Detall
(Gene Humphreys) Dangling slabs beneath the western United States and the deep April 11th, 2010 Granada earthquake
SEMINARIS DE LA FACULTAT DE GEOLOGIA I L'INSTITUT DE CIÈNCIES DE LA TERRA 'JAUME ALMERA'
The accretion of ocean lithosphere to NW USA ~50 Ma caused the Laramide orogeny to end and, as the flat-subducting slab fell away from the continent, it started a large volcanic event that swept across much of the western USA. It also left a large piece of this lithosphere dangling across the entire upper mantle. I will present this story and follow it with our analysis of the 11/4/10, 650 km deep earthquake beneath Granada. We conclude that this earthquake consisted of two main sub-events that occurred within 3 seconds: the first sub-event was a slip-pulse earthquake dropping 1-2 MPa; the second was a crack-like earthquake dropping 100s of MPa. Clearly, two different rupture mechanisms were involved.
Dia: 3 de Novembre de 2011
Hora: 12h
Lloc: Sala d'actes de l'Institut Jaume Almera