Seafloor Geodetic Investigation of Shallow Slow Slip Events at the Hikurangi Subduction Margin, New Zealand
Wednesday, 24 February 2016: 4:35 PM
Laura M Wallace, University of Texas at Austin, Institute for Geophysics, Austin, TX, United States, Spahr C Webb, Lamont Doherty Earth Observ, Palisades, NY, United States, Yoshihiro Ito, Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan, Kimihiro Mochizuki, Earthquake Research Institute, University of Tokyo, Tokyo, Japan, Ryota Hino, Tohoku University, Sendai, Japan, Stuart A Henrys, GNS Science-Institute of Geological and Nuclear Sciences Ltd, Lower Hutt, New Zealand, Susan Y Schwartz, University of California-Santa Cruz, Santa Cruz, CA, United States and Anne F Sheehan, University of Colorado at Boulder, Boulder, CO, United States
Abstract:
Shallow slow slip events (<10-15 km depth) are well-documented at the northern Hikurangi subduction margin, New Zealand. As part of the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) project, we deployed and successfully recovered a dense network (<10 km spacing) of 24 Absolute Pressure Gauges (APG) and 15 Ocean Bottom Seismometers (OBS) to investigate vertical seafloor deformation and seismicity related to shallow slow slip. The HOBITSS network was deployed for one year from May 2014 to June 2015, in a region directly above an area of large, shallow slow slip events offshore Gisborne, New Zealand. A large slow slip event occurred directly beneath the HOBITSS network in September/October of 2014. We will present an overview of results on seafloor deformation seen in the APG data from the September/October SSE. The HOBITSS experiment APG results have allowed us to examine the trenchward extent and detailed distribution of shallow SSE deformation for the first time. This project represents the first-ever, large-scale seafloor geodetic investigation targeted at the study of offshore slow slip events.
