[12.571 / ESS] Earth Science Seminar – Andrew Bell (University of Edinburgh)

“Seismological contributions to understanding volcano dynamics in the western Galápagos islands”

The volcanoes of the western Galápagos Islands, Ecuador, are amongst the most dynamic on Earth. The six active basaltic calderas are almost always deforming. Recent eruptions have been preceded by metres of surface uplift and accompanied by metres of subsidence as magma accumulates in, and then withdraws from, shallow storage. The volcanoes share broad morphological and behavioural features, but each has a set of unique physical characteristics. Consequently, they offer an exceptional natural laboratory to study the nature of interactions between the magmatic system and the edifice, and the behaviour of volcanic crust and fault systems under unusual and extreme stressing conditions.

Local deployments of seismic instruments at Sierra Negra (2018-) and Fernandina (2022-) are providing exciting new datasets, elucidating the details of these remote systems for the first time. In this talk I will describe how seismology has contributed to our understanding of the mechanisms of magma storage, migration, and eruption at Sierra Negra and Fernandina volcanoes. I will discuss the details of seismicity before, during, and after recent eruptions, the role of intra-caldera faulting in accommodating magma accumulation, and the seismic response of volcano flanks to magma intrusion. I’ll reflect on the challenges (and privileges) of building and maintaining a seismic monitoring network in the Galápagos, and share the latest results following this summer’s fieldwork.

Earth Science Seminar:

Lecture portion of the EAPS graduate-level class 12.571, covering current research in geophysics, geology, geochemistry, and geobiology. 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