Published on August 29th, 2012 | by Steven Hodson0
Researchers Discover Earthquake Trigger Points – Call Them “Melt Welts”
Earthquakes cause untold human and financial disaster when they strike so it is no wonder that scientists have been trying to find some way to predict when and where earthquakes will occur, and scientists at Scripps Institution of Oceanography at UC San Diego believe they may have found those trigger points.
In a paper published in the august 30 issue of Nature Scripps scientists Kevin Brown and Yuri Fialko outline new information that they have managed to glean from laboratory experiments that mimic earthquakes. One of the things that they found is how fault zones weaken in select locations shortly after a fault reaches an earthquake tipping point.
That point is, as they have coined the term, called “melt welts” and the analogy used is that the mechanism may be similar to “hot spots” as found in automobile break-clutch components.
“Melt welts appear to be working as part of a complicated feedback mechanism where complex dynamic weakening processes become further concentrated into initially highly stressed regions of a fault,” said Brown, first author of the study and a professor in the Geosciences Research Division at Scripps. “The process allows highly stressed areas to rapidly break down, acting like the weakest links in the chain. Even initially stable regions of a fault can experience runaway slip by this process if they are pushed at velocities above a key tipping point.”
“This adds to the fundamental understanding of the earthquake process because it really addresses the question of how these ruptures become energetic and dynamic and run away for long distances,” said Fialko, a paper coauthor and a professor in the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics at Scripps.
via eScience News
While being able to detect these “melt welts” won’t necessarily lead to early earthquake detection it will allow for improved “shake” maps of ground-shaking intensities as well as improvements in structural engineering plans.