SEMINAR: Fwd: GEOTOPICS TODAY-- "Disaster triggers disaster: Earthquake triggering by wet tropical cyclones"

[orash sharifi <osharifi@rsmas.miami.edu>]

Monday, October 31, 2011
3:15, SLAB Seminar Room, S/A 103
Refreshments at 3:00 PM

Our upcoming speaker is one of our own top scientists  at MGG: Shimon Wdowinski 

The title of his talk is "Disaster Triggers Disaster: Earthquake Triggering by Wet Tropical Cyclones".

ABSTRACT

  Three recent devastating earthquakes, the 1999 M = 7.6 Chi-Chi (Taiwan), 2010 M=7.0 Haiti, 2010 M=6.4 Kaohsiung (Taiwan), and three moderate size earthquakes (6<M<7) occurred in tropical mountainous areas shortly after very wet tropical cyclones (hurricane or typhoon) hit the same area. We suggest that the close proximity in time and space between wet cyclones and M>6 earthquakes reflects a physical link between the two hazard types in which these earthquakes were triggered by rapid erosion induced by tropical cyclone’s heavy rain. Based on mesh-free finite element modeling and Coulomb failure stress analysis, we show that erosion induced by very wet cyclones increased the failure stresses at the hypocenters’ depth by 300-1200 Pa, which ultimately triggered these earthquakes. Our results suggest that the observed three-fold frequency increase of M>6 earthquakes in Taiwan’s mountainous area over the past 15 years, directly correlates with and is caused by increased wet cyclone frequency. Statistical analysis of the earthquake and cyclone datasets indicates a very low probability (1-5%) for the occurrence of the observed typhoon-earthquake distribution by a random earthquake occurrence process.

We hope to see you all there!

Your GEOTOPICS Coordinators,
Keri Vinas and Arash Sharifi
        

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