Complex rupture of the M 6.3 2015 March 10 Bucaramanga earthquake: evidence of strong weakening process

TitleComplex rupture of the M 6.3 2015 March 10 Bucaramanga earthquake: evidence of strong weakening process
Publication TypeJournal Article
Year of Publication2016
AuthorsPoli, P, Prieto, G, Yu, C, Florez, M, Agurto-Detzel, H, Mikesell, TD, Gu, C, Dionicio, V, Pedraza, P
JournalGeophysical Journal International
Volume205
Issue2
Pagination988 - 994
Date PublishedJan-05-2016
ISSN0956-540X
KeywordsBody waves, Earthquake dynamics, Earthquake source observations
Abstract

We use seismic waves for a magnitude 6.3 intermediate-depth (160 km) earthquake in the Bucaramanga Nest, Colombia, to infer a complex rupture process with two distinct stages, characterized by different rupture velocities possibly controlled by the evolution of strength on the fault. Our integrated data processing permitted to precisely characterize the multistage rupture and the presence of a strong weakening event. The resulting seismic radiation is interpreted as resulting from an extreme weakening due to a cascading thermal shear runaway, with an initial inefficient radiation process followed by a fast and dynamic efficient rupture. Our results imply dynamic complexity of the seismic rupture deep inside the Earth, and may help to give some new insights about the physical mechanism of intermediate-depth earthquakes.

URLhttp://gji.oxfordjournals.org/lookup/doi/10.1093/gji/ggw065
DOI10.1093/gji/ggw065
Short TitleGeophys. J. Int.