Fingerprinting Slow Earthquakes

CarnegieScience writes "The most powerful earthquakes happen at the junction of two converging tectonic plates, where one plate is sliding (or subducting) beneath the other. Now a team of researchers, led by Teh-Ru Alex Song of the Carnegie Institution's Department of Terrestrial Magnetism, has found that an anomalous layer at the top of a subducting plate coincides with the locations of slow earthquakes and non-volcanic tremors. The presence of such a layer in similar settings elsewhere could point to other regions of slow quakes."

Comments

Paging all geologists

[orclevegam]

Can someone explain WTF a "slow earthquake" is, and why we care? From reading the article it sounds like it has something to do with the speed the compression wave propagates through the crust at, but why that matters I'm not quite sure. No matter what the propagation speed is it's still going to tear things up when it finally does get to you.