Volcanic hotspots of the central and southern Andes as seen from space by ASTER and MODVOLC between the years 2000 and 2010
Published:January 01, 2013
J. A. Jay, M. Welch, M. E. Pritchard, P. J. Mares, M. E. Mnich, A. K. Melkonian, F. Aguilera, J. A. Naranjo, M. Sunagua, J. Clavero, 2013. "Volcanic hotspots of the central and southern Andes as seen from space by ASTER and MODVOLC between the years 2000 and 2010", Remote Sensing of Volcanoes and Volcanic Processes: Integrating Observation and Modelling, D. M. Pyle, T. A. Mather, J. Biggs
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We examine 150 volcanoes and geothermal areas in the central, southern and austral Andes for thermal anomalies between the years 2000 and 2010 from two different spaceborne sensors: (1) those automatically detected by the MODVOLC algorithm from MODIS; and (2) manually identified hotspots in night-time images from ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer). Based on previous work, we expected to find eight volcanoes displaying thermal anomalies (Ubinas, Villarrica, Copahue, Láscar, Llaima, Chaitén, Lonquimay and Chiliques). We document 35 volcanic areas with pixel-integrated temperatures of 4 up to more than 100 K above background in at least two images, and another 16 areas that have questionable hotspots with either smaller anomalies or a hotspot identified in only one image. Most of the thermal anomalies are related to known activity (i.e. lava and pyroclastic flows, growing lava domes, fumaroles, and lakes) while others are of unknown origin or reflect activity at volcanoes that were not thought to have surface activity. A handful of volcanoes exhibit temporal variations in the magnitude and location of their temperature anomalies that can be related to both documented and undocumented pulses of activity. Our survey reveals that low-amplitude volcanic hotspots detectable from space are more common than expected, based on lower spatial resolution data, and that these features could be more widely used to monitor changes in the activity of remote volcanoes. We find no evidence from ASTER or MODVOLC that the thermal anomalies were affected by six earthquakes with Mw above 7 in our study area from 2000 to 2010, although the observations may not have been optimal to detect such anomalies.
Supplementary material: Supplementary tables of data and figures for the volcanoes studied are available at http://www.geolsoc.org.uk/SUP18581.
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Remote Sensing of Volcanoes and Volcanic Processes: Integrating Observation and Modelling
Volcanoes have played a profound role in shaping our planet, and volcanic activity is a major hazard locally, regionally and globally. Many volcanoes are, however, poorly accessible and sparsely monitored. Consequently, remote sensing is playing an increasingly important role in tracking volcano behaviour, while synoptic remote sensing techniques have begun to make major contributions to volcanological science. Volcanology is driven in part by the operational concerns of volcano monitoring and hazard management, but the goal of volcanological science is to understand the processes that underlie volcanic activity. This volume shows how we may reach a deeper understanding by integrating remote sensing measurements with modelling approaches and, if available, ground-based observations. It includes reviews and papers that report technical advances and document key case studies. They span a range of remote sensing applications to volcanoes, from volcano deformation, thermal anomalies and gas fluxes, to the tracking of eruptive ash and gas plumes. The result is a state-of-the-art overview of the ever-growing importance of remote sensing to volcanology.