JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Tectonophysics

[S-IT28] [EE] Seismic attenuation: Observations, Experiments, and Interpretations

Sat. May 20, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Yasuko Takei(Earthquake Research Institute, University of Tokyo), Douglas Wiens(Washington University in St Louis), Nozomu Takeuchi(Earthquake Research Institute, University of Tokyo)

[SIT28-P06] Seismic Attenuation Tomography of Gofar Transform Fault, East Pacific Rise Using OBS Observations

*Haijiang Zhang1, Jing Hu1, Hao Guo1 (1.University of Science and Technology of China, School of Earth and Space Sciences)

Keywords:Gofar transform fault, Seismic attenuation tomography, Structure segmentation

Gofar transform fault of East Pacific Rise generates Mw 5.5-6 large earthquakes quasi-periodically on some segments of the fault, which are separated by stationary rupture barriers. Earthquakes in the seismic cycle of the large earthquake have clear spatial and temporal evolutions. To better understand the relationship between the earthquake behavior and the physical properties of the fault zone along the strike, Woods Hole Oceanographic Institution deployed a broadband ocean bottom seismograph (OBS) array on Gofar transform fault for 1-year continuous measurements, which successfully captured a Mw 6.0 earthquake on18 September 2008 and provided an unprecedented dataset. By using t* values determined from fitting seismic waveform frequency spectrum, we have conducted three-dimensional seismic attenuation tomography to determine along-strike attenuation structure. Combined with the high-resolution earthquake locations and Vp, Vs and Vp/Vs models determined from seismic velocity tomography, we found that the seismicity behavior is mainly controlled by structure heterogeneities along the fault.