* Astronomy

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Fragmented Structure of Seafloor Faults May Dampen Effects of Earthquakes
Studies of gravity fields suggest volcanism may smooth rough edges of tectonic plates

Many earthquakes in the deep ocean are much smaller in magnitude than expected. Geophysicists from the Woods Hole Oceanographic Institution (WHOI) have found new evidence that the fragmented structure of seafloor faults, along with previously unrecognised volcanic activity, may be dampening the effects of these quakes.
Examining data from 19 locations in the Atlantic, Pacific, and Indian oceans, researchers led by graduate student Patricia Gregg have found that transform faults are not developing or behaving as theories of plate tectonics say they should. Rather than stretching as long, continuous fault lines across the seafloor, the faults are often segmented and show signs of recent or ongoing volcanism. Both phenomena appear to prevent earthquakes from spreading across the seafloor, thus reducing their magnitude and impact.
Gregg, a doctoral candidate in the MIT/WHOI Joint Program in Oceanography and Oceanographic Engineering, conducted the study with seismologist Jian Lin and geophysicists Mark Behn and Laurent Montesi, all from the WHOI Department of Geology and Geophysics. Their findings were published in the July 12 issue of the journal Nature.

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New data shake quake strategy
Analysis of foreign disasters may allow state to ease strict building codes.
Like aftershocks that just keep rumbling, big earthquakes from Taiwan to Turkey could leave a lasting mark on California.
Evidence from those distant quakes has bolstered a growing conviction that California won't shake as violently as once feared when the next big one hits.
Implications could be widespread, from relief for hospitals now struggling with how to pay for earthquake retrofits to cities figuring which overpasses they can afford to upgrade.

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The violent rumblings of a major earthquake can almost immediately intensify nearby volcanic eruptions, scientists said today.
Three days after a 6.4-magnitude earthquake shook Indonesias Java Island in May 2006, killing nearly 6,000 people, the intensity of two of the islands ongoing volcanic eruptions increased sharply. The heightened activity lasted for about nine days.

During this period, we found clear evidence that the earthquake caused both volcanoes to release greater amounts of heat, and lava emission surged to two to three times higher than prior to the tremor -  Andrew Harris, study lead author, University of Hawaii.

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