[12.571] Anne Bécel (Columbia)

Investigating structural controls on megathrust slip behavior in and around the Guerrero gap off the Pacific Coast of Mexico using active source seismic data

Subduction zone megathrusts display a wide spectrum of fault slip behavior, including rapid slip during large earthquakes, slow slip events and tremors. The Middle America Trench off the West coast of Mexico is an excellent location to study the factors contributing to along strike variability in megathrust slip behavior given that this subduction zone has well-documented regions of rapid slip and slow slip events.  The Guerrero Gap hosts slow slip events (SSEs) propagating to shallow depths while neighboring segments experience rapid seismic slip. In May-June 2022, the ¡Me Gusta! (MexicoExperiment in Guerrero to Understand Shallow Transients near Acapulco) experiment acquired active source seismic data with the R/V Marcus G Langseth within the Guerrero Gap and nearby regions. The multichannel seismic reflection and wide-angle seismic data provide a first-time seismic characterization of offshore subduction zone architecture and properties with ultimate goal of better understanding of linkages between structure and slip behavior. In this talk, I will first present results from seismic imaging and 15-km long streamer tomography across the young incoming Cocos plate and discuss how sediment thickness, top of the oceanic crust roughness and faulting as well as upper oceanic crust pore water estimates vary along-strike. I will then focus on preliminary results from the plate boundary structure and overriding plate properties.

[12.571] Seminar in Geophysics 

Lecture portion of EAPS graduate-level class in geophysics, 12.571. All members of the MIT community are welcome to join for presentations by guest speakers, held approximately every two weeks during the term.  

Contact: erl-info@mit.edu