15:30 〜 16:30
[J07-P-01] Towards an Ocean Bottom Geodetic Observatory In Mexico: The First Steps
Ocean bottom geodesy has proven important for observing static offsets occurring during large earthquakes (e.g. Sato et al 2011; Ito et al 2011; Kido et al 2011), to observe slow earthquakes (Ito et al 2013; Wallace et al., 2016), as well as slower tectonic motions (Chadwell & Spiess, 2008).
The Guerrero Seismic Gap, a one hundred kilometer segment of the Mexican subduction zone, has not experienced a large earthquake since at least 1911 (Singh et al 1981). Whether the zone is ripe for a new earthquake or not, depends on the amount of aseismic slip occurring on the fault plane in the inter seismic period, either as continuous creep or slow slip events. In the down-dip part of the segment, large (M~7) slow slip events have been observed about every four years (e.g. Kostoglodov 2003, Larson et al 2006, Radiguet et al 2012). However, it is not clear to which degree the near trench area participates in these events. The Guerrero Gap is the closest segment of the subduction zone to Mexico City. A large event in this zone could cause severe damage to Mexico City and could generate a tsunami that could strongly impact Acapulco and neighboring regions.
As a collaboration between SATREPS/JICA in Japan, and UNAM and CONACyT in Mexico, a network of 2 GPS-Acoustic sites as well as 7 ocean bottom pressure recorders is planned offshore the Mexican coast, in the Guerrero Gap. A wave glider will be used to measure the position of the GPS-A sites. The installation of the first instruments is planned for June 2017. This presentation will detail the types of instruments that are planned and their distribution, the type of signals that we hope to collect as well as the plans for the future.
The Guerrero Seismic Gap, a one hundred kilometer segment of the Mexican subduction zone, has not experienced a large earthquake since at least 1911 (Singh et al 1981). Whether the zone is ripe for a new earthquake or not, depends on the amount of aseismic slip occurring on the fault plane in the inter seismic period, either as continuous creep or slow slip events. In the down-dip part of the segment, large (M~7) slow slip events have been observed about every four years (e.g. Kostoglodov 2003, Larson et al 2006, Radiguet et al 2012). However, it is not clear to which degree the near trench area participates in these events. The Guerrero Gap is the closest segment of the subduction zone to Mexico City. A large event in this zone could cause severe damage to Mexico City and could generate a tsunami that could strongly impact Acapulco and neighboring regions.
As a collaboration between SATREPS/JICA in Japan, and UNAM and CONACyT in Mexico, a network of 2 GPS-Acoustic sites as well as 7 ocean bottom pressure recorders is planned offshore the Mexican coast, in the Guerrero Gap. A wave glider will be used to measure the position of the GPS-A sites. The installation of the first instruments is planned for June 2017. This presentation will detail the types of instruments that are planned and their distribution, the type of signals that we hope to collect as well as the plans for the future.