Collaborative Research: Imaging the Mantle in the Central American Subduction Factory

Brown University, Providence RI

Investigators

Abstract

This award is for an 18 month deployment of 43 PASSCAL broad band seismometers in Nicaragua and Costa Rica to seismically image the mantle "subduction factory" of the Central American volcanic arc in the region. In addition to the PASSCAL instruments, the PIs will also collaborate with Costa Rican and Nicaraguan seismologists to use data from existing short period and broadband instruments. The experiment will image the mantle wedge with receiver functions and other converted waves, together with regional waveform inversions. Tomographic imaging will be used to try to map the region of slab dewatering (and intermediate depth earthquake generation), melt generation and melt migration in the mantle wedge. Patterns of mantle flow will be interpreted from shear wave splitting data, and crustal structure will be inferred from receiver functions. Overall, the idea is to infer the workings of the subduction factory by combining seismic images of the crust and mantle with the modeled interpretations of large observed differences in magma composition along strike in the arc volcanoes.