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The Ultimate Stress Reliever

Reporting in the journal Science, researchers say they’ve discovered a surprising wrinkle in the geologic story behind one of the most devastating earthquakes in recent memory: the March 2011 Tohoku earthquake that spawned 130-foot tsunami waves, killed 15,800 people and led to a crisis at the Fukushima Daiichi nuclear power plant. The researchers determined that current shear stress on the fault that generated the earthquake is nearly zero. In other words, the violent spasm that released the earthquake also shook out all the pent up stress on the fault. Alan McStravick, writing in a recent article for the website Red Orbit, explained why this was such a shocker: “The paper’s presentation of this fact flies in the face of the prevailing wisdom that earthquakes will typically only release a portion of … Read entire article »

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Earthquake Signals Tectonic Plate Ripping Apart

Three papers in this week’s issue of the journal Nature present startling new findings about an earthquake that struck the Indian Ocean off the coast of Sumatra last April. As reported by Andrea Mustain at Our Amazing Planet, three features of the quake made it unusual: First, it was extremely powerful—at magnitude 8.7, it was the sixth most powerful ever recorded. Second, it struck in the middle of a tectonic plate and not along a plate boundary. Third, when the quake zipped along the initial fault and ran into faults intersecting it at right angles, those intersecting faults ruptured too. Mustain interviewed Thorne Lay, a professor at the University of California, Santa Cruz and co-author of one of the papers: Lay said that, typically, when earthquakes spread to connecting faults, the rupture rips along … Read entire article »

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Desperate Measure Yields Insights for Delta Restoration

In late spring 2011, one of the largest pulses of water in recorded history traveled down the Mississippi River, threatening the ports, industries, farms and towns of the river’s lower reaches, including New Orleans. To avert disaster, the U.S. Army Corps of Engineers opened the Bonnet Carré Spillway and diverted from 10 to 20 percent of the total river flood discharge into Lake Ponchartrain. Jeffrey Nittrouer, a National Science Foundation post-doctoral researcher at the University of Illinois, studied the impacts of the diversion shortly after the floodwaters subsided. Surprisingly, he found that 31-46% of the total sand load carried by the river during the 6 weeks the spillway was open was carried through the spillway. The location of the spillway was not intentionally chosen for delta restoration. But Nittrouer determined its land building power came from the … Read entire article »

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Field Update: Drilling Through the Japan Earthquake Fault

After successfully reentering the wellhead on the edge of the Japan Trench on the seafloor 6926 meters (4.3 miles) below the ship, we began drilling. The goal: to drill ~850 meters (2800 feet) below the seafloor across the plate boundary and through the fault that slipped more than 50 meters (164 feet) at this location during the March 2011 Tohoku earthquake causing the enormous tsunami. We will then try installing a temperature observatory down into the hole to measure the remaining frictional heat across the fault. Instead of using the standard top-drive drilling system on the ship to rotate the entire drill stem and create the torque on the drill bit 7-8 kilometers below, as in the previous drilling at the site, this time we used a mud-motor located just above … Read entire article »

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Slumbering Greek Volcano Stirs

Over the past year, Greeks have become accustomed to the feeling of the Earth shifting beneath their feet. Now, it’s not just the economy that’s making them uneasy. Measurements from GPS instruments indicate the ground near the mouth of the island volcano Santorini has deformed by about 2.5 inches since January 2011. In that time, the magma chamber has been growing. The island is what remains of one of the largest volcanic eruptions in recorded history 3,600 years ago. It destroyed Minoan settlements and may have inspired the legend of the lost city of Atlantis. According to a post on LiveScience.com by reporter Stephanie Pappas: If a Santorini eruption did occur, [Andrew] Newman said, it would be nothing like the Minoan eruption of 1650 B.C. that birthed the myth of Atlantis. That eruption … Read entire article »

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Scientists Punch Into Ancient Antarctic Lake

Racing against the oncoming southern winter, Russian scientists announced today they have broken through more than 2 miles of ice to dip into a freshwater lake in eastern Antarctica that had been sealed off from the surface for millions of years. Pressurized water from the lake was allowed to rise up and fill the bore hole before freezing solid. Next year, the scientists plan to return to sample the lake water. They are especially keen to know if microbes are currently living in one of the most extreme environments on Earth. The lake is seen as an analog for a liquid lake or ocean under the icy crust of Jupiter’s moon Europa. In a terrific piece on the much anticipated breakthrough for the New York Times today, David Herszenhorn and James Gorman write that environmentalists are concerned … Read entire article »

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Study: Volcanoes Triggered Little Ice Age

Scientists have debated about what caused the Little Ice Age, an unusually cool period that lasted for several centuries and ended in the late 19th century. Some have suggested it was caused by shiny aerosol particles from volcanoes blocking out a portion of sunlight; others have suggested the sun itself was shining less brightly; or, perhaps a bit of both. Until now, the experts couldn’t even agree on when it started. Estimates of onset have ranged from the 13th to the 16th century. A new study published today in the journal Geophysical Research Letters might settle both questions in one fell swoop. The researchers, led by Gifford Miller, a climate scientist at the University of Colorado, Boulder, say new evidence from northern ice sheets suggests the Little Ice Age was triggered by … Read entire article »

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Charles Darwin’s nemesis reconsidered

In his Laelaps blog, science writer Brian Switek explains how much of what you may have heard or read about Richard Owen, famed “anti-evolutionist” and nemesis of Charles Darwin, is in fact wrong. Switek writes: If we wish to tell the stories of highly-influential scientists like Darwin and Owen, the least we can do is try to accurately comprehend their words and what they meant by them. … Read entire article »

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Top earth science news stories of 2011

As usual, there were lots of great earth science related discoveries, events and debates this past year. There were some pretty big items from the Jackson School of Geosciences at UT Austin, but we’ve covered those extensively on the school’s website. So here are a few highlights from beyond our walls that caught our attention: Natural Disasters At number 9 on Discover magazine’s top 100 stories of 2011, we find natural disasters. These include Hurricane Irene in the U.S., flooding in Australia, the earthquake and tsunami that spawned a nuclear catastrophe in Japan, and a devastating drought in East Africa. While we’re at it, Discover posted 5 lessons from the Japanese earthquake. By the way, the second anniversary of the 2010 Haiti earthquake is fast approaching. Jackson School scientists were there soon after to sort out how … Read entire article »

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