Tag Archives: volcanoes

California Faults Moved Quietly After Baja Quake

A new NASA study finds that a major 2010 earthquake in northern Mexico triggered quiet, non-shaking motions on several Southern California faults that released as much energy as a magnitude 4.9 to 5.3 earthquake.

The quiet motion associated with the widely felt, magnitude 7.2 earthquake centered in northern Baja California in Mexico, in April 2010 was discovered in before-and-after radar images of the region made by a NASA airborne instrument that produces extremely accurate maps of Earth motions. The Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), which flies on a NASA C-20A aircraft from NASA’s Armstrong Flight Research Center facility in Palmdale, Calif., allows scientists to see how locations on Earth’s surface change between repeat flights over the same spot. (more…)

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New study reveals insights on plate tectonics, the forces behind earthquakes, volcanoes

The Earth’s outer layer is made up of a series of moving, interacting plates whose motion at the surface generates earthquakes, creates volcanoes and builds mountains. Geoscientists have long sought to understand the plates’ fundamental properties and the mechanisms that cause them to move and drift, and the questions have become the subjects of lively debate.

A study published online Feb. 27 by the journal Science is a significant step toward answering those questions. (more…)

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Some volcanoes ‘scream’ at ever-higher pitches until they blow their tops

It is not unusual for swarms of small earthquakes to precede a volcanic eruption. They can reach a point of such rapid succession that they create a signal called harmonic tremor that resembles sound made by various types of musical instruments, though at frequencies much lower than humans can hear.

A new analysis of an eruption sequence at Alaska’s Redoubt Volcano in March 2009 shows that the harmonic tremor glided to substantially higher frequencies and then stopped abruptly just before six of the eruptions, five of them coming in succession. (more…)

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Scientists Cast Doubt on Theory of What Triggered Antarctic Glaciation

AUSTIN, Texas — A team of U.S. and U.K. scientists has found geologic evidence that casts doubt on one of the conventional explanations for how Antarctica’s ice sheet began forming. Ian Dalziel, research professor at The University of Texas at Austin’s Institute for Geophysics and professor in the Jackson School of Geosciences, and his colleagues report the findings today in an online edition of the journal Geology.

The Antarctic Circumpolar Current (ACC), an ocean current flowing clockwise around the entire continent, insulates Antarctica from warmer ocean water to the north, helping maintain the ice sheet. For several decades, scientists have surmised that the onset of a complete ACC played a critical role in the initial glaciation of the continent about 34 million years ago. (more…)

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NASA’s HyspIRI Sees the Forest for the Trees and More

To Robert Green, light contains more than meets the eye: it contains fingerprints of materials that can be detected by sensors that capture the unique set of reflected wavelengths. Scientists have used the technique, called imaging spectroscopy, to learn about water on the moon, minerals on Mars and the composition of exoplanets. Green’s favorite place to apply the technique, however, is right here on the chemically rich Earth, which is just what he and colleagues achieved this spring during NASA’s Hyperspectral Infrared Imager (HyspIRI) airborne campaign.

“We have ideas about what makes up Earth’s ecosystems and how they function,” said Green, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who is principal investigator of the campaign’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument. “But a comprehensive understanding requires us to directly measure these things and how they change over landscapes and from season to season.” (more…)

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NASA Radar Penetrates Thick, Thin of Gulf Oil Spill

PASADENA, Calif. – Researchers at NASA’s Jet Propulsion Laboratory and the California Institute of Technology in Pasadena have developed a method to use a specialized NASA 3-D imaging radar to characterize the oil in oil spills, such as the 2010 BP Deepwater Horizon spill in the Gulf of Mexico. The research can be used to improve response operations during future marine oil spills.

Caltech graduate student Brent Minchew and JPL researchers Cathleen Jones and Ben Holt analyzed NASA radar imagery collected over the main slick of the BP Deepwater Horizon oil spill on June 22 and June 23, 2010. The data were acquired by the JPL-developed Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) during the first of its three deployments over the spill area between June 2010 and July 2012. The UAVSAR was carried in a pod mounted beneath a NASA C-20A piloted aircraft, a version of the Gulfstream III business jet, based at NASA’s Dryden Aircraft Operations Facility in Palmdale, Calif. The researchers demonstrated, for the first time, that a radar system like UAVSAR can be used to characterize the oil within a slick, distinguishing very thin films like oil sheen from more damaging thick oil emulsions. (more…)

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CU-Boulder-led Team Finds Microbes in Extreme Environment on South American Volcanoes

A team led by the University of Colorado Boulder looking for organisms that eke out a living in some of the most inhospitable soils on Earth has found a hardy few.

A new DNA analysis of rocky soils in the Martian-like landscape on some volcanoes in South America has revealed a handful of bacteria, fungi and other rudimentary organisms called archaea, which seem to have a different way of converting energy than their cousins elsewhere in the world.

“We haven’t formally identified or characterized the species,” said Ryan Lynch, a CU-Boulder doctoral student involved in the study. “But these are very different than anything else that has been cultured. Genetically, they’re at least 5 percent different than anything else in the DNA database of 2.5 million sequences.” (more…)

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Mapping Volcanic Heat on Io

A new study finds that the pattern of heat coming from volcanoes on Io’s surface disposes of the generally-accepted model of internal heating. The heat pouring out of Io’s hundreds of erupting volcanoes indicates a complex, multi-layer source. These results come from data collected by NASA spacecraft and ground-based telescopes and appear in the June issue of the journal Icarus.

A map of hot spots, classified by the amount of heat being emitted, shows the global distribution and wide range of volcanic activity on Io. Most of Io’s eruptions dwarf their contemporaries on Earth. (more…)

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