NSFGEO-NERC: Investigating pre-, co-, and post-eruption processes at Sierra Negra volcano, Galapagos using geodetic and seismic data

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Sierra Negra volcano, in the Galápagos Islands of Ecuador, is one of the largest basaltic calderas on Earth, measuring 9 km by 7 km. Through investments from the NSF RAPID and NERC Urgency programs, the June 26-August 30, 2018 eruption of Sierra Negra was the first eruption at a Galápagos Islands volcano to be recorded by a local geophysical monitoring network. The resulting data are spectacular. The eruption involved >6.5 m of pre-eruptive inflation, formation of a ~12 km long fissure system on the north flank, ~8.5 m of co-eruptive deflation (one of the largest co-eruptive displacements ever observed without collapse on caldera-bounding ring faults), and ~1.5 m of net uplift (resurgence) on the intra-caldera trapdoor fault system. Hundreds of thousands of earthquakes accompanied the pre- and co-eruptive phases, including inflationary and deflationary intra-caldera 'trapdoor' faulting events up to Mw5.4. The NSFGEO-NERC collaborative scheme is ideally suited to bring together unique, complementary geodetic and seismic observations and modeling to address specific questions relating to the behavior of Sierra Negra, the nature of Galápagos volcanism, and important outstanding questions about fundamental volcano deformation and interaction between a volcanic edifice and magma plumbing system.