A Seismogeodetic Amphibious Network in the Guerrero Seismic Gap, Mexico
Por:
Cruz-Atienza V.M., Ito Y., Kostoglodov V., Hjörleifsdóttir V., Iglesias A., Tago J., Calò M., Real J., Husker A., Ide S., Nishimura T., Shinohara M., Mortera-Gutierrez C., García S., Kido M.
Publicada:
1 jul 2018
Categoría:
Geophysics
Resumen:
The historical record of large subduction earthquakes in Guerrero,
Mexico, reveals the existence of an similar to 230-km length segment
below the coast where no major rupture has occurred in the past 60
years. Reliable quantification of the hazard associated with such a
seismic gap is urgently needed for risk mitigation purposes by means of
state-of-the-art observations and modeling. In this article, we
introduce and quantitatively assess the first seismogeodetic amphibious
network deployed in Mexican and Central American soils that will provide
the opportunity to achieve this goal in the near future. Deployed in
2017, the network is the result of a collaborative effort between
Mexican and Japanese scientists. It consists of 15 onshore broadband and
7 ocean-bottom seismometers, 33 Global Positioning System (GPS)
stations, 7 ocean-bottom pressure gauges, and 2 GPS-acoustic sites, most
of them installed within the Guerrero seismic gap. Initial data from the
network revealed the occurrence of a 6-month-long slow-slip event in
Guerrero, starting in May and ending in October 2017. To illustrate the
performance of the various instruments, we also present the first
ocean-bottom pressure and GPS-acoustic measurements in Mexico; the
latter was obtained by means of an autonomous Wave Glider vehicle. The
ground motion of the devastating 19 September 2017 M-w 7.1 earthquake in
central Mexico is presented as well. Nominal resolution of the
seismogeodetic network is estimated through different synthetic
inversion tests for tomographic imaging and the seismic coupling (or
slow-slip) determination on the plate interface. The tests show that
combined onshore and offshore instruments should lead to unprecedented
results regarding the seismic potential (i.e., interface coupling) of
the seismic gap and the Earth structure from the Middle America trench
up to 70-km depth across the Guerrero state.
Filiaciones:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan
Facultad de Ingeniería, Universidad Nacional Autónoma de México, Mexico City, Mexico
Department of Earth and Planetary Physics, University of Tokyo, Tokyo, Japan
Earthquake Research Institute, University of Tokyo, Tokyo, Japan
Research Center for Prediction of Earthquakes and Volcanic Eruptions, Tohoku University, Sendai, Japan
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