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Marquez-Azua, Bertha
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Marquez-Azua, Bertha
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- PublicationOpen AccessTectonic, volcanic and human activity: ground deformation signals detected by multitemporal InSAR techniques in the Colima Volcanic Complex rift (Mexico(2010-12-15)
; ; ; ; ; ; ; ; ; ; ;Brunori, Carlo Alberto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Bignami, Christian; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Trasatti, Elisa; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Stramondo, Salvatore; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Zucca, Francesco; Università di Pavia - Dip.Scienze della Terra (Pavia, ITALY) ;Groppelli, Gianluca; C.N.R. – Istituto per la Dinamica dei Processi Ambientali, Milano, Italy ;Norini, Gianluca; Università degli Studi di Milano-Bicocca (Milano, ITALY) - Universidad Nacional Autonoma de Mexico, Queretaro, Mexico ;Capra, Lucia; Universidad Nacional Autonoma de Mexico, Queretaro, Mexico ;Cabral-Cano, Enrique; Instituto de Geofìsica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria Del. Coyoacan ;Marquez-Azua, Bertha; Instituto de Geofìsica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria Del. Coyoacan; ; ; ; ; ; ; ; ; ; ; ;Ward, Joanna; American Geofisical Union (S.Francisco-CA USA)The evolution of volcanoes is strictly related with their substratum and the regional tectonics. The link among morphology, geology and structure of volcanic edifices and the geologicalstructural characteristics of the basement is important to understand hazardous phenomena as flank eruptions and lateral collapses of volcanoes. The Colima Rift is an active regional structure, N-S oriented and more than 100 km long and 10 wide. This rift is filled by a ~1 km-thick sequence of quaternary lacustrine sediments, alluvium, and colluvium, mostly underling the about 3000 m thick volcanic pile of the Colima Volcanic Complex (CVC). In addition to the regional structures curved faults, roughly E-W oriented, are observed on the CVC edifice due to the spreading of the volcano moving southward on the weak basement. So in the CVC edifice and surrounding area we can observe the interaction of regional structures and volcanic ones due to the gravitational loading of the volcanic edifice on the weak substratum of the graben. To measure displacements due to magma movement at depth and interaction of regional structures and volcanic ones, SAR interferometry has proven to be a reliable method; however, andesitic stratovolcanoes like the CVC indeed,remain difficult to survey using this technique. The main causes are their specific geometry (steep topography), which induces strong tropospheric artefacts, environmental conditions (e.g.,mainly vegetation, ash and/or snow cover), leading to a loss of coherency. In this work we try to detect deformations phenomena for the wide CVC using a robust multitemporal InSAR approach Differential Synthetic Aperture Radar Interferometry (DInSAR). We apply the Hooper (2008) DInSAR algorithm (StamPS/MTI) both to ENVISAT ASARr images acquired from 1993 to 2007 and to ALOS PALSAR (datasets from 2006 to 2010) in order to determine the deformation patterns in the CVC.350 819 - PublicationRestrictedMagma emission rates fromshallow submarine eruptions using airborne thermal imaging(2014-09)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Hernández, P. A. ;Calvari, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ramos, A. ;Pérez, N. M. ;Márquez, A. ;Quevedo, R. ;Barrancos, J. ;Padrón, E. ;Padilla, G. D. ;López, D. ;Rodríguez Santana, A. ;Melián, G. V. ;Dionis, S. ;Rodríguez, F. ;Calvo, D. ;Spampinato, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;; ; ; ; ; ; ; ; ; ; ; ; ; ;The effusion rate is the most important parameter to gatherwhen a volcanic eruption occurs, because it controls the way inwhich a lava body grows, extends and expands, influencing its dimensional properties. Calculation of lava flow volume from thermal images collected by helicopter surveys has been largely used during the last decade for monitoring subaerial effusive eruptions. However, due to the depths where volcanic activity occurs, monitoring submarine volcanic eruptions is a very difficult task. The 2011–2012 submarine volcanic eruption at El Hierro, Canary Islands, has provided a unique and excellent opportunity to monitor eruptive processes occurring on the seabed. The use of a hand-held thermal camera during daily helicopter flights allowed us to estimate for the first time the daily and total erupted magma volumes from a submarine eruption. The volume of magma emitted during this eruption has been estimated at 300 Mm3, giving an average effusion rate of ~25 m3 s−1. Thermal imagery by helicopter proved to be a fast, inexpensive, safe and reliable technique of monitoring volcanic eruptions when they occur on the shallow seabed.428 47