Academy of Sciences, the group outlines four lines of evidence that point to the Bolaven volcanic field as the likely site of the meteorite strike.<br /> <br /> Prior research has shown that approximately 790,000 years ago, a large meteorite (the largest known young meteorite impact) struck Earth in the Eastern Hemisphere. So great was the impact that debris was strewn across a tenth of the entire planet's surface.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Scientists know about the impact because of bits of glassy clasts known as tektites have been found in places like Antarctica, Australia and Southeast Asia. <br /> <br /> Prior evidence also suggested the impact site was likely somewhere in Southeast Asia, but until now, the exact location has been unknown. In this new effort, the researchers have found evidence that suggests the reason the crater has not been found is that it is hidden beneath a volcanic field—and they provide four lines of evidence to back up their claim.<br /> <br /> The first line of evidence involved the geochemistry of the tektites in the vicinity of the Bolaven volcanic field—the researchers claim it implies the presence of basalts at the impact site. The second line involved geologic mapping and dating of basaltic lavas that existed before and after the time of the impact, which showed a change occurred around the time of the impact. The fourth line of evidence came from gravity measurements the team took at the Bolaven volcanic field—they report an anomaly that suggests the presence of a 13- to 17-kilometer crater. <br /> <br /> The final piece of evidence came from what the team describes as an outcrop of crudely layered sandstone and mudstone boulders 10 to 20 kilometers from the Bolaven volcanic field, which appear to have been thrown there by the force of the meteorite striking the ground.<br /> <br /> The researchers suggest that taken together, their four lines of evidence very strongly suggest that the impact site for the ancient meteorite was the Bolaven volcanic field.<br /> <br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.pnas.org/content/early/2019/12/24/1904368116" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.pnas.org/" rel="nofollow" target="_blank">Proceedings of the National Academy of Sciences.</a></span></i></u></div>

Crater From Asteroid Impact That Covered 10% of Earth's Surface in Debris

A flash of light would have come first, followed by a shockwave and massive earthquake. Only later would the hailstorm of black, glassy...

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What is Fire Opal?

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-NpJg2xeNv3k/XhNr0mIYJuI/AAAAAAAARyc/P5noG4MXNOkO_r0k2ZyG1trTScJSDYF_ACLcBGAsYHQ/s1600/Fire%2BOpal.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Fire Opal" border="0" data-original-height="1014" data-original-width="1352" height="480" src="https://1.bp.blogspot.com/-NpJg2xeNv3k/XhNr0mIYJuI/AAAAAAAARyc/P5noG4MXNOkO_r0k2ZyG1trTScJSDYF_ACLcBGAsYHQ/s640/Fire%2BOpal.jpg" title="" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">Stunning Mexican Fire Opal. Photo: Jeff Schultz</td></tr> </tbody></table> <br /> <br /> <b>Fire opal</b> is a transparent to translucent opal, with warm body colors of yellow to orange to red. Although it does not usually show any play of color, occasionally a stone will exhibit bright green flashes. <br /> <br /> Like other opals, fire opal is <b>amorphous </b>hydrated silicon dioxide by chemical composition. "Amorphous" indicates that opal has no crystalline structure; "hydrated" means that it contains water, typically from 3 to 10%. Opal is actually considered to be a kind of hardened jelly. But fire opal has some unusual characteristics not shared by other opals.<br /> <br /> Fire opal glows with the <b>fire of the sun</b>: hot honey yellows, oranges, and reds so bright they look as though they might glow in the dark. Fire opal sometimes only occasionally exhibits an opalescence or play of color like other opals but it does not need this to take a starring role in jewelry. Its juicy color is just the right accent to earth tones or black and also looks great paired with other bright tones.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Fire opals that do not show play of color are sometimes referred to as jelly opals. <br /> <br /> Fire opal is associated particularly with Mexico, and is mined in the Mexican states of Queretaro, Hidalgo, Guerrero, Michoacan, Julisio, Chihuahua and San Luis Potosi. The most important mines in Queretaro were discovered in 1835 and are still producing today. Small quantities of fire opal can also be found in Oregon in the USA and British Columbia in Canada.<br /> <br /> Mexican opals are sometimes cut in their ryholitic host material if it is hard enough to allow cutting and polishing. This type of Mexican opal is referred to as a Cantera opal. Also, a type of opal from Mexico, referred to as Mexican water opal, is a colorless opal which exhibits either a bluish or golden internal sheen.<br /> <br /> Unlike most opal, fire opal is sometimes <b>faceted</b>, so you can choose sparkle as well as color. Because it is light as well as bright, fire opal is especially good for earrings, where even small sizes have a big punch of color.  Only the very finest qualities of Fire Opal are suitable for faceting. <br /> <br /> Since fire opal has a high <b>water content</b>, it should be protected from heat and prolonged exposure to strong light, which could dry it out. Lapidaries cure fire opal by drying it before cutting to reduce instability, so it is actually not that delicate. But due to its relative softness, it is best suited for pendants, earrings, not everyday rings.<br /> <h4 style="text-align: left;"> <span style="color: blue;"><span style="font-family: "georgia" , "times new roman" , serif;">Video:  </span></span></h4> <div class="facebook-responsive"> <iframe allowfullscreen="true" allowtransparency="true" frameborder="0" height="315" scrolling="no" src="https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2FAmazingGeologist%2Fvideos%2F437730813474227%2F&show_text=0&width=560" style="border: none; overflow: hidden;" width="560"></iframe><br /></div> <b><span style="font-family: "georgia" , "times new roman" , serif;">See also: </span></b><br /> <span style="font-family: "georgia" , "times new roman" , serif;"><a href="https://www.geologyin.com/2017/12/how-does-opal-get-its-color.html" target="_blank">How Does Opal Get Its Color?</a></span><br /> <span style="font-family: "georgia" , "times new roman" , serif;"><a href="https://www.geologyin.com/2016/06/types-of-opal-with-photos.html" target="_blank">Types of Opal With Photos </a></span><br /> <span style="font-family: "georgia" , "times new roman" , serif;"><span style="font-family: "georgia" , "times new roman" , serif;"><a href="https://www.geologyin.com/2019/07/what-is-crazy-lace-agate.html" target="_blank">What is Crazy Lace Agate? </a></span></span></div>

What is Fire Opal?

Stunning Mexican Fire Opal. Photo: Jeff Schultz Fire opal is a transparent to translucent opal, with warm body colors of yellow to o...

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What is the Lifespan of Volcanic Islands Like Hawaii?

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-IZXocqB5qAQ/XhDEalMkGNI/AAAAAAAARyQ/socyOlzA4m8Eeh4aYVmpzqRRc659P-jYgCLcBGAsYHQ/s1600/What%2Bis%2Bthe%2BLifespan%2Bof%2BVolcanic%2BIslands%2BLike%2BHawai.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="765" data-original-width="1147" height="265" src="https://1.bp.blogspot.com/-IZXocqB5qAQ/XhDEalMkGNI/AAAAAAAARyQ/socyOlzA4m8Eeh4aYVmpzqRRc659P-jYgCLcBGAsYHQ/s400/What%2Bis%2Bthe%2BLifespan%2Bof%2BVolcanic%2BIslands%2BLike%2BHawai.jpg" width="400" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">Nishinoshima island</td></tr> </tbody></table> <br /> <div style="text-align: left;"> When a hot plume of rock rises through the Earth's mantle to puncture the overlying crust, it can create not only a volcanic ocean island, but also a swell in the ocean floor hundreds to thousands of kilometers long. Over time the island is carried away by the underlying tectonic plate, and the plume pops out another island in its place. Over millions of years, this geological hotspot can produce a chain of trailing islands, on which life may flourish temporarily before the islands sink, one by one, back into the sea.<br /> <br /> The Earth is pocked with dozens of hotspots, including those that produced the island chains of Hawaii and the Galapagos. While the process by which volcanic islands form is similar from chain to chain, the time that any island spends above sea level can vary widely, from a few million years in the case of the Galapagos to over 20 million for the Canary Islands. An island's age can determine the life and landscapes that evolve there. And yet the mechanisms that set an island's lifespan are largely unknown.<br /> <br /> Now scientists at MIT have an idea about the processes that determine a volcanic island's age. In a paper published today in Science Advances, they report an analysis of 14 major volcanic island chains around the world. They found that an island's age is related to two main geological factors: the speed of the underlying plate and the size of the swell generated by the hotspot plume.<br /> <br /> For instance, if an island lies on a fast-moving plate, it is likely to have a short lifespan, unless, as is the case with Hawaii, it was also created by a very large plume. The plume that gave rise to the Hawaiian islands is among the largest on Earth, and while the Pacific plate on which Hawaii sits is relatively speedy compared with other oceanic plates, it takes considerable time for the plate to slide over the plume's expansive swell.<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> The researchers found that this interplay between tectonic speed and plume size explains why the Hawaiian islands persist above sea level for million years longer than the oldest Galapagos Islands, which also sit on plates that travel at a similar speed but over a much smaller plume. By comparison, the Canary Islands, among the oldest island chains in the world, sit on the slow-moving Atlantic plate and over a relatively large plume.<br /> <br /> "These island chains are dynamic, insular laboratories that biologists have long focused on," says former MIT graduate student Kimberly Huppert, the study's lead author. "But besides studies on individual chains, there's not a lot of work that related them to processes of the solid Earth, kilometers below the surface."<br /> <br /> "You can imagine all these organisms living on a sort of treadmill made of islands, like stepping stones, and they're evolving, diverging, migrating to new islands, and the old islands are drowning," adds Taylor Perron, associate head of MIT's Department of Earth, Atmospheric and Planetary Sciences. "What Kim has shown is, there's a geophysical mechanism that controls how fast this treadmill is moving and how long the island chains go before they drop off the end."<br /> <br /> Huppert and Perron co-authored the study with Leigh Royden, professor of earth, atmospheric and planetary sciences at MIT.</div> <h4> <span style="font-family: "georgia" , "times new roman" , serif;">Sinking a blowtorch</span></h4> <div style="text-align: left;"> The new study is a part of Huppert's MIT thesis work, in which she looked mainly at the evolution of landscapes on volcanic island chains, the Hawaiian islands in particular. In studying the processes that contribute to island erosion, she dug up a controversy in the literature regarding the processes that cause the seafloor to swell around hotspot islands.<br /> <br /> "The idea was, if you heat some of the bottom of the plate, you can make it go up really fast by just thermal uplift, basically like a blowtorch under the plate," Royden says.<br /> <br /> If this idea is correct, then by the same token, cooling of the heated plate should cause the seafloor to subside and islands to eventually sink back into the ocean. But in studying the ages of drowned islands in hotspot chains around the world, Huppert found that islands drown at a faster rate than any natural cooling mechanism could explain.<br /> <br /> "So most of this uplift and sinking couldn't have been from heating and cooling," Royden says. "It had to be something else."<br /> <div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br /> <ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br /> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script><br /></div> Huppert's observation inspired the group to compare major volcanic island chains in hopes of identifying the mechanisms of island uplift and sinking—which are likely the same processes that set an island's lifespan, or time above sea level.</div> <h4 style="text-align: left;"> <span style="font-family: "georgia" , "times new roman" , serif;">Evolution, on a treadmill</span></h4> <div style="text-align: left;"> In their analysis, the researchers looked at 14 volcanic island chains around the world, including the Hawaiian, Galapagos, and Canary islands. For each island chain, they noted the direction in which the underlying tectonic plate was moving and measured the plate's average speed relative to the hotspot. They then measured, in the direction of each island chain, the distance between the beginning and the end of the swell, or uplift in the crust, created by the underlying plume.<br /> <br /> For every island chain, they divided the swell distance by plate velocity to arrive at a number representing the average time a volcanic island should spend atop the plume's swell—which should determine how long an island remains above sea level before sinking into the ocean.<br /> <br /> When the researchers compared their calculations with the actual ages of each island in each of the 14 chains, including islands that had long since sunk below sea level, they found a strong correlation between the time spent atop the swell and the typical amount of time that islands remain above sea level. A volcanic island's lifespan, they concluded, depends on a combination of the underlying plate's speed and the size of the plume, or swell that it creates.<br /> <br /> Huppert says that the processes that set an island's age can help scientists better understand biodiversity and how life looks different from one island chain to another.<br /> <br /> "If an island spends a long time above sea level, that provides a long time for speciation to play out," Huppert says. "But if you have an island chain where you have islands that drown at a faster rate, then it will affect the ability of fauna to radiate to neighboring islands, and how these islands are populated."<br /> <br /> The researchers posit that, in some sense, we have the interplay of tectonic speed and plume size to thank for our modern understanding of evolution.<br /> <br /> "You're looking at a process in the solid Earth which is contributing to the fact that the Galapagos is a very fast moving treadmill, with islands moving off very quickly, with not a long time to erode, and this was the system that led to people discovering evolution," Royden notes. "So in a sense this process really set the stage for humans to figure out what evolution was about, by doing it in this microcosm. If there hadn't been this process, and the Galapagos hadn't been on that short residence time, who knows how long it would have taken for people to figure it out."<br /> <br /> <br /> <u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://advances.sciencemag.org/content/6/1/eaaw6906" rel="nofollow" target="_blank">materials </a>provided by <a href="http://www.mit.edu/" rel="nofollow" target="_blank">MIT</a>.</span></i></u></div> </div>

What is the Lifespan of Volcanic Islands Like Hawaii?

Nishinoshima island When a hot plume of rock rises through the Earth's mantle to puncture the overlying crust, it can create not ...

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