Central Andean volcano activity changes observed by integrated thermal, photogrammetry, geochemical and InSAR data

Wednesday, 17 December 2014
Thomas R Walter, Jacqueline T. Salzer, Elske De Zeeuw van Dalfsen, Ayleen Gaete Rojas, Nicole Richter, Martin Zimmer, Mehdi Nikkhoo, Christian Kujawa and Stefan Mikulla, GFZ Potsdam, Potsdam, Germany
The volcanoes of the Central Andean Subduction Zone are characterized by mostly explosive eruptions. This makes them especially hazardous and their eruptions have a high potential to affect the aviation safety over extensive areas. Láscar Volcano, in specific, has had explosive eruptions at intervals of 3-5 years within the last decades. Similarly, the volcanoes Lastarria and Putane show signs of activity. To unravel the processes causing the unrest and gain insight into eruption precursors these volcanoes need to be studied in spatial and temporal detail.

Here we present new results on the state of activity of the Central Andean Subduction Zone volcanoes and investigate modes of complex interaction of these volcanoes to their surrounding environment. We generate a very high resolution digital elevation map from terrestrial laser scanner data and combine it with TerraSAR-X satellite data in order to analyse small-scale surface deformation over time. The results allow us to identify localized zones of strain accumulation. Results are compared to the spatial pattern of fumarole sites and their chemical characteristics as recorded by infrared and in situ stations. By means of time lapse camera records, levels of fumarole activity were recorded and compared to the time records of the other data. Integration of all these data into statistical models reveals a complex coupling of volcanic activity to intrinsic and extrinsic processes, including tidal forcing and large tectonic earthquakes. Our results show that the Central Andean Subduction Zone is a prime laboratory location that allows the investigation of how volcanoes and their environment are interacting.