Mostrar el registro sencillo del ítem Gonzales, Katherine Finizola, Anthony Lénat, Jean-François Macedo Sánchez, Orlando Efraín Ramos Palomino, Domingo A. Thouret, Jean-Claude Fournier, Michel Cruz, Vicentina Pistre, Karine
dc.coverage.spatial Ubinas, Volcán (Moquegua, Perú) 2018-09-11T19:54:08Z 2018-09-11T19:54:08Z 2014-04
dc.identifier.citation Gonzales, K., Finizola, A., Lénat, J. F., Macedo, O., Ramos, D., Thouret, J. C., ... Pistre, K. (2014). Asymmetrical structure, hydrothermal system and edifice stability: The case of Ubinas volcano, Peru, revealed by geophysical surveys.==$Journal of Volcanology and Geothermal Research, 276,$==132-144. es_ES
dc.identifier.govdoc index-oti2018
dc.description.abstract Ubinas volcano, the historically most active volcano in Peru straddles a low-relief high plateau and the flank of a steep valley. A multidisciplinary geophysical study has been performed to investigate the internal structure and the fluids flow within the edifice. We conducted 10 self-potential (SP) radial (from summit to base) profiles, 15 audio magnetotelluric (AMT) soundings on the west flank and a detailed survey of SP and soil temperature measurements on the summit caldera floor. The typical “V” shape of the SP radial profiles has been interpreted as the result of a hydrothermal zone superimposed on a hydrogeological zone in the upper parts of the edifice, and depicts a sub-circular SP positive anomaly, about 6 km in diameter. The latter is centred on the summit, and is characterised by a larger extension on the western flank located on the low-relief high plateau. The AMT resistivity model shows the presence of a conductive body beneath the summit at a depth comparable to that of the bottom of the inner south crater in the present-day caldera, where intense hydrothermal manifestations occur. The lack of SP and temperature anomalies on the present caldera floor suggests a self-sealed hydrothermal system, where the inner south crater acts as a pressure release valve. Although no resistivity data exists on the eastern flank, we presume, based on the asymmetry of the basement topography, and the amplitude of SP anomalies on the east flank, which are approximately five fold that on the west flank, that gravitational flow of hydrothermal fluids may occur towards the deep valley of Ubinas. This hypothesis, supported by the presence of hot springs and faults on the eastern foot of the edifice, reinforces the idea that a large part of the southeast flank of the Ubinas volcano may be altered by hydrothermal activity and will tend to be less stable. One of the major findings that stems from this study is that the slope of the basement on which a volcano has grown plays a major role in the geometry of the hydrothermal systems. Another case of asymmetrical composite cone edifice, built on a steep topography, is observed on El Misti volcano (situated 70 km west of Ubinas), which exhibits a similar SP pattern. These types of edifices have a high potential of spreading and sliding along the slope owing to the thicker accumulation of low cohesion and hydrothermally altered volcanic products. es_ES
dc.format application/pdf es_ES
dc.language.iso eng es_ES
dc.publisher Elsevier es_ES
dc.relation.ispartof urn:issn:0377-0273
dc.rights info:eu-repo/semantics/closedAccess es_ES
dc.subject Ubinas volcano es_ES
dc.subject Hydrothermal system es_ES
dc.subject Self-potential es_ES
dc.subject Audio-magnetotelluric soundings es_ES
dc.subject Soil temperature es_ES
dc.subject Edifice stability es_ES
dc.title Asymmetrical structure, hydrothermal system and edifice stability: The case of Ubinas volcano, Peru, revealed by geophysical surveys es_ES
dc.type info:eu-repo/semantics/article es_ES
dc.subject.ocde es_ES
dc.subject.ocde es_ES
dc.subject.ocde es_ES
dc.subject.ocde es_ES
dc.identifier.journal Journal of Volcanology and Geothermal Research es_ES
dc.description.peer-review Por pares es_ES
dc.identifier.doi es_ES




Mostrar el registro sencillo del ítem