Simultaneous ash venting and effusive magma extrusion modulated by fracture outgassing at the 2011-2012 Cordón Caulle eruption, Chile

TRAMONTANO, S. ; FORTE, P.; CROZIER, J.A.; OLIVA, S.J.C.; AMIGO, A.; CASTRO, J.M.; GONNERMANN, H.; HOUGHTON, B. F.; LEV, A.; MANGA, M.; MYERS, M.; PAISLEY, R.; RADER, E.; RUPRECHT, P.; SCHIPPER, C.I.; SHEA, T.; TUFFEN, H.

San Francisco

Congreso; American Geophysical Union, Fall Meeting 2019; 2019

American Geophysical Union

The processes that produce and sustain months of persistent effusive lava dome and/or flow eruptions with simultaneous ash venting are not well understood. Deciphering and quantifying these processes is crucial for improved monitoring of eruptions, interpreting historic eruptive deposits, and understanding effusive outgassing mechanisms that play a major role in controlling eruption explosivity. Recent eruptions at Chaitén (2008-2009) and Cordón Caulle (2011-2012) have provided us with the first direct observations of simultaneous ash venting and effusive extrusion of rhyolitic lava. Among historic silicic eruptions, these eruptions are uniquely similar in their fast effusive rate (40-65 m3/s), low phenocryst content (