Complex rupture of the M6.3 2015 March 10 Bucaramanga earthquake: evidence of strong weakening process. Issue 2 (15th February 2016)

• Record Type: Journal Article
• Authors: Poli, P.; Prieto, G.A.; Yu, C.Q.; Florez, M.; Agurto-Detzel, H.; Mikesell, T.D.; Chen, G.; Dionicio, V.; Pedraza, P.
• Is Part Of: Geophysical journal international. Volume 205:Issue 2(2016:May)
• Page Start: 988
• Page End: 994
• Publication Date: 2016-02-15
• Subjects: Earthquake dynamics -- Earthquake source observations -- Body waves; Geophysics -- Periodicals; 550
• DOI: 10.1093/gji/ggw065
• Languages: English
• ISSNs: 0956-540X

Abstract

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.