AN OVERVIEW OF VOLCANOLOGICAL APPLICATIONS OF REMOTE SENSING

This presentation is an overview of applications of remote sensing to a selection of volcanic phenomena and volcanoes. The overview format cannot do justice to the breadth of applications and data sets listed below, so the objective of this presentation is to showcase the utility of remote sensing to volcanological investigations and the ingenuity of remote sensing volcanologists.

Remote sensing has been used to study a wide range of volcanic phenomena, including the emplacement and cooling of lava flows, growth of lava domes, emission of gas from vents and fumaroles, formation and dissipation of eruption clouds, and magma-induced ground deformation. The synoptic perspective and repetitive coverage afforded by remote sensing surveys creates the time series data sets necessary for the detection and recognition of changes in the behavior of a volcano. These data can also be used to assess the impact of volcanic processes on the local environment.

Volcanological investigations utilize most of wavelength range exploited by remote sensing. Sulfur dioxide plumes and clouds are mapped in the ultraviolet (UV) and thermal infrared (TIR), ash and aerosol clouds are mapped in the UV, TIR, and visible and near infrared (VNIR), high temperature thermal features are mapped in the VNIR, low temperature thermal features are mapped in the TIR, lithologies, alteration and weathering products are mapped in the VNIR and TIR, surface textures are mapped with TIR and radar, and topography and ground deformation are mapped with interferometric radar. Typically, remote sensing volcanologists must unravel the contributions of these phenomena to the signals measured over volcanic targets.

Remote sensing volcanologists make use of data from a variety of instruments and satellites, including the GOES (Imager and Sounder), NOAA Polar Orbiters (AVHRR and TOVS/HIS), TOMS, Landsat (MSS and TM), ERS (ATSR, radar), SPOT, RADARSAT, and ADEOS (AVNIR, OCTS, and radar). The recent launches of Landsat 7 (ETM), Terra (ASTER and MODIS), and EO-1 (Hyperion and ALI) have added multispectral TIR and VNIR imaging spectroscopy to the tools available to volcanologists.