Details

• Dr. Fabien Albino, Dept. Earth Sciences, Cartography & Remote Sensing Unit, Royal Museum for Central Africa, Belgium
• Date: December, 10, 2014 12:00 am
• Place: Sala d’Actes del Institut de Ciències de la Terra Jaume Almera(ICTJA)
• Location: C/ Solé i Sabarís s/n, Barcelona

Abstract

Since 2007, I used physical numerical modelling and SAR interferometry to better understand the behaviour of magmatic system. I will show you several works I’ve realized during past research projects. In many effusive eruptions, the magma is initiated from a shallow reservoir located below the edifice. It is well known that the main triggering of such eruption is the pressurization of the reservoir due to magma re-alimentation or crystallization. At a certain threshold, the pressure will cause the failure of the reservoir and the propagation of the magma towards the surface. However, small stress changes in the crust around the volcanic system, such as earthquakes, icecap melting or edifice growth, may affect these failure conditions. From mechanical models, we quantify the effect of small stress changes on magma reservoirs, with the example of icelandic subglacial volcanoes (Eyjafjallajökull, Katla and Grimsvötn). Once the magma propagates and arrives in surface, lava flows in the volcanic area. Radar interferometry can detect pre- and co-eruptive ground deformation and provide some constraints on the magmatic system. Moreover, recent sensors, such as TanDEM-X, can add information thanks to the bi-static mode. Bi-static interferometry is useful to create temporal series of Digital Elevation Model to evaluate with accuracy the lava thicknesses, the total erupted volume and eventually the magma flow rate. We will show the gain of information obtained from TanDEM-X interferometry on Nyamulagira volcano (D.R. of Congo): one of the most active volcanoes in Africa, but also one of the most poorly studied due to continuous civil wars.