Keyword: geology

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  • Why Do So Many Big Earthquakes Strike Japan?

    11/23/2016 11:45:55 AM PST · by JimSEA · 41 replies
    Live Science ^ | 11/22/2016 | Denise Chow
    A magnitude-6.9 earthquake struck yesterday off the coast of Fukushima, Japan, likely along the same fault that ruptured in 2011, unleashing a massive 9.0-magnitude temblor that triggered deadly tsunamis and caused widespread destruction. Over the course of its history, Japan has seen its share of shaking, but what makes this part of the world so susceptible to big earthquakes? The answer has to do with Japan's location. The island nation lies along the so-called Pacific Ring of Fire, an imaginary horseshoe-shaped zone that follows the rim of the Pacific Ocean, where many of the world's earthquakes and volcanic eruptions occur....
  • Rip in crust drives undersea volcanism

    11/16/2016 8:01:44 AM PST · by JimSEA · 26 replies
    Science Daily ^ | 11/14/2016 | Lamont-Doherty Earth Observatory
    Scientists analyzing a volcanic eruption at a mid-ocean ridge under the Pacific have come up with a somewhat contrarian explanation for what initiated it. Many scientists say undersea volcanism is triggered mainly by upwelling magma that reaches a critical pressure and forces its way up. The new study says the dominant force, at least in this case, was the seafloor itself -- basically that it ripped itself open, allowing the lava to spill out. The eruption took place on the East Pacific Rise, some 700 miles off Mexico. "Mid-ocean ridges are commonly viewed as seafloor volcanoes, operating like volcanoes on...
  • Popcorn-rocks solve the mystery of the magma chambers

    11/03/2016 7:41:36 AM PDT · by JimSEA · 9 replies
    Science Daily ^ | 11/2/2016 | Uppsala Universitet
    Since the 18th century, geologists have struggled to explain how big magma chambers form in Earth's crust. In particular, it has been difficult to explain where the surrounding rock goes when the magma intrudes. Now a team of researchers from Uppsala University and the Goethe University in Frankfurt have found the missing rocks -- and they look nothing like what they expected. Researchers have previously proposed that the roofs and walls of magma chamber were either melted and assimilated into the magma, or that they would sink to the bottom of the magma chamber. However, enough evidence for either of...
  • Tourists refused to flee erupting volcano so they could keep taking photos

    10/04/2016 5:43:41 PM PDT · by JimSEA · 38 replies
    Telegraph ^ | 10/3/2016 | Oliver Smith
    Tourists in Indonesia ignored instructions to flee an erupting volcano so they could continue taking photos, the country’s disaster agency has said. Mount Barujari, part of the Mount Rinjani National Park on the island of Lombok, erupted without warning last Tuesday, ejecting a column of ash two kilometres into the sky that subsequently delayed flights to and from nearby Bali. Indonesia’s Disaster Mitigation Agency quickly moved to evacuate the 1,023 tourists, including 639 foreigners, that were in the park at the time. It claims, however, that many refused to leave the mountain, in some cases even hiding from officials, so...
  • Life in ancient oceans enabled by erosion from land

    09/27/2016 2:27:11 PM PDT · by JimSEA · 12 replies
    Science Daily ^ | 9/28/2016 | University of Wisconsin-Madison
    As scientists continue finding evidence for life in the ocean more than 3 billion years ago, those ancient fossils pose a paradox. Organisms, including the single-celled bacteria living in the ocean at that early date, need a steady supply of phosphorus, but "it's very hard to account for this phosphorus unless it is eroding from the continents," says Aaron Satkoski, a scientist in the geoscience department at the University of Wisconsin-Madison. "So that makes it really hard to explain the fossils we see at this early era." Satkoski, who is first author of a new report on ocean chemistry from...
  • Oxygen levels were key to early animal evolution, strongest evidence now shows

    09/23/2016 3:50:31 PM PDT · by JimSEA · 64 replies
    Science Daily ^ | 9/23/2016 | University College London
    It has long puzzled scientists why, after 3 billion years of nothing more complex than algae, complex animals suddenly started to appear on Earth. Now, a team of researchers has put forward some of the strongest evidence yet to support the hypothesis that high levels of oxygen in the oceans were crucial for the emergence of skeletal animals 550 million years ago. The new study is the first to distinguish between bodies of water with low and high levels of oxygen. It shows that poorly oxygenated waters did not support the complex life that evolved immediately prior to the Cambrian...
  • Forget what you thought dinosaurs looked like — this adorable bird–lizard just changed the game

    09/16/2016 11:45:38 AM PDT · by JimSEA · 21 replies
    Business Insider ^ | 9/15/2016 | L. Dodgson
    Paleontologists have teamed up with a paleoartist to create a model which challenges everything you thought you knew about the typical dinosaur. Dr. Jacob Vinther ofa Psittacosaurus — nicknamed a "parrot-lizard" — is about the size of a turkey, has bristles on its tail and a birdlike beak. In other words, a bit weird, but also pretty cute. It's also quite likely that the animal had feathers and a horn on each cheek, the experts say. Quite aptly, Psittacosaurus belongs to the group ceratopsians, which basically means "horned faces" in Greek. It's the same group that contains Triceratops. The scientists...
  • Magma accumulation highlights growing threat from Japanese volcano

    09/14/2016 11:22:57 AM PDT · by JimSEA · 14 replies
    University of Bristol ^ | 9/13/2016 | University of Bristol
    A research team led by the University of Bristol has found magma build-up beneath Japan's Aira caldera and Sakurajima volcano may indicate a growing threat to Kagoshima city and its 600,000 inhabitants. Sakurajima is one of Japan's most active volcanoes with small, localised eruptions nearly every day, but the history of the volcano is even more ferocious. In 1914, a large explosive eruption killed 58 people and caused widespread flooding in the adjacent city of Kagoshima as the ground subsided due to the withdrawal of magma from the subsurface. Continued measurements of the ground movement since that eruption show that...
  • Life thrived on young Earth: scientists discover 3.7-billion-year-old fossils

    08/31/2016 4:24:39 PM PDT · by JimSEA · 53 replies
    Science Daily ^ | 8/31/2016 | Allen P. Nutman, et al
    In an extraordinary find, a team of Australian researchers have uncovered the world's oldest fossils in a remote area of Greenland, capturing the earliest history of the planet and demonstrating that life on Earth emerged rapidly in the planet's early years. Led by the University of Wollongong's (UOW) Professor Allen Nutman, the team discovered 3.7-billion-year-old stromatolite fossils in the world's oldest sedimentary rocks, in the Isua Greenstone Belt along the edge of Greenland's icecap. The findings are outlined in a study published in Nature, with co-authors Associate Professor Vickie Bennett from The Australian National University (ANU), the University of New...
  • Evidence from China shows how plants colonized the land

    08/10/2016 10:15:05 AM PDT · by JimSEA · 14 replies
    Science Daily ^ | 8/8/2016 | University of Bristol
    New fossil finds from China push back the origins of deep soils by 20 million years, new research has uncovered. This is a key part of the stepwise conquest of the land and transformation of the continents, researchers from the universities of Peking and Bristol have discovered. One of the greatest transitions in Earth history was the greening of the land. Up to 450 million years ago, there was no life outside water, and the land surface was a rocky landscape. Without plants there were no soils, and the rocky landscape eroded fast. Then the first tiny plants crept out...
  • Illustrating Geology: Great images that transformed the field

    07/31/2016 7:47:42 AM PDT · by JimSEA · 2 replies
    Earth ^ | 7/17/2016 | Timothy Oleson
    Last year marked the 200th anniversary of the publication of what many consider the greatest geologic image ever produced: William Smith’s epic map, entitled “A Delineation of the Strata of England and Wales with Part of Scotland.” In striking color, scale and detail, the 1815 map laid bare the region’s bedrock — from tilted layers of slate and fossil-rich marls and sandstones to Carboniferous coal seams and granite plugs — as none had before. The bicentennial of the map’s publication was commemorated in several sessions and displays at the annual meeting of the Geological Society of America (GSA) in Baltimore...
  • Rare Earthquake Strikes Off the Coast of Florida

    07/17/2016 12:02:52 PM PDT · by SoFloFreeper · 45 replies
    weather.com ^ | 7/17/16 | Pam Wright
    A small but rare earthquake struck about 100 miles off Daytona Beach, Florida, in the Atlantic Ocean, reports the Associated Press. According to the U.S. Geological Survey, the magnitude 3.7 earthquake struck around 4 p.m. Saturday. There are no reports of damage or that it was felt on land. ...The USGS says earthquakes of less than magnitude 5.4 rarely cause damage. There are about 930,000 such quakes recorded worldwide each year or about 2,500 per day. According to the Florida’s Department Environmental Protection, the sunshine state sits on a section of the North American Plate that is less active than...
  • Did a supernova two million years ago brighten the night sky and give our ancestors cancer?

    06/17/2016 4:22:29 PM PDT · by rickmichaels · 39 replies
    Daily Mail ^ | June 17, 2016 | Cheyenne Macdonald
    Millions of years ago, a series of nearby supernovae sent radiation and debris raining down to Earth. The events left traces of radioactive iron-60 embedded in the sea floor and even on the Moon, and now, researchers are saying they may have had life-altering effects on the early inhabitants of our planet. At just hundreds of light-years away, two major stellar explosions may have spurred changes to the environment, and even increased the rates of cancer and mutation.
  • Large-scale motion detected near San Andreas Fault System

    06/21/2016 9:53:56 AM PDT · by Red Badger · 34 replies
    UPI ^ | June 20, 2016 at 2:03 PM | By Brooks Hays
    The top diagram shows the lobes of movement, uplift in red and subsidence in blue, found using GPS data, while the botom diagram shows the lobes predicted by an earthquake simulation model. Image by University of Hawaii, Manoa =============================================================================================== HONOLULU, June 20 (UPI) -- Analysis of GPS data has revealed new areas of motion around the San Andreas Fault System. Using data collected by the EarthScope Plate Boundary Observatory's GPS array, researchers identified 125-mile-wide "lobes" of uplift and subsidence. Over the last several years, the lobes, which straddle the fault line, have hosted a few millimeters of annual movement. Computer...
  • Marine life quickly recovered after global mass extinction

    06/17/2016 9:19:33 AM PDT · by JimSEA · 24 replies
    Science Daily ^ | 6/17/2016 | Becky Oskin
    Reptiles rapidly invaded the seas soon after a global extinction wiped out most life on Earth, according to a new study led by University of California, Davis, researchers. Global climate change -- likely triggered by massive volcanic eruptions -- killed off more than 95 percent of all species about 250 million years ago, at the end of the Permian period. Land reptiles colonized the ocean in just 3.35 million years at the beginning of the Triassic, a speedy recovery in geologic time, the researchers report in the journal Scientific Reports. "Our results fit with the emerging view that the recovery...
  • Climate change mitigation: Turning carbon dioxide into rock

    06/12/2016 3:21:39 PM PDT · by JimSEA · 28 replies
    Science Daily ^ | 6/9/2016 | University of Southampton
    An international team of scientists have found a potentially viable way to remove anthropogenic (caused or influenced by humans) carbon dioxide emissions from the atmosphere -- turn it into rock. The study, published in Science, has shown for the first time that the greenhouse gas carbon dioxide (CO2) can be permanently and rapidly locked away from the atmosphere, by injecting it into volcanic bedrock. The CO2 reacts with the surrounding rock, forming environmentally benign minerals. Measures to tackle the problem of increasing greenhouse gas emissions and resultant climate change are numerous. One approach is Carbon Capture and Storage (CCS), where...
  • Deep 'scars' from ancient geological events play role in current earthquakes

    06/10/2016 4:36:30 PM PDT · by JimSEA · 21 replies
    Science Daily ^ | 6/10/2016 | Philip J. Heron, et al
    Super-computer modelling of Earth's crust and upper-mantle suggests that ancient geologic events may have left deep 'scars' that can come to life to play a role in earthquakes, mountain formation, and other ongoing processes on our planet. This changes the widespread view that only interactions at the boundaries between continent-sized tectonic plates could be responsible for such events. A team of researchers from the University of Toronto and the University of Aberdeen have created models indicating that former plate boundaries may stay hidden deep beneath the Earth's surface. These multi-million-year-old structures, situated at sites away from existing plate boundaries, may...
  • The most dangerous fault in America

    06/07/2016 8:52:55 AM PDT · by JimSEA · 34 replies
    Earth ^ | May, 2016 | Steven Newton
    Last summer, a startling article appeared in The New Yorker magazine outlining what could happen to the Pacific Northwest in the event of a large earthquake resulting from a full rupture of the Cascadia Subduction Zone. As recently as 1700, this convergent zone produced an earthquake estimated at magnitude 9. The article attracted a great deal of attention, especially among people who had never heard of the possibility that the heavily populated Pacific Northwest could, in a geologic moment, become “toast” — as someone quoted in the article put it. The San Francisco Bay Area also suffers from the unfortunate...
  • Here are the world’s top 10 gold producing mines

    06/07/2016 7:26:42 AM PDT · by JimSEA · 19 replies
    Mining.com ^ | 6/4/2016 | Frank Holmes
    Gold output across the globe hit an all-time high in 2015, climbing 1.8 percent to 3,211 tonnes. Much of this growth was led by Mexico, whose output increased double digits (18 percent) from 112 tonnes in 2014 to 133 tonnes last year. Indonesia grew 20 percent, Kazakhstan 29 percent. This year, global production is expected to level out as project development budgets were slashed during the three-year gold bear market. But with gold prices rebounding, miners are in a good position to be much more profitable. Below, explore and discover the world’s top 10 gold producing mines.
  • Supervolcanoes like Yellowstone may have been more active in the past

    06/04/2016 11:13:08 AM PDT · by JimSEA · 22 replies
    National Science Foundation ^ | 6/2/2016 | Carol Frost, Davin Bagdonas
    Magma located under areas that include the Yellowstone region and the western margin of North and South America can erupt violently, spewing vast quantities of ash into the air, followed by slower flows of glassy, viscous magma. [A] new study by University of Wyoming researchers suggests scientists can go back to the past to study present-day solidified magma chambers where the erosion has removed overlying rock, exposing granite underpinnings. One such large granite body, the 2.62 billion-year-old Wyoming batholith, extends more than 125 miles across central Wyoming. University of Wyoming earth scientist Davin Bagdonas traversed the Granite, Shirley and Laramie...
  • Volcanic activity worldwide 1 Jun 2016:

    06/02/2016 12:33:24 PM PDT · by JimSEA · 10 replies
    Volcano Discovery Blog ^ | Various | Dr. Tom Pfeiffer
    Volcanic activity worldwide 1 Jun 2016: Colima volcano, Bromo, Semeru, Dukono, Turrialba, Nyiragongo...
  • Archaeologists and geographers team to predict locations of ancient Buddhist sites [Ashoka's Edicts]

    05/31/2016 3:51:48 PM PDT · by SunkenCiv · 10 replies
    UCLA ^ | May 26, 2016 | Jessica Wolf
    For archaeologists and historians interested in the ancient politics, religion and language of the Indian subcontinent, two UCLA professors and their student researchers have creatively pinpointed sites that are likely to yield valuable transcriptions of the proclamations of Ashoka, the Buddhist king of northern India's Mauryan Dynasty who ruled from 304 B.C. to 232 B.C. In a study published this week in Current Science, archaeologist Monica Smith and geographer Thomas Gillespie identified 121 possible locations of what are known as Ashoka's "edicts." First they isolated shared features of 29 known locations of Ashokan edicts, which were found carved into natural...
  • Looking for a geologist.

    05/20/2016 7:32:16 PM PDT · by M.K. Borders · 22 replies
    Request for info | 20 May 216 | Myself
    Looking for a geologist with knowledge of Oklahoma in general and specifically the area surrounding Fort Sill.
  • Scientists find likely cause for recent southeast U.S. earthquakes

    05/17/2016 7:44:53 AM PDT · by JimSEA · 8 replies
    AGU Blogosphere ^ | 5/5/2016 | Ilipuma
    The southeastern United States should, by all means, be relatively quiet in terms of seismic activity. It’s located in the interior of the North American Plate, far away from plate boundaries where earthquakes usually occur. But the area has seen some notable seismic events – most recently, the 2011 magnitude-5.8 earthquake near Mineral, Virginia that shook the nation’s capital. Now, scientists report in a new study a likely explanation for this unusual activity: pieces of the mantle under this region have been periodically breaking off and sinking down into the Earth. This thins and weakens the remaining plate, making it...
  • Clues to ancient giant asteroid found in Australia

    05/16/2016 8:53:57 AM PDT · by JimSEA · 8 replies
    Science Daily ^ | 5/16/2016 | Australian National University
    Scientists have found evidence of a huge asteroid that struck the Earth early in its life with an impact larger than anything humans have experienced. Tiny glass beads called spherules, found in north-western Australia were formed from vaporised material from the asteroid impact, said Dr Andrew Glikson from The Australian National University (ANU). "The impact would have triggered earthquakes orders of magnitude greater than terrestrial earthquakes, it would have caused huge tsunamis and would have made cliffs crumble," said Dr Glikson, from the ANU Planetary Institute. "Material from the impact would have spread worldwide. These spherules were found in sea...
  • Cosmic dust reveals Earth's ancient atmosphere

    05/12/2016 10:00:37 AM PDT · by JimSEA · 22 replies
    Science Daily ^ | 5/11/2016 | Monash University
    Using the oldest fossil micrometeorites -- space dust -- ever found, Monash University-led research has made a surprising discovery about the chemistry of Earth's atmosphere 2.7 billion years ago. The findings of a new study published today in the journal Nature -- led by Dr Andrew Tomkins and a team from the School of Earth, Atmosphere and Environment at Monash, along with scientists from the Australian Synchrotron and Imperial College, London -- challenge the accepted view that Earth's ancient atmosphere was oxygen-poor. The findings indicate instead that the ancient Earth's upper atmosphere contained about the same amount of oxygen as...
  • Ancient tectonic activity was trigger for ice ages

    04/19/2016 2:48:05 PM PDT · by JimSEA · 19 replies
    Science Daily ^ | 4/19/2016 | Oliver Jagoutz, Francis A. Macdonald, Leigh Royden
    For hundreds of millions of years, Earth's climate has remained on a fairly even keel, with some dramatic exceptions: Around 80 million years ago, the planet's temperature plummeted, along with carbon dioxide levels in the atmosphere. The Earth eventually recovered, only to swing back into the present-day ice age 50 million years ago. Now geologists at MIT have identified the likely cause of both ice ages, as well as a natural mechanism for carbon sequestration. Just prior to both periods, massive tectonic collisions took place near the Earth's equator -- a tropical zone where rocks undergo heavy weathering due to...
  • Links within two supercontinents

    04/12/2016 3:00:55 PM PDT · by JimSEA · 20 replies
    Science Daily ^ | 4/12/2016 | University of Wyoming
    A University of Wyoming researcher contributed to a paper that has apparently solved an age-old riddle of how constituent continents were arranged in two Precambrian supercontinents -- then known as Nuna-Columbia and Rodinia. It's a finding that may have future economic implications for mining companies. Specifically, the article describes a technique Kevin Chamberlain, a UW research professor in the Department of Geology and Geophysics, and other researchers used to test reconstructions of ancient continents. The paper argues that the rocks or crust now exposed in southern Siberia were once connected to northern North America for nearly a quarter of the...
  • UW Study: Ancient Rocks of Tetons Formed by Continental Collisions

    04/10/2016 8:19:28 AM PDT · by JimSEA · 22 replies
    University of Wyoming ^ | 2/1/2016 | University of Wyoming
    February 1, 2016 — University of Wyoming scientists have found evidence of continental collisions in Wyoming’s Teton Range, similar to those in the Himalayas, dating to as early as 2.68 billion years ago. The research, published Jan. 22 in the journal Geochimica et Cosmochimica Acta, shows that plate tectonics were operating in what is now western Wyoming long before the collisions that created the Himalayas starting 40 million years ago. In fact, the remnants of tectonic activity in old rocks exposed in the Tetons point to the world’s earliest known continent-continent collision, says Professor Carol Frost of UW’s Department of...
  • Astronomy Picture of the Day -- Earth's Richat Structure

    05/19/2013 6:05:54 AM PDT · by SunkenCiv · 26 replies
    NASA ^ | May 19, 2013 | (see photo credit)
    Explanation: What on Earth is that? The Richat Structure in the Sahara Desert of Mauritania is easily visible from space because it is nearly 50 kilometers across. Once thought to be an impact crater, the Richat Structure's flat middle and lack of shock-altered rock indicates otherwise. The possibility that the Richat Structure was formed by a volcanic eruption also seems improbable because of the lack of a dome of igneous or volcanic rock. Rather, the layered sedimentary rock of the Richat structure is now thought by many to have been caused by uplifted rock sculpted by erosion. The above image...
  • Geology Picture of the Week, March 12-18, 2006: Northwest Angle and Lake of the Woods

    03/13/2006 12:21:19 PM PST · by cogitator · 9 replies · 334+ views
    Today's two images are inspired by the "learn something new every day" phenomenon. In this case, the something that was learned was about the Northwest Angle in Minnesota, pictured here (click to go to article, with larger image link). I wanted to find other images of the Northwest Angle, but couldn't find much. However, I did find the interesting site below, with a virtual tour and smallish excerpts from a Landsat poster of Lake of the Woods. The image below was interesting, especially the circularity of the features in the lower part of the image. A Virtual Tour of Lake...
  • Geology Picture of the Week, June 23-30, 2002

    06/26/2002 8:56:25 AM PDT · by cogitator · 14 replies · 574+ views
    Richat Structure, Mauritania This prominent circular feature in the Sahara desert of Mauritania has attracted attention since the earliest space missions because it forms a conspicuous bull’s-eye in the otherwise rather featureless expanse of the desert. Described by some as looking like an outsized ammonite in the desert, the structure [which has a diameter of almost 50 kilometers (30 miles)] has become a landmark for shuttle crews. Initially interpreted as a meteorite impact structure because of its high degree of circularity, it is now thought to be merely a symmetrical uplift (circular anticline) that has been laid bare by...
  • We Finally Know How Much the Dino-Killing Asteroid Reshaped Earth

    03/22/2016 10:32:51 AM PDT · by JimSEA · 48 replies
    Smithsonian ^ | 2/25/2016 | Jane Palmer
    More than 65 million years ago, a six-mile wide asteroid smashed into Mexico's Yucatán peninsula, triggering earthquakes, tsunamis and an explosion of debris that blanketed the Earth in layers of dust and sediment. Now analysis of commercial oil drilling data—denied to the academic community until recently—offers the first detailed look at how the Chicxulub impact reshaped the Gulf of Mexico. Figuring out what happened after these types of impacts gives researchers a better idea of how they redistribute geological material around the world. It also gives scientists an idea of what to expect if another such impact were to occur...
  • Geologists discover how Australia's highest mountain was created

    03/16/2016 12:21:20 PM PDT · by JimSEA · 35 replies
    Science Daily ^ | 3/16/2016 | University of Sydney
    Geologists from the University of Sydney and the California Institute of Technology have solved the mystery of how Australia's highest mountain -- Mount Kosciuszko -- and surrounding Alps came to exist. Most of the world's mountain belts are the result of two continents colliding (e.g. the Himalayas) or volcanism. The mountains of Australia's Eastern highlands -- stretching from north-eastern Queensland to western Victoria -- are an exception. Until now no one knew how they formed. A research team spearheaded by Professor Dietmar Müller from the University's School of Geosciences used high performance computing code to investigate the cause of the...
  • Characterizing Interglacial Periods over the Past 800,000 Years

    03/06/2016 6:41:39 PM PST · by JimSEA · 49 replies
    EOS ^ | 3/2/16 | Cody Sullivan
    Global climate patterns have undergone a remarkable shift in the past 600,000 to 1.2 million years. Before the transition, glacial cycles, consisting of cold ice ages and milder interludes, typically lasted about 40,000 years—but those weaker cycles gave way to longer-lasting icy eras with cycles lasting roughly 100,000 years. In between the cold ice ages are periods of thawing and warming known as interglacial periods, during which sea levels rise and ice retreats. Here Past Interglacials Working Group of PAGES identifies and compares interglacial periods over the past 800,000 years, including our current era. Glacial periods give way to interglacials...
  • Breaking the Strongest Link Triggered Big Baja Earthquake

    03/01/2016 6:40:24 AM PST · by JimSEA · 2 replies
    UC Davis ^ | 2/15/16 | Becky Oskin
    spate of major earthquakes on small faults could overturn traditional views about how earthquakes start, according to a study from researchers at the Centro de Investigación Científica y de Educación Superior in Ensenada, Mexico, and the University of California, Davis. In the past 25 years, many of California’s biggest earthquakes struck on small faults, away from the San Andreas Fault plate boundary. These events include the Landers, Hector Mine and Napa earthquakes. Several of the quakes were unexpected, rattling areas thought seismically quiet. A closer look at one of the surprise events, the magnitude-7.2 El Mayor-Cucapah earthquake, showed that small...
  • Ropoto: A town in Greece lost to a landslide

    02/29/2016 3:44:07 PM PST · by JimSEA · 10 replies
    AGU Blogosphere ^ | 2/23/16 | dr-dave
    Ropoto in Greece In the last week a few media outlets (such as Atlas Obscura) have carried reports about the town of Ropoto in Greece, which in 2010 was abandoned due to a landslide, inspired by an article on the Greek Explorer website. The latter has made a short documentary about the town, and its landslide. The short description that goes with the film is as follows: Ropoto was once a thriving village and home to 300 families, but a landslide in 2012 turned the village into a ghost town. Today, forgotten by people and authorities, Ropoto’s terrain is still...
  • New evidence about the Gulf of Mexico's past

    02/21/2016 12:39:48 PM PST · by JimSEA · 10 replies
    Science Daily ^ | 2/16/2016 | University of HoustoN
    Geologists studying a region in the Mexican state of Veracruz have discovered evidence to explain the origin of the Wilcox Formation, one of Mexico's most productive oil plays, as well as support for the theory that water levels in the Gulf of Mexico dropped dramatically as it was separated from the rest of the world's oceans and Earth entered a period of extreme warming. The drop in water levels and the warming, known as the Paleocene-Eocene thermal maximum (PETM), occurred around 55.8 million years ago. The Gulf refilled about 850,000 years later. Van Nieuwenhuise, director of professional geoscience programs at...
  • Can slow creep along thrust faults help forecast megaquakes?

    02/06/2016 10:36:54 AM PST · by JimSEA · 9 replies
    Science Daily ^ | 2/4/2016 | University of California
    In Japan and areas like the Pacific Northwest where megathrust earthquakes are common, scientists may be able to better forecast large quakes based on periodic increases and decreases in the rate of slow, quiet slipping along the fault. This hope comes from a new study by Japanese and UC Berkeley seismologists, looking at the more than 1,000-kilimeter-long fault off northeast Japan where the devastating 2011 Tohoku-oki earthquake originated, generating a tsunami that killed thousands. There, the Pacific Plate is trundling under the Japan plate, not only causing megaquakes like the magnitude 9 in 2011, but giving rise to a chain...
  • Icy ebb and flow influenced by hydrothermal activity

    02/03/2016 8:26:28 AM PST · by JimSEA · 14 replies
    Science Daily ^ | 1/29/2016 | Univ of Connecticut
    Hydrothermal activity along the mid-ocean ridge system suggests that the release of molten rock, or magma, in response to changes in sea level plays a significant role in the earth's climate. The last million years of Earth's history was dominated by the cyclic advance and retreat of ice sheets over large swaths of North America. During cold glacial intervals, ice sheets reached as far south as Long Island and Indiana, while during warm interglacial periods the ice rapidly retreated to Greenland. It has long been known that ice ages occur every 40,000 years or so, but the cause of rapid...
  • Ancient rocks of Tetons formed by continental collisions

    02/01/2016 2:13:19 PM PST · by JimSEA · 36 replies
    Science Daily ^ | 1/29/2016 | Univ. of Wyoming
    University of Wyoming scientists have found evidence of continental collisions in Wyoming's Teton Range, similar to those in the Himalayas, dating to as early as 2.68 billion years ago. The research, published Jan. 22 in the journal Geochimica et Cosmochimica Acta, shows that plate tectonics were operating in what is now western Wyoming long before the collisions that created the Himalayas starting 40 million years ago. In fact, the remnants of tectonic activity in old rocks exposed in the Tetons point to the world's earliest known continent-continent collision, says Professor Carol Frost of UW's Department of Geology and Geophysics, lead...
  • New study zeros in on plate tectonics' start date

    01/25/2016 10:35:42 AM PST · by JimSEA · 28 replies
    Science Daily ^ | 1/21/2016 | University of Maryland
    Earth has some special features that set it apart from its close cousins in the solar system, including large oceans of liquid water and a rich atmosphere with just the right ingredients to support life as we know it. Earth is also the only planet that has an active outer layer made of large tectonic plates that grind together and dip beneath each other, giving rise to mountains, volcanoes, earthquakes and large continents of land. Geologists have long debated when these processes, collectively known as plate tectonics, first got underway. Some scientists propose that the process began as early as...
  • The Backwards Earthquakes

    12/19/2015 10:02:24 AM PST · by JimSEA · 29 replies
    Eos.org ^ | 12/15/2016 | Erin Ross
    Earthquakes in Idaho's panhandle are usually caused by the Earth's crust pulling apart. So why were earthquakes on 24 April pushing the crust together? Last April, a swarm of earthquakes shook the ground near Sandpoint, Idaho. Unused to shaking, Sandpoint’s residents took notice. So did local media, widely reporting on the events. But it wasn’t the size or location of the earthquakes that surprised scientists. Sandpoint lies along the Lewis and Clark Fault Zone, and previous earthquakes in the region were caused when the Earth’s crust pulled apart, which geologists call extension. But the earthquakes that struck on 24 April...
  • Plate tectonics thanks to plumes?

    11/12/2015 9:11:35 AM PST · by JimSEA · 7 replies
    Science Daily ^ | November 11, 2015 | ETH Zurich
    "Knowing what a chicken looks like and what all the chickens before it looked like doesn't help us to understand the egg," says Taras Gerya. The ETH Professor of Geophysics uses this metaphor to address plate tectonics and the early history of the Earth. The Earth's lithosphere is divided into several plates that are in constant motion, and today's geologists have a good understanding of what drives these plate movements: heavier ocean plates are submerged beneath lighter continental plates along what are known as subduction zones. Once the movement has begun, it is perpetuated due to the weight of the...
  • Could Mount St Helens be about to erupt? Massive magma chamber found below the volcano ...

    11/05/2015 10:25:45 AM PST · by Red Badger · 111 replies
    www.dailymail.co.uk ^ | 12:49 EST, 5 November 2015 | By Richard Gray
    Geologists have discovered a second magma chamber beneath volcano They believe this feeds the smaller chamber directly below the mountain Earthquakes in the area may be a sign of magma pumping between them Geologists still consider Mount St Helens to be of high risk of erupting Its scarred and jagged crater is a reminder of the terrible devastation that Mount St Helens wrought over the Washington countryside 35 years ago. Now a new study of the volcanic plumbing lurking beneath the 8,363ft (2,459 metre) summit suggests the volcano could yet again blow its top in an explosive eruption. Geologists studying...
  • Supervolcanoes likely triggered externally

    11/05/2015 9:03:26 AM PST · by JimSEA · 42 replies
    Science Daily ^ | November 4, 2015 | University of Illinois at Urbana-Champaign
    Supervolcanoes, massive eruptions with potential global consequences, appear not to follow the conventional volcano mechanics of internal pressure building until the volcano blows. Instead, a new study finds, such massive magma chambers might erupt when the roof above them cracks or collapses. Knowledge of triggering mechanisms is crucial for monitoring supervolcano systems, including ones that lie beneath Yellowstone National Park and Long Valley, California, according to the study led by Patricia Gregg, University of Illinois professor of geology, in collaboration with professor Eric Grosfils of Pomona College and professor Shan de Silva of Oregon State University. The study was published...
  • Large igneous provinces linked to extinction events

    10/30/2015 12:22:44 PM PDT · by JimSEA · 34 replies
    Science Daily ^ | October 30, 2015 | Geological Society of America
    Mass extinction events are sometimes portrayed in illustrations of volcanic eruptions causing widespread destruction. According to Dr. Richard E. Ernst of Carleton University, Ottawa, Canada, expert on Large Igneous Provinces (LIPs), this interpretation may have some truth behind it, but not in the instantaneous way we might think. Ernst will report on his research on 1 November at the Geological Society of America's Annual Meeting in Baltimore, Maryland, USA. The basaltic lava flowing from ancient volcanoes and the portion of magma (liquid rock) emplaced underground can create geologic conditions linked with climate change and, subsequently, extinction events. This climatic effect...
  • New 'geospeedometer' confirms super-eruptions have short fuses

    10/22/2015 11:52:24 AM PDT · by JimSEA · 32 replies
    Science Daily ^ | October 20, 2015 | Vanderbilt University
    Repeatedly throughout Earth's history, giant pools of magma greater than 100 cubic miles in volume have formed a few miles below the surface. They are the sources of super-eruptions -- gigantic volcanic outbursts that throw 100 times more superheated gas, ash and rock into the atmosphere than run-of-the-mill eruptions, enough to blanket continents and plunge the globe into decades-long volcanic winters. Now a team of geologists have developed a new "geospeedometer" that they argue can help resolve this controversy by providing direct measurements of how long the most explosive types of magma existed as melt-rich bodies of crystal-poor magma before...
  • Earth's inner core was formed 1-1.5 billion years ago

    10/11/2015 12:03:37 PM PDT · by JimSEA · 38 replies
    Science Daily ^ | 10/7/2015 | University of Liverpool
    There have been many estimates for when the earth's inner core was formed, but scientists from the University of Liverpool have used new data which indicates that the Earth's inner core was formed 1 -- 1.5 billion years ago as it "froze" from the surrounding molten iron outer core. . . . . In a new study published in Nature, researchers from the University's School of Environmental Sciences analysed magnetic records from ancient igneous rocks and found that there was a sharp increase in the strength of the Earth's magnetic field between 1 and 1.5 billion years ago. This increased...
  • Geologists Discover New Layer in Earth’s Mantle

    09/25/2015 2:28:37 PM PDT · by JimSEA · 79 replies
    Sci-News.com ^ | 9/24/2015 | Staff
    New research led by Dr Hauke Marquardt of the University of Bayreuth, Germany, suggests the existence of a previously unknown superviscous layer inside our planet: part of the lower mantle where the rock gets 3 times stiffer. Such a layer may explain why tectonic plate slabs seem to pool at 930 miles (1,500 km) under Indonesia and South America’s Pacific coast. “The Earth has many layers, like an onion. Most layers are defined by the minerals that are present. Essentially, we have discovered a new layer in the Earth. This layer isn’t defined by the minerals present, but by the...