000007393 001__ 7393
000007393 005__ 20250122113220.0
000007393 037__ $$aPOSTER-2025-0030
000007393 100__ $$aTorres-Orozco, Rafael
000007393 245__ $$aCombined pyroclast microtextures and seismic noise records demonstrate shallow andesite magma decompression drives different PDC mechanisms at Volcán de Colima, Mexico
000007393 260__ $$c2023
000007393 269__ $$c2023-12-11
000007393 520__ $$aVolcán de Colima, the most active andesitic stratovolcano in Mexico, last erupted explosively on July 10-11, 2015, producing pyroclastic density currents (PDCs) of different type. The July-10 PDCs formed dense block-and-ash flow deposits typical of Volcán de Colima's history of recurrent summit dome effusion and collapse. In contrast, the July-11 PDCs comprised hot and turbulent scoria-rich PDCs that were unforeseen, and whose triggers and precursors were unidentified. Here, chemical and microtextural analyses of the July-11 deposits via electron-microscopy and x-rays microtomography revealed that decompression of andesite magma at fluctuating rates (10-3-100 MPa s-1) from 2 km-depth triggered magma degassing and crystallization. The resulting extremely rheologically heterogeneous magma fragmented and powered the pulsating July-11 PDCs that released 100-300 m3 s-1 on surface. Seismic noise velocity variations identified in each day down to 2 km-depth support magma decompression from a shallow reservoir. The combined geological and seismological evidence suggest timescales of only hours to couple of days from conduit and dome cracking and collapse to magma decompression and eruption.
000007393 594__ $$aNO
000007393 6531_ $$aVolcanology
000007393 6531_ $$aEruption
000007393 700__ $$aDe Plaen, Raphael
000007393 700__ $$aCapra, Lucia
000007393 700__ $$aMarquez, Victor H.
000007393 700__ $$aSulpizio, Roberto
000007393 700__ $$aArambula, Raúl
000007393 773__ $$tAGU Fall Meeting, San Francisco
000007393 8560_ $$fraphael.deplaen@ksb-orb.be
000007393 85642 $$ahttps://ui.adsabs.harvard.edu/abs/2023AGUFM.V13B0111T/abstract
000007393 980__ $$aCPOSTER