The Most Complete Baby Mammoth In North America Has Been FOUND

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtX-VKv7Zk95cu38xiXdeFRykLyZLYniyKnNyMw9UxKaEN3bw1GXoRzkf1lOWiYHoXzXx7Kx_6Ml0Jeqgos82W-O1nMKPhpt96OcppqoJoQ_M4c9MVaOjXlHTWoGNGAZg79CyNok_fY5QGLaI53V0x1vMivIK-4zJMs4gnlkvSs4KRfHjiLQXp9QA0/s1252/A%20well-preserved%20whole%20baby%20woolly%20mammoth%20was%20discovered%20at%20Treadstone%20Mine%20in%20the%20Yukon%E2%80%99s%20Eureka%20(3).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="730" data-original-width="1252" height="374" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtX-VKv7Zk95cu38xiXdeFRykLyZLYniyKnNyMw9UxKaEN3bw1GXoRzkf1lOWiYHoXzXx7Kx_6Ml0Jeqgos82W-O1nMKPhpt96OcppqoJoQ_M4c9MVaOjXlHTWoGNGAZg79CyNok_fY5QGLaI53V0x1vMivIK-4zJMs4gnlkvSs4KRfHjiLQXp9QA0/w640-h374/A%20well-preserved%20whole%20baby%20woolly%20mammoth%20was%20discovered%20at%20Treadstone%20Mine%20in%20the%20Yukon%E2%80%99s%20Eureka%20(3).jpg" title="A well-preserved whole baby woolly mammoth was discovered at Treadstone Mine in the Yukon’s Eureka Creek, south of Dawson City, on Tuesday. (Government of Yukon)" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A well-preserved whole baby woolly mammoth was discovered at Treadstone Mine in the Yukon’s Eureka Creek, south of Dawson City, on Tuesday. (Government of Yukon)<br /></td></tr></tbody></table> <br /><p></p><p><span style="font-family: georgia;">Whole baby mammoth, named Nun cho ga, is only 2nd found in the world, 1st in North America</span></p><p>The calf, named 'Nun cho ga', meaning 'big baby animal' in the Hän language, was frozen in permafrost, resulting in its remains being mummified.<br /><br />Miners working in a gold field in Yukon have uncovered what is being called the "most complete" mummified woolly mammoth found to date in North America, officials announced on Friday.<br /><br />A joint statement from the Government of Yukon and Tr'ondek Hwech'in First Nation said that miners working on Eureka Creek in the Klondike gold fields found a frozen, near complete woolly mammoth while excavating through permafrost in Tr'ondek Hwech'in traditional territory.<br /><br />Tr'ondek Hwech'in elders have since named the mammoth calf Nun cho ga, which means "big baby animal" in the Han language.<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />"The Yukon has always been an internationally renowned leader for ice age and Beringia research. We are thrilled about this significant discovery of a mummified woolly mammoth calf: Nun cho ga," Minister of Tourism and Culture Ranj Pillai said.<br /><br />"Without strong partnerships between placer miners, Tr'ondek Hwech'in, and the Yukon government, discoveries like this could not happen."<br /><br />Tr'ondek Hwech'in Chief Roberta Joseph called it a "remarkable recovery" for the First Nation and said she looked forward to collaborating with the government on next steps "in a way that honours our traditions, culture, and laws."<br /><br />"We are thankful for the Elders who have been guiding us so far and the name they provided. We are committed to respectfully handling Nun cho ga as she has chosen now to reveal herself to all of us," Joseph said.<br /><br />Officials called it "the most complete mummified mammoth found in North America."<br /><br />The woolly mammoth appears to be a female and is about the same size as a 42,000-year-old infant woolly mammoth called "Lyuba," who was discovered in Siberia in 2007. A partial mammoth calf, named "Effie," was found at a gold mine in interior Alaska in 1948.<br /><br />Officials say geologists from the Yukon Geological Survey and University of Calgary, who recovered "Nun cho ga," believe she died and froze in permafrost during the ice age more than 30,000 years ago.<br /><br />"As an ice age paleontologist, it has been one of my life long dreams to come face-to-face with a real woolly mammoth. That dream came true today," Grant Zazula said.<br /><br />"Nun cho ga is beautiful and one of the most incredible mummified ice age animals ever discovered in the world. I am excited to get to know her more."<p></p><p><span style="background-color: #eeeeee;"><span style="font-family: arial;">The woolly mammoth roamed the icy tundra of Europe and North America for 140,000 years, disappearing at the end of the Pleistocene period, 10,000 years ago.<br /><br />They are one of the best understood prehistoric animals known to science because their remains are often not fossilised but frozen and preserved.<br /><br />Males were around 12 feet (3.5m) tall, while the females were slightly smaller.<br /><br />Curved tusks were up to 16 feet (5m) long and their underbellies boasted a coat of shaggy hair up to 3 feet (1m) long.</span></span></p><p><u> </u></p><p><u>The above story is based on <a href="https://yukon.ca/en/news/mummified-baby-woolly-mammoth-found-gold-miner-klondike" rel="nofollow" target="_blank">materials </a>provided by<i> Government of Yukon.</i> </u><br /></p>

The Most Complete Baby Mammoth In North America Has Been FOUND

A well-preserved whole baby woolly mammoth was discovered at Treadstone Mine in the Yukon’s Eureka Creek, south of Dawson City, on Tuesday. ...

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Utah Geologists Translate Vibrations of Rocky Landforms Into Audible Tones

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK88p-kojmXZLO9hGKAJ6Edrs2E9ehZZgSNLYuawdJ-vpftvdJeJGUcWTIDiY9hz_oZQ3nwSLi5mUq8Vh8sWLxIs6nZ9G9mk-aDZgi4aN7KeXMvr7Ou61iv7bKOKUY_ZfFawxLUr0Kt0Ve46JSrpm5pgP3eSOJAlWKWmZlBHZ8p1NwdoRPDoYZtFpA/s1213/Utah%20geologists%20translate%20vibrations%20of%20rocky%20landforms%20into%20audible%20tones.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="683" data-original-width="1213" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK88p-kojmXZLO9hGKAJ6Edrs2E9ehZZgSNLYuawdJ-vpftvdJeJGUcWTIDiY9hz_oZQ3nwSLi5mUq8Vh8sWLxIs6nZ9G9mk-aDZgi4aN7KeXMvr7Ou61iv7bKOKUY_ZfFawxLUr0Kt0Ve46JSrpm5pgP3eSOJAlWKWmZlBHZ8p1NwdoRPDoYZtFpA/w640-h360/Utah%20geologists%20translate%20vibrations%20of%20rocky%20landforms%20into%20audible%20tones.jpg" title="Utah Geologists Translate Vibrations of Rocky Landforms Into Audible Tones" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">PHOTO CREDIT: Geohazards research group</td></tr></tbody></table> <p style="text-align: left;"><span style="font-family: georgia;">These are the vibrations of Eagle Plume Tower, a rock landform in Southeastern Utah.</span></p><p style="text-align: left;"><span style="font-family: georgia;">You won't see them move no matter how closely you watch.<br /><br />You won't hear their vibrations, even with your ear pressed to the cool sandstone. </span><br /><br />But new research shows that the red rock towers found in Southern Utah and throughout the Colorado Plateau are in constant motion, vibrating with their own signature rhythms as unique as their dramatic profiles against the depth of the blue desert sky.<br /><br />University of Utah researchers know well how rock towers and arches shimmy, twist and sway in response to far-off earthquakes, wind and even ocean waves. Their latest research compiles a first-of-its-kind dataset to show that the dynamic properties, i.e. the frequencies at which the rocks vibrate and the ways they deform during that vibration, can be largely predicted using the same mathematics that describe how beams in built structures resonate.<br /><br />Knowing these properties is crucial to understanding the seismic stability of a rock tower and its susceptibility to hazardous vibrations. But it’s tough to get the needed data, partly because getting to the base of the towers often requires traveling through treacherous terrain—and then someone has to climb them to place a seismometer at the top.<br /><br />With the help of experienced climbers, though, University of Utah researchers have now measured the dynamic properties of 14 rock towers and fins in Utah, creating a unique dataset with a variety of heights and tower shapes.<br /><br />“This ability to make predictions about a tower’s fundamental frequency using just the tower’s width, height, and material properties is powerful because that means someone doesn’t necessarily have to climb a 300-foot (100 m) tower with a seismometer to get this information,” says lead author Riley Finnegan, a doctoral student in geophysics. “And knowing this information is important for any assessments related to the seismic stability of a tower or potential vibration damage.”<br /></p><h4 style="text-align: left;"><span style="font-family: georgia;">Scaling the tops of towers</span></h4><p style="text-align: left;">Finnegan, Jeff Moore, associate professor of geology and geophysics, and colleagues have spent years measuring and cataloging arches and other rock forms to understand how they move. You can see their 3D models here and read about their studies of Rainbow Bridge, Castleton Tower, multiple arches including Delicate Arch and even the Matterhorn.<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />Their new dataset includes the 279-foot (85 m) high monolith of Eagle Plume Tower and the 147-foot (45 m) high Petard Tower, both in Valley of the Gods, Bears Ears, Utah.<br /><br />Find photos, videos, animations of exaggerated tower movement, and even sped-up sound recordings of tower <a href="https://geohazards.earth.utah.edu/media.html" rel="nofollow" target="_blank">vibrations here.</a><br /><br />To get their seismometers to the tops of these towers, the researchers teamed up with climbing expert Kathryn Vollinger, who together with her partner ascended the towers hauling the instruments to the top. Then they waited while the instruments recorded data and carried them back down.<br /><br />The researchers drew on the help of others as well. Jackson Bodtker, a recent graduate now at the University of Calgary, climbed three towers in one day. Alex Dzubay, a senior majoring in geophysics, scrambled up a thousand-foot cliff to access one tower. Moore’s family even contributed, measuring dimensions of rock towers in Arizona.<br /><br />“So many talented, eager, and helpful people were involved in the fieldwork,” Finnegan says. “A group of us went to three of the sites after Kathryn’s climbs to fly the drone to make 3D models, and I personally could barely get to the baseof one of the towers, let alone start thinking about carrying our equipment to the base and then climb up with it all in tow.”<br /><p></p><h4 style="text-align: left;"><span style="font-family: georgia;">Respecting the land</span></h4><p style="text-align: left;">Some of the sites studied have special significance to local Native American tribes, including the towers in Valley of the Gods, Bears Ears, Utah. The valley, according to the Bears Ears Inter-Tribal Coalition, “…is considered sacred to the Navajo, who interpret the giant sandstone monuments as ancient Navajo warriors frozen in stone—and time.”<br /><br />Finnegan says the researchers met with teachers from Whitehorse High in Montezuma Creek near Valley of the Gods and that one of the students, Weston Manygoats, joined them for fieldwork. “He is extremely bright and hardworking, and we were very grateful for his assistance,” Finnegan says.<br /><br />The research team strove to practice respectful visitation during their fieldwork, and recommends that others visiting the Bears Ears area consult with guidelines from the Coalition and visit the Friends of Cedar Mesa Visitor Center in Bluff, UT. Visitors are asked to stay on marked trails, visit cultural sites with respect, leave any cultural objects as they are found, and avoid touching rock art.<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />“We hope that by recognizing these towers are constantly in motion, trembling, swaying and shuddering in response to wind and energy coursing through the Earth, visitors to these sometimes sacred landscapes will have an added layer of respect, and ultimately that our measurements will inspire a spirit of care for these amazingly unique places,” Moore says.<br /><p></p><h4 style="text-align: left;"><span style="font-family: georgia;">Rocks swaying like trees</span></h4><p style="text-align: left;">In all, this study compiled ambient vibration data for 14 rock towers and fins collected over several years.  While the team had previously reported measurements from a single landform, the 120 m high Castleton Tower, the new compilation is larger and broader than any previously published dataset and spans a variety of tower heights and geometries.<br /><br />The results showed that the fundamental frequencies of the rock towers varied between ~1 Hz (one cycle per second) and 15 Hz, and that larger towers have lower fundamental frequencies. In general, the towers bend and sway like trees and tall buildings. At higher frequencies the towers twist around their central axis.<br /><br />“Probably most surprising to me was how well our data agreed with theory, and how well our models supported the data,” Finnegan says. That theory predicts that the fundamental frequency at which a beam vibrates is proportional to its width divided by its height squared. The rock towers largely followed that relationship.<br /><br />The predicted frequencies of the rock towers’ vibrations differed from the observed data by about 4%. And the predicted angle of the towers’ motions deviated from the actual data by 14° on average.”<br /><br />“Maybe I’m overly excited and surprised about this,” Finnegan says, “but I’ve made enough models of rock arches in some of our other work that frustratingly didn’t produce strong matches to the data, so it was refreshing to me to be able to predict tower modes given the geometry.”<br /><br />The new measurements, together with previously published data, provide guidance on estimating the natural frequencies of other rock towers, pillars and fins, in different settings across the world, values which are needed in order to conduct seismic stability and vibration risk assessments, as well as assess the probable intensity of past shaking. Knowing how to predict rock towers’ properties, Finnegan says, makes it much easier to assess the health of a tower with fewer measurements.<br /><br />“Some of the most rewarding times I have had in the field are times when I’m able to slow down, sit and listen and imagine these towers in motion,” Moore says. “We can’t see or hear or feel their motion, but it is very real and is always (and has always been) happening. For me, this new perspective creates a renewed and intimate connection with the landscape.”</p><h4 style="text-align: left;"><span style="font-family: georgia;">You can listen to of their <a href="https://geohazards.earth.utah.edu/media.html" rel="nofollow" target="_blank">rock music at</a>  <span style="color: #2b00fe;"><b><a href="https://geohazards.earth.utah.edu/images/towers/Eagle_50X.mp3" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; font-size: 12.8px; font-style: normal; font-variant-caps: normal; font-variant-ligatures: normal; letter-spacing: normal; outline: currentcolor none medium; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Eagle Plume Tower</a> ,  <a href="https://geohazards.earth.utah.edu/images/towers/TidesofMind_50X.mp3" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; font-size: 12.8px; font-style: normal; font-variant-caps: normal; font-variant-ligatures: normal; letter-spacing: normal; outline: currentcolor none medium; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Tides of Mind</a></b></span></span></h4><p><i><u> The above story is based on <a href="https://attheu.utah.edu/facultystaff/measuring-the-tempo-of-utahs-red-rock-towers/" rel="nofollow" target="_blank">materials </a>provided by th<a href="https://utah.edu/" rel="nofollow" target="_blank">e University of Utah.</a></u></i><br /></p>

Utah Geologists Translate Vibrations of Rocky Landforms Into Audible Tones

PHOTO CREDIT: Geohazards research group   These are the vibrations of Eagle Plume Tower, a rock landform in Southeastern Utah. You won't...

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Tectonics of Convergent Plate Margins: New Insights Into Continental Geology

<p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjA4VGOS4XgHoj41y5N__XXAiXQ-9ZDxbsRNP3Vy63tH2ppqw0qKjXDwKJPayQVGqTRHHVjqoOA3xgmbTTr5bhswTS7DGu2-dj9HY2WW_ObUaoJ-UbiWyBKhkV9Xu2Eo97DKuYUmMRpVqn5zLFAOxrOTRKFnf6qqzIIkTmCDZz7RJHWjQMyMINtQrb9/s980/Low-Res_15.png%20(1).png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="726" data-original-width="980" height="474" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjA4VGOS4XgHoj41y5N__XXAiXQ-9ZDxbsRNP3Vy63tH2ppqw0qKjXDwKJPayQVGqTRHHVjqoOA3xgmbTTr5bhswTS7DGu2-dj9HY2WW_ObUaoJ-UbiWyBKhkV9Xu2Eo97DKuYUmMRpVqn5zLFAOxrOTRKFnf6qqzIIkTmCDZz7RJHWjQMyMINtQrb9/w640-h474/Low-Res_15.png%20(1).png" title="Tectonics of Convergent Plate Margins: New Insights Into Continental Geology" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><i><span style="font-family: times;">(a) Low-angle subduction, compressional regime prevails in the overlying plate. Because the plate interface is at low geothermal gradients, the subducting crust experiences ultrahigh pressure eclogite facies metamorphic dehydration at subarc depths, where partial melting of the hydrated small mantle wedge does not immediately happen and thus lack of arc magmatism. (b) High-angle subduction, rollback of the subducting slab results in its decoupling with the mantle wedge at subarc depths, leading to elevation of the geothermal gradient in the subduction zone and switch to extensional regime forming lithospheric rifting in the overlying plate. This would cause not only dehydration melting of the subducting crust but also partial melting of the metasomatites in the small mantle wedge. Credit: Science China Press</span></i></td></tr></tbody></table> <br /></p><p>This study is led by Prof. Yong-Fei Zheng at University of Science and Technology of China. It focuses on the development of tectonic processes along convergent plate margins through inspection of recent advances in the fields of geology, geochemistry, geophysics and geodynamics. </p><p>These advances are fundamental to our understanding of various phenomena at active and fossil plate margins, providing new insights into many first-order problems regarding geological occurrences in the interior of continents. They have great bearing on the transformation from accretionary and collisional orogens along actively convergent margins to rift failure orogens due to reactivation of fossil suture zones. <br /><br />Convergent plate margins occur when two adjoining tectonic plates come together to form either a subduction zone, where at least one of the converging plates is oceanic and plunges beneath the other into the mantle, or a collision zone, where two continents or a continent and a magmatic arc collide. Convergent plate margins are arguably the most dynamic plate boundaries on Earth and have been the subject of many investigations and discussions since the advent of plate tectonic theory in the middle 1960s. </p><p>They show the varied, heterogeneous and complex structure in both space and time due to the multiple geological, physical and chemical processes operating at these zones. Although the largest portion of convergent systems is hidden deep beneath the surface, Zheng and his colleagues have recognized a series of fundamental similarities and differences between active and fossil convergent plate margins. <br /><br />According to the geometric structure, dynamic regime and thermal state of convergent plate margins, Zheng and his colleagues categorize them into three stages during their formation and evolution. The early stage is characterized by low-angle subduction in a compressional regime at low geothermal gradients, giving rise to Alpine to Barrovian type metamorphism but no mafic arc magmatism. The late stage is associated with high-angle subduction in an extensional regime at high geothermal gradients, giving rise to Barrovian to Buchen type metamorphism and mafic arc magmatism. The post stage is characterized by extensional regimes at high geothermal gradients with neither subduction not collision, giving rise to Buchan type metamorphism and granitic magmatism. <br /><br />The formation of Alpine type blueschist facies to eclogite facies metamorphic rocks marks the subduction at low geothermal gradients, and the formation of Barrovian type amphibolite to granulite facies metamorphic rocks in the kyanite stability field indicates the collisional thickening at medium geothermal gradients through compressional shortening. Zheng and his colleagues have found two steps during the transformation from subduction zones to rifting zones. </p><p>The first step is the foundering and thinning of the thickened lithosphere at convergent plate margins, and the second step is the asthenospheric upwelling to fill the space of lithospheric thinning and to transfer heat from the deep mantle to the shallow crust. This results in a significant increase in geothermal gradient and causes the thickened crustal rocks to undergo Buchan type anatectic metamorphism under upper amphibolite to granulite facies conditions in the adalusite to sillimanite stability fields. <br /><br />As generalized by Zheng and his colleagues, material movement at convergent plate margins proceeds in the bottom-up and top-down ways, respectively, corresponding to changes of their thermal state from hot to cold and from cold to hot. In subduction zones, the cold lithosphere sinks into the hot asthenosphere, leading to cooling of the Earth's interior. </p><p>In rifting zone, both heat and material are transferred rifting from the asthenosphere into the crust, resulting in heat loss from the Earth's interior to exterior. Because subduction and rifting are two key mechanisms for the mass and energy exchange between the Earth’s spheres, identifying and distinguishing both tectonic mechanisms and their roles in the formation and evolution of convergent plate margins are the forefront area and major focus of future researches in Earth system science.</p><p><br /><br /><u><i>The above story is based on <a href="https://link.springer.com/article/10.1007/s11430-022-9947-6" rel="nofollow" target="_blank">materials </a>provided by <a href="https://publons.com/publisher/769/science-in-china-press" rel="nofollow" target="_blank">Science China Press. </a></i></u><br /></p>

Tectonics of Convergent Plate Margins: New Insights Into Continental Geology

(a) Low-angle subduction, compressional regime prevails in the overlying plate. Because the plate interface is at low geothermal gradients, ...

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Weird Water Dynamics Fuel Deep Earthquakes and Fist-Sized Diamonds

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkhMzKodeB5UvtFYARNv-lQ2MyuUj-aBfO5OuqkStZklEhjYnY1xHJRzvmUuAgIXry8v_kCK0OhTDF5XEu5ep5rVk94Mlipdv3zZCd0lSQPNSsJN93fpbooNnfcSEhYlMbUS8_g34cSzpd3u0MHLg3GIPsdwo2oNF4muRfIC89BubgTyv2E6t9_srt/s1138/Weird%20Water%20Dynamics%20Fuel%20Deep%20Earthquakes%20and%20Fist-Sized%20Diamonds%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="640" data-original-width="1138" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkhMzKodeB5UvtFYARNv-lQ2MyuUj-aBfO5OuqkStZklEhjYnY1xHJRzvmUuAgIXry8v_kCK0OhTDF5XEu5ep5rVk94Mlipdv3zZCd0lSQPNSsJN93fpbooNnfcSEhYlMbUS8_g34cSzpd3u0MHLg3GIPsdwo2oNF4muRfIC89BubgTyv2E6t9_srt/w640-h360/Weird%20Water%20Dynamics%20Fuel%20Deep%20Earthquakes%20and%20Fist-Sized%20Diamonds%20(1).jpg" title="Weird Water Dynamics Fuel Deep Earthquakes and Fist-Sized Diamonds" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Photo Credit: Debswana Diamond Company</td></tr></tbody></table> <br /><p></p><h4 style="text-align: left;">What causes the deep Earth's most mysterious earthquakes?<br /></h4><p>The cause of Earth's deepest earthquakes has been a mystery to science for more than a century, but a team of Carnegie scientists may have cracked the case.<br /><br />New research published in AGU Advances provides evidence that fluids play a key role in deep-focus earthquakes--which occur between 300 and 700 kilometers below the planet's surface. The research team includes Carnegie scientists Steven Shirey, Lara Wagner, Peter van Keken, and Michael Walter, as well as the University of Alberta's Graham Pearson.<br /><br />Most earthquakes occur close to the Earth's surface, down to about 70 kilometers. They happen when stress builds up at a fracture between two blocks of rock--known as a fault--causing them to suddenly slide past each other.<br /><br />However, deeper into the Earth, the intense pressures create too much friction to allow this kind of sliding to occur and the high temperatures enhance the ability of rocks to deform to accommodate changing stresses. Though theoretically unexpected, scientists have been able to identify earthquakes that originate more than 300 kilometers below the surface since the 1920s.<br /><br />"The big problem that seismologists have faced is how it's possible that we have these deep-focus earthquakes at all," said Wagner. "Once you get a few tens of kilometers down, it becomes incredibly difficult to explain how we are getting slip on a fault when the friction is so incredibly high."<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />Ongoing work over the past several decades has shown us that water plays a role in intermediate-depth earthquakes--those that occur between 70 and 300 kilometers below Earth's surface. In these instances, water is released from minerals, which weakens the rock around the fault and allows the blocks of rock to slip. However, scientists didn't think this phenomenon could explain deep-focus earthquakes, largely because it was believed that water and other fluid-creating compounds couldn't make it far enough down into the Earth's interior to provide a similar effect.<br /><br />This thinking changed for the first time when Shirey and Wagner compared the depths of rare deep-Earth diamonds to the mysterious deep-focus earthquakes.<br /><br />"Diamonds form in fluids" explained Shirey, "if diamonds are there, fluids are there."<br /><br />The diamonds themselves indicated the presence of fluids, however, they also brought samples of the deep-Earth to the surface for the scientists to study. When diamonds form in the Earth's interior, they sometimes capture pieces of mineral from the surrounding rock. These minerals are called inclusions and they may make your jewelry less expensive, but they are invaluable to Earth scientists. They are one of the only ways scientists can study direct samples of our planet's deep interior.<br /><br />The diamond's inclusions had the distinct chemical signature of similar materials found in oceanic crust. This means that the water and other materials weren't somehow created deep in the Earth's interior. Instead, they were carried down as part of a sinking oceanic plate.<br /><br />Said Wagner: "The seismology community had moved away from the idea that there could be water that deep. But diamond petrologists like Steve were showing us samples and saying 'No, no, no. There's definitely water down here' So then we all had to get together to figure out how it got down there."<br /><br />To test the idea, Wagner and van Keken built advanced computational models to simulate the temperatures of sinking slabs at much greater depths than had been attempted before. In addition to the modeling, Walter examined the stabilities of the water-bearing minerals to show that under the intense heat and pressures of the Earth's deep interior, they would, indeed, be capable of holding on to water in certain conditions. The team showed that even though warmer plates didn't hold water, the minerals in the cooler oceanic plates could theoretically carry water to the depths we associate with deep-focus earthquakes.<br /><br />To solidify the study the team compared the simulations to real-life seismological data. They were able to show that the slabs that could theoretically carry water to these depths were also the ones experiencing the previously unexplained deep earthquakes.<br /><br />This study is unusual in applying four different disciplines--geochemistry, seismology, geodynamics, and petrology--to the same question, all of which point to the same conclusion: water and other fluids are a key component of deep-focus earthquakes.<br /><br />"The nature of deep earthquakes is one of the big questions in geoscience," said Shirey. "We needed all four of these different disciplines to come together to make this argument. It turned out we had them all in-house at Carnegie."<p></p><p> </p><p> <br /><i><u><span style="font-family: times;">The above story is based on <span style="color: black;"><a href="https://carnegiescience.edu/news/what-causes-deep-earths-most-mysterious-earthquakes" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><span> </span>provided by<span> </span></span><a href="https://carnegiescience.edu/" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank"><b style="border-radius: 0px; box-sizing: border-box; font-weight: bold;">Carnegie Institution for Science</b></a></span></span></u></i></p>

Weird Water Dynamics Fuel Deep Earthquakes and Fist-Sized Diamonds

Photo Credit: Debswana Diamond Company   What causes the deep Earth's most mysterious earthquakes? The cause of Earth's deepest eart...

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Grain Size of Rocks in Earth's Mantle Affects Tectonics

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6Kc3gaIlaIzYUNNzDWaA45voVTo9Nj4Y5Kc32OpgpVvPbeaLHAaledZNLJVAFkbB0tZ-mtzNLQrRNLo2PbWiTQBAS_VyvCrp77LWU5UdB-5ojvkqzVi5KDN7_eBChBU5R3rcYI-eIisy3k4UhSVXCW4eUh15aIx4BU9LBmecfCEeF2KfAg8IZh0lb/s1418/grain-size-of-rocks-in%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="718" data-original-width="1418" height="324" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6Kc3gaIlaIzYUNNzDWaA45voVTo9Nj4Y5Kc32OpgpVvPbeaLHAaledZNLJVAFkbB0tZ-mtzNLQrRNLo2PbWiTQBAS_VyvCrp77LWU5UdB-5ojvkqzVi5KDN7_eBChBU5R3rcYI-eIisy3k4UhSVXCW4eUh15aIx4BU9LBmecfCEeF2KfAg8IZh0lb/w640-h324/grain-size-of-rocks-in%20(1).jpg" title="The simulation shows how the grain size of the mantle rocks develops when continents break apart along a so-called rift zone. Credit: Jonas Ruh / ETH Zurich" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">The simulation shows how the grain size of the mantle rocks develops when continents break apart along a so-called rift zone. Credit: Jonas Ruh / ETH Zurich</td></tr></tbody></table><br /><p></p><p style="text-align: left;">The planet is shaped by forces deep within its interior. These push the plates of the Earth's crust against each other, causing mountains and volcanoes to form along the collision zones. But when reconstructing what exactly is happening inside the Earth, we are limited to indirect observation; for example, by conducting pressure experiments on rocks from the Earth's mantle or by analyzing seismic waves triggered by earthquakes.<br /><br />Yet all these observations provide only snapshots. If we want to understand the dynamics of what has happened over several millions of years, we need computer models that can simulate geological processes in fast motion. By feeding the above-mentioned observational data and physical formulae into these models, researchers can show how the Earth's surface and interior change over time.<br /><br />There's a flaw here, though: every model is based on simplifications and is thus prone to error. Factors that may not seem particularly important at first glance can also turn out to play a key role, as a new study published in Nature Geoscience by the Structural Geology and Tectonics group at the ETH Department of Earth Sciences demonstrates. With their new simulations, the researchers are able to show that one crucial factor has not been adequately considered in previous models, even though it is known to have a potential effect: the grain size of the mantle rocks. The latest simulations now show how great the effect of grain size actually is.<br /></p><h4 style="text-align: left;"><span style="font-family: georgia;">Dislocation or diffusion?</span></h4><p style="text-align: left;">Grain size is relevant because it affects how the rocks deform in the upper mantle. If the grain size is in the range of a few millimeters, the minerals in the rocks deform mainly through the shifting of the minerals' crystal lattice along planes. This leads to what is known as dislocation creep, considered the most important mechanism of rock deformation in the Earth's mantle.<br /><br />If, on the other hand, the grain size is smaller, another mechanism becomes more important: diffusion creep. The rocks then deform, not by dislocations in the crystal lattice of the minerals, but by individual atomic vacancies in the crystal lattice migrating through the crystal structure. Depending on which deformation mechanism prevails, the strength of the rocks changes accordingly.<br /><br />"Fine-grained rocks are formed mainly in shear zones and are much weaker than the undeformed coarse-grained rocks," explains Jonas Ruh, senior assistant in the group and lead author of the study. "But until now, we haven't been able to realistically represent these differences in a dynamic model." Some of the previous models considered only dislocation creep, which is an oversimplification. Other models use constant grain sizes for the upper mantle rocks, which also does not do this factor justice.<br /><br />Ruh considered recent studies from other groups as well as laboratory experiments from his own research group for his new model. "Specifically, we incorporated a new growth model for the main mineral, olivine," he explains. "And, based on new research, we now also know that there is significantly less mechanical energy going into grain size reduction than previously thought." If these new findings are taken into account, the processes in the Earth's mantle can be modeled much more realistically.<br /></p><h4 style="text-align: left;"><span style="font-family: georgia;">Contradiction resolves itself</span></h4><p style="text-align: left;">Ruh was able to show that grain size reduction, the activation of diffusion creep, and the consequent weakening of the uppermost mantle significantly lowers the boundary forces needed to initiate rifting, and facilitates continental breakup.<br /><br />However, the new study was prompted by a different, seemingly paradoxical feature of plate tectonics: the uppermost region of the Earth's mantle must be relatively solid, as this is the only explanation for why tectonic plates that are pushed under another plate do not plunge into the depths at a steeper angle.<br /><br />But if this mantle region is as strong as the geometry of downgoing plates requires, the rocks in the uppermost mantle should be brittle in view of the major stresses that dominate there. It follows that there would have to be earthquakes in this area of the Earth's mantle that would release the stress in fits and starts. However, observations of such quakes have been extremely rare to date.<br /><br />The new model now resolves the paradox: "The fine-grained, ductile shear zones relieve the high stresses to the point where earthquakes can no longer occur," Ruh explains. "At the same time, the uppermost part of Earth's mantle remains strong enough to be consistent with observed flexure geometries of descending slabs in collision zones."</p><p><br /></p><p><i><u>The above story is based on <a href="https://www.nature.com/articles/s41561-022-00964-9" rel="nofollow" target="_blank">materials </a>provided by<a href="https://ethz.ch/en.html" rel="nofollow" target="_blank"> ETH Zurich.</a></u></i><br /></p>

Grain Size of Rocks in Earth's Mantle Affects Tectonics

The simulation shows how the grain size of the mantle rocks develops when continents break apart along a so-called rift zone. Credit: Jonas ...

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Yellowstone's History of Hydrothermal Explosions Over the Past 14,000 Years

<p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHOO82AXBvn6gfDSOsjN9wzG4WWX0HMaQg9R-gqX4Ybh7UPy3na9v13Y_YqlNi2b3HKZBjDhpXmckq6Uk0flI4ETn0cAp0-udxqbJfj_oQxIEYkVPn1IJZpEqtntfY_9ZM2EYvyFMnQuAgFJmjuijcpN8BVrdXxu1jOh0XYXoXThC2N_xAOOBz1niS/s1210/yellowstone-volcano-area-hit-by-biggest-earthquake-for-5-years%20(1).jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="807" data-original-width="1210" height="426" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHOO82AXBvn6gfDSOsjN9wzG4WWX0HMaQg9R-gqX4Ybh7UPy3na9v13Y_YqlNi2b3HKZBjDhpXmckq6Uk0flI4ETn0cAp0-udxqbJfj_oQxIEYkVPn1IJZpEqtntfY_9ZM2EYvyFMnQuAgFJmjuijcpN8BVrdXxu1jOh0XYXoXThC2N_xAOOBz1niS/w640-h426/yellowstone-volcano-area-hit-by-biggest-earthquake-for-5-years%20(1).jpg" title="Stock image showing a spring at Yellowstone National Park. GETTY IMAGES" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Stock image showing a spring at Yellowstone National Park.<br />GETTY IMAGES</td></tr></tbody></table> <br /></p><p>While much of public attention on Yellowstone focuses on its potential to produce large supereruptions, the hazards that are much more likely to occur are smaller, violent hydrothermal explosions. Hydrothermal explosions occur when near-boiling water suddenly flashes into steam, releasing large amounts of energy. The energy release fractures the rock downward, often leaving behind a crater. The same sources that can produce these explosions are what give Yellowstone its well-known hot springs, geysers, and fumaroles.<br /><br />The Yellowstone Lake area in Yellowstone National Park hosts at least eight large craters produced by hydrothermal explosions, including three of the largest hydrothermal explosion craters known on Earth. Compared to other areas of interest within Yellowstone, hydrothermal explosion craters have not been as thoroughly studied. In a new study published on Tuesday in GSA Bulletin, researchers evaluated the history of hydrothermal explosions at Yellowstone Lake over the past 14,000.<br /><br />"The hydrothermal system in Yellowstone is the largest in the world and is driven by high heat flow over a large area, by high precipitation rates, and by active seismicity and deformation. Over 10,000 hydrothermal features are present in Yellowstone," said Lisa Morgan, lead author of the study. "For this study, we wanted to know more about the recent geologic history of Yellowstone Lake and what role hydrothermal activity has had in the lake, especially the role of hydrothermal explosions and their triggering mechanisms."<br /><br />The research team collected sediment cores from across the northern portion of Yellowstone Lake and correlated them with cores that were previously collected in the vicinity, with the goal of characterizing their chemical and physical attributes and identifying hydrothermal explosion deposits in the cores.<br /><br />"Hydrothermal explosion sediments deposited underwater had never been described in published literature. In analyzing the cores, we made a lot of discoveries and had several surprises. Number one was how different the explosion deposits found in the cores looked from explosion deposits on land. That was to be expected since one was deposited through a water column and one was deposited on land," said Morgan.<br /><br />The researchers found evidence for at least 16 deposits in the cores that were produced by hydrothermal explosions. While 14 of the deposits represented more localized explosion events, two of the deposits were associated with two of Yellowstone's largest hydrothermal explosion craters: the Mary Bay and Elliott's craters.<br /><br />The Mary Bay hydrothermal explosion occurred 13,000 years ago and resulted in a 2.5-km (1.5-mi) wide crater, which is partly submerged under the lake. While deposits from the Mary Bay explosion exposed on land had been previously studied, the sediment cores from the lake demonstrated that the extent of its deposits was larger than previously thought and that the lake level must have been lower at the time of the explosion.<br /><br />The researchers concluded that the Mary Bay explosion was triggered by a sudden 14-m (46-ft) drop in lake level caused by a seismic event and a tsunami that eroded the outlet waterway of Yellowstone Lake.<br /><br />The Elliott's Crater explosion occurred 8,000 years ago and produced a 700-m (2,300-ft) wide crater. The crater is fully submerged underwater, and no deposits from the explosion are exposed on land. Based on records in the cores, the deposits from Elliott's Crater were also more broadly distributed than previously thought.<br /><br />Differing from how the Mary Bay Crater likely formed, the researchers determined that Elliott's Crater formed when a seismic event fractured the dome cap of the hydrothermal system. In Yellowstone Lake, hydrothermal domes form when underlying pockets of gas or gas-charged fluids cause overlying sediments to arch upwards. Rupturing this dome would result in a sudden loss of pressure, triggering a hydrothermal explosion.<br /><br />Many of the smaller deposits in the sediment cores were from previously unknown younger hydrothermal explosions. As has been consistent with previous studies of the explosion craters, there appears to be no relation between them and volcanic eruptions at Yellowstone.<br /><br />"Given what we see from Yellowstone Lake and elsewhere in Yellowstone, hydrothermal explosions of various scales will continue to occur," said Morgan.<br /></p><p><br /><i><u><span style="font-family: trebuchet;">The above story is based on <a href="https://www.geosociety.org/GSA/News/pr/2022/22-33.aspx" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><span> </span>provided by<span> </span></span><a href="https://www.geosociety.org/" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank"><strong style="border-radius: 0px !important; box-sizing: border-box; font-weight: bold;">Geological Society of America</strong></a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">.</span></span></u></i></p>

Yellowstone's History of Hydrothermal Explosions Over the Past 14,000 Years

Stock image showing a spring at Yellowstone National Park. GETTY IMAGES   While much of public attention on Yellowstone focuses on its poten...

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New Map Shows Earth’s Tectonic Plates In Unprecedented Detail

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjW1_XahgSgO9verrA6Yuz-mlYsKPSun4mcWkNJTzS36yP4tNlJ4qOk-zXT52i-WX8-c5Qa2CgWLJxJD_CvnrFnNwsLBR_aN-zm-BzYYzU3gazZsBTBWekO0NGmAh0Z7u6yfq-yDz763a_VYp7XJZWuC66b9K5pyqiieACNhzqgO6OmfuAFb3luqB0B/s1200/New%20Map%20Shows%20Earth%E2%80%99s%20Tectonic%20Plates%20In%20Unprecedented%20Detail%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="659" data-original-width="1200" height="352" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjW1_XahgSgO9verrA6Yuz-mlYsKPSun4mcWkNJTzS36yP4tNlJ4qOk-zXT52i-WX8-c5Qa2CgWLJxJD_CvnrFnNwsLBR_aN-zm-BzYYzU3gazZsBTBWekO0NGmAh0Z7u6yfq-yDz763a_VYp7XJZWuC66b9K5pyqiieACNhzqgO6OmfuAFb3luqB0B/w640-h352/New%20Map%20Shows%20Earth%E2%80%99s%20Tectonic%20Plates%20In%20Unprecedented%20Detail%20(1).jpg" title="New Map Shows Earth’s Tectonic Plates In Unprecedented Detail" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Credit: Dr. Derrick Hasterok, University of Adelaide</td></tr></tbody></table> <br /><p></p><p>New models that show how the continents were assembled are providing fresh insights into the history of the Earth and will help provide a better understanding of natural hazards like earthquakes and volcanoes.<br /><br />"We looked at the current knowledge of the configuration of plate boundary zones and the past construction of the continental crust," said Dr Derrick Hasterok, Lecturer, Department of Earth Sciences, University of Adelaide who led the team that produced the new models.<br /><br />"The continents were assembled a few pieces at a time, a bit like a jigsaw, but each time the puzzle was finished it was cut up and reorganised to produce a new picture. Our study helps illuminate the various components so geologists can piece together the previous images.<br /><br />"We found that plate boundary zones account for nearly 16 per cent of the Earth's crust and an even higher proportion, 27 per cent, of continents."<br /><br />The team produced three new geological models: a plate model, a province model and an orogeny model.<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />"There are 26 orogenies -- the process of mountain formation -- that have left an imprint on the present-day architecture of the crust. Many of these, but not all, are related to the formation of supercontinents," said Dr Hasterok.<br /><br />"Our work allows us to update maps of tectonic plates and the formation of continents that are found in classroom textbooks. These plate models which have been assembled from topographic models and global seismicity, have not been updated since 2003."<br /><br />The new plate model includes several new microplates including the Macquarie microplate which sits south of Tasmania and the Capricorn microplate that separates the Indian and Australian plates.<br /><br />"To further enrich the model, we added more accurate information about the boundaries of deformation zones: previous models showed these as discrete areas rather than wide zones," said Dr Hasterok.<br /><br />"The biggest changes to the plate model have been in western North America, which often has the boundary with the Pacific Plate drawn as the San Andreas and Queen Charlotte Faults. But the newly delineated boundary is much wider, approximately 1500 km, than the previously drawn narrow zone.<br /><br />"The other large change is in central Asia. The new model now includes all the deformation zones north of India as the plate bulldozes its way into Eurasia."<br /><br />Published in the journal Earth-Science Reviews, the team's work provides a more accurate representation of the Earth's architecture and has other important applications.<br /><br />"Our new model for tectonic plates better explains the spatial distribution of 90 per cent of earthquakes and 80 per cent of volcanoes from the past two million years whereas existing models only capture 65 per cent of earthquakes," said Dr Hasterok.<br /><br />"The plate model can be used to improve models of risks from geohazards; the orogeny model helps understand the geodynamic systems and better model Earth's evolution and the province model can be used to improve prospecting for minerals."<p></p><p> </p><p><u><i><span style="font-family: trebuchet;">The above story is based on <a href="https://www.adelaide.edu.au/newsroom/news/list/2022/06/07/updating-our-understanding-of-earths-architecture" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><span> </span>provided by<span> </span></span><a href="https://www.adelaide.edu.au/" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank"><b style="border-radius: 0px; box-sizing: border-box; font-weight: bold;">University of Adelaide</b></a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">. Original written by Crispin Savage.<span> </span></span></span></i></u> </p>

New Map Shows Earth’s Tectonic Plates In Unprecedented Detail

Credit: Dr. Derrick Hasterok, University of Adelaide   New models that show how the continents were assembled are providing fresh insights i...

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Scientists Discover “Ghost” Fossils – “Completely Unexpected”

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKotSwn7iXiSc2ZxhuetHwDNHJUVbCKHb3kNiHMx-8IgEG7MiMg11JVKMSXoQZdOg0ZfaJZ05-Kv2lVQr3nu0CHzEcYwxC7AemV6kvGTaNTrmqPXSxePvA3sqfEQewyA5jL6yYaUFK5XnVvvnbnf1ino11OIhTbobfWWBZdmNBGVNcI2flwcBdbscW/s1209/Microscopic-Plankton-Cell-Wall-Coverings-Preserved-As-Ghost-Fossil-Impressions%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1034" data-original-width="1209" height="549" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKotSwn7iXiSc2ZxhuetHwDNHJUVbCKHb3kNiHMx-8IgEG7MiMg11JVKMSXoQZdOg0ZfaJZ05-Kv2lVQr3nu0CHzEcYwxC7AemV6kvGTaNTrmqPXSxePvA3sqfEQewyA5jL6yYaUFK5XnVvvnbnf1ino11OIhTbobfWWBZdmNBGVNcI2flwcBdbscW/w640-h549/Microscopic-Plankton-Cell-Wall-Coverings-Preserved-As-Ghost-Fossil-Impressions%20(1).jpg" title="The images show the impressions of a collapsed cell-wall covering (a coccosphere) on the surface of a fragment of ancient organic matter (left) with the individual plates (coccoliths) enlarged to show the exquisite preservation of sub-micron-scale structures (right). Credit: S.M. Slater, P. Bown / Science journal" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: times;">The images show the impressions of a collapsed cell-wall covering (a coccosphere) on the surface of a fragment of ancient organic matter (left) with the individual plates (coccoliths) enlarged to show the exquisite preservation of sub-micron-scale structures (right). Credit: S.M. Slater, P. Bown / Science journal</span><br /></td></tr></tbody></table> <p></p><p><span style="font-family: georgia;">A previously unrecognized mode of fossilization of ancient microbes may explain how some of Earth’s oldest microfossils formed, according to new research.</span><br /></p><p>An international team of scientists from UCL (University College London), the Swedish Museum of Natural History, Natural History Museum (London) and the University of Florence have found a remarkable type of fossilisation that has remained almost entirely overlooked until now.<br /><br />The fossils are microscopic imprints, or "ghosts," of single-celled plankton, called coccolithophores, that lived in the seas millions of years ago, and their discovery is changing our understanding of how plankton in the oceans are affected by climate change.<br /><br />Coccolithophores are important in today's oceans, providing much of the oxygen we breathe, supporting marine food webs, and locking carbon away in seafloor sediments. They are a type of microscopic plankton that surround their cells with hard calcareous plates, called coccoliths, and these are what normally fossilize in rocks.<br /><br />Declines in the abundance of these fossils have been documented from multiple past global warming events, suggesting that these plankton were severely affected by climate change and ocean acidification. However, a study published today in the journal Science presents new global records of abundant ghost fossils from three Jurassic and Cretaceous warming events (94, 120 and 183 million years ago), suggesting that coccolithophores were more resilient to past climate change than was previously thought.<br /><br />"The discovery of these beautiful ghost fossils was completely unexpected," says Dr. Sam Slater from the Swedish Museum of Natural History. "We initially found them preserved on the surfaces of fossilized pollen, and it quickly became apparent that they were abundant during intervals where normal coccolithophore fossils were rare or absent -- this was a total surprise!"<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />Despite their microscopic size, coccolithophores can be hugely abundant in the present ocean, being visible from space as cloud-like blooms. After death, their calcareous exoskeletons sink to the seafloor, accumulating in vast numbers, forming rocks such as chalk.<br /><br />"The preservation of these ghost nannofossils is truly remarkable," says Professor Paul Bown (UCL). "The ghost fossils are extremely small -- their length is approximately five thousandths of a millimetre, 15 times narrower than the width of a human hair -- but the detail of the original plates is still perfectly visible, pressed into the surfaces of ancient organic matter, even though the plates themselves have dissolved away."<br /><br />The ghost fossils formed while the sediments at the seafloor were being buried and turned into rock. As more mud was gradually deposited on top, the resulting pressure squashed the coccolith plates and other organic remains together, and the hard coccoliths were pressed into the surfaces of pollen, spores and other soft organic matter. Later, acidic waters within spaces in the rock dissolved away the coccoliths, leaving behind just their impressions -- the ghosts.<br /><br />"Normally, palaeontologists only search for the fossil coccoliths themselves, and if they don't find any then they often assume that these ancient plankton communities collapsed," explains Professor Vivi Vajda (Swedish Museum of Natural History). "These ghost fossils show us that sometimes the fossil record plays tricks on us and there are other ways that these calcareous nannoplankton may be preserved, which need to be taken into account when trying to understand responses to past climate change."<br /><br />Professor Silvia Danise (University of Florence) says: "Ghost nannofossils are likely common in the fossil record, but they have been overlooked due to their tiny size and cryptic mode of preservation. We think that this peculiar type of fossilization will be useful in the future, particularly when studying geological intervals where the original coccoliths are missing from the fossil record."<br /><br />The study focused on the Toarcian Oceanic Anoxic Event (T-OAE), an interval of rapid global warming in the Early Jurassic (183 million years ago), caused by an increase in CO2-levels in the atmosphere from massive volcanism in the Southern Hemisphere. The researchers found ghost nannofossils associated with the T-OAE from the UK, Germany, Japan and New Zealand, but also from two similar global warming events in the Cretaceous: Oceanic Anoxic Event 1a (120 million years ago) from Sweden, and Oceanic Anoxic Event 2 (94 million years ago) from Italy.<br /><br />"The ghost fossils show that nannoplankton were abundant, diverse and thriving during past warming events in the Jurassic and Cretaceous, where previous records have assumed that plankton collapsed due to ocean acidification," explains Professor Richard Twitchett (Natural History Museum, London). "These fossils are rewriting our understanding of how the calcareous nannoplankton respond to warming events."<br /><br />Finally, Dr. Sam Slater explains: "Our study shows that algal plankton were abundant during these past warming events and contributed to the expansion of marine dead zones, where seafloor oxygen-levels were too low for most species to survive. These conditions, with plankton blooms and dead zones, may become more widespread across our globally warming oceans."<p></p><p> </p><p><u><i><span style="font-family: trebuchet;">The above story is based on <span style="color: black;"><a href="https://www.ucl.ac.uk/news/2022/may/discovery-ghost-fossils-reveals-plankton-resilience-past-global-warming-events" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><span> </span>provided by<span> </span></span><a href="https://www.ucl.ac.uk/" rel="noopener noreferrer nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; outline: currentcolor none 0px; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank"><b style="border-radius: 0px; box-sizing: border-box; font-weight: bold;">University College London</b></a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">.<span> </span></span></span></span></i></u> </p>

Scientists Discover “Ghost” Fossils – “Completely Unexpected”

The images show the impressions of a collapsed cell-wall covering (a coccosphere) on the surface of a fragment of ancient organic matter (le...

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Giant Magnetic Waves Have Been Discovered Oscillating Around Earth's Core

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZA6Ck5Y8wix-KMF85-KT5i5dHE1HZz0YSNviTvJrMPBbL8Mxuw9ZOLDjzLyhchDp9sJEMa0uhZdc6xMW6WTjUyv6bYlAugpBYvZZubYcihFs23kixlmCsQH-OjghTWjdf4RB2Wvpk6FSpJFtsGo6NOMC1VgyTkSZbSSY1zkY1Js7gHvdRS8I_f7uo/s1478/Magnetic_waves_across_Earth_s_outer_core_pillars%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="949" data-original-width="1478" height="410" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZA6Ck5Y8wix-KMF85-KT5i5dHE1HZz0YSNviTvJrMPBbL8Mxuw9ZOLDjzLyhchDp9sJEMa0uhZdc6xMW6WTjUyv6bYlAugpBYvZZubYcihFs23kixlmCsQH-OjghTWjdf4RB2Wvpk6FSpJFtsGo6NOMC1VgyTkSZbSSY1zkY1Js7gHvdRS8I_f7uo/w640-h410/Magnetic_waves_across_Earth_s_outer_core_pillars%20(1).jpg" title="Swarm satellites unveil magnetic waves that sweep the outermost part of Earth's outer core" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">This mysterious wave oscillates every seven years and propagates westward at up to 1500 kilometres a year. These waves align in columns along Earth’s axis of rotation. The motion and magnetic field changes associated with these waves are strongest near the equatorial region of the core. Credit: University Université Grenoble Alpes<br /></td></tr></tbody></table> <br /><p></p><p><span style="font-family: georgia;">Earth's interior is a far from quiet place. Deep below our surface activities, the planet rumbles with activity, from plate tectonics to convection currents that circulate through the hot magmatic fluids far underneath the crust.</span><br /></p><p>While volcanic eruptions and earthquakes serve as immediate reminders that Earth’s insides are anything but tranquil, there are also other, more elusive, dynamic processes happening deep down below our feet. Using information from ESA’s Swarm satellite mission, scientists have discovered a completely new type of magnetic wave that sweeps across the outermost part of Earth’s outer core every seven years. This fascinating finding, presented today at ESA’s Living Planet Symposium, opens a new window into a world we can never see.<br /></p><p>Earth’s magnetic field is like a huge bubble protecting us from the onslaught of cosmic radiation and charged particles carried by powerful winds that escape the Sun’s gravitational pull and stream across the Solar System. Without our magnetic field, life as we know it would not exist.<br /><br />Understanding exactly how and where our magnetic field is generated, why it fluctuates constantly, how it interacts with solar wind and, indeed, why it is currently weakening, is not only of academic interest but also of benefit to society. For example, solar storms can damage communication networks and navigation systems and satellites, so while we can’t do anything about changes in the magnetic field, understanding this invisible force helps to be prepared.<br /><br />Most of the field is generated by an ocean of superheated, swirling liquid iron that makes up Earth’s outer core 3000 km under our feet. Acting like the spinning conductor in a bicycle dynamo, it generates electrical currents and the continuously changing electromagnetic field.<br /></p><div style="margin: 0px auto; width: 100%;"> <script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <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> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div><br />ESA’s Swarm mission, which comprises three identical satellites, measures these magnetic signals that stem from Earth’s core, as well as other signals that come from the crust, oceans, ionosphere and magnetosphere.<br /><br />Since the trio of Swarm satellites were launched in 2013, scientists have been analysing their data to gain new insight into many of Earth’s natural processes, from space weather to the physics and dynamics of Earth’s stormy heart.<br /><br />Measuring our magnetic field from space is the only real way of probing deep down to Earth’s core. Seismology and mineral physics provide information about the material properties of the core, but they do not shed any light on the dynamo-generating motion of the liquid outer core.<br /><br />But now, using data from the Swarm mission, scientists have unearthed a hidden secret.<br /><br />A paper, published in the journal Proceedings of the National Academy of Sciences, describes how a team of scientists detected a new type of magnetic wave that sweeps across the ‘surface’ of Earth’s outer core – so where the core meets the mantle. This mysterious wave oscillates every seven years and propagates westward at up to 1500 kilometres a year.<br /><br />Nicolas Gillet, from the University Université Grenoble Alpes and lead author of the paper, said, “Geophysicists have long theorised over the existence of such waves, but they were thought to take place over much longer time scales than our research has shown.<br /><br />“Measurements of the magnetic field from instruments based on the surface of Earth suggested that there was some kind of wave action, but we needed the global coverage offered by measurements from space to reveal what is actually going on.<br /><br />“We combined satellite measurements from Swarm, and also from the earlier German Champ mission and Danish Ørsted mission, with a computer model of the geodynamo to explain what the ground-based data had thrown up – and this led to our discovery.”<br /><br />Owing to Earth’s rotation, these waves align in columns along the axis of rotation. The motion and magnetic field changes associated with these waves are strongest near the equatorial region of the core.<br /><br />While the research exhibits magneto-Coriolis waves near seven-year period, the question of the existence of such waves that would oscillate at different periods, however, remains.<br /><br />Dr Gillet added, “Magnetic waves are likely to be triggered by disturbances deep within the Earth's fluid core, possibly related to buoyancy plumes. Each wave is specified by its period and typical length-scale, and the period depends on characteristics of the forces at play. For magneto-Coriolis waves, the period is indicative of the intensity of the magnetic field within the core.<br /><br />“Our research suggests that other such waves are likely to exist, probably with longer periods – but their discovery relies on more research.”<br /><br />ESA’s Swarm mission scientist, Ilias Daras, noted, “This current research is certainly going to improve the scientific model of the magnetic field within Earth’s outer core. It may also give us new insight into the electrical conductivity of the lowermost part of the mantle and also of Earth’s thermal history.”<p></p><p> </p><p><span style="font-family: trebuchet;"><u><i>The above story is based on <a href="https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Swarm/Swarm_unveils_magnetic_waves_deep_down" rel="nofollow" target="_blank">materials </a>provided by<a href="https://www.esa.int/" rel="nofollow" target="_blank"> European Space Agency. </a></i></u></span><br /></p>

Giant Magnetic Waves Have Been Discovered Oscillating Around Earth's Core

This mysterious wave oscillates every seven years and propagates westward at up to 1500 kilometres a year. These waves align in columns alon...

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