Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/29516
This study used optical remote sensors to identify surface hydrothermal alteration and thermal anomalies in the Sveifluháls-Krýsuvík high-temperature geothermal field. The study area is located in a volcanic fissure swarm in the central part of Reykjanes peninsula, in southwest Iceland. The area is characterized by intensive surface alteration, steam vents, mud pots, and hot springs. Multispectral Landsat and ASTER satellite images were used to identify hydrothermal alteration minerals and thermal anomalies. A hyperspectral image from Hyperion was used for the analysis of absorption features. Spectral analysis from the visible (VIS) to the short wavelength infrared (SWIR) allowed the identification of possible sulfur, iron oxides, and montmorillonite. A time series analysis of thermal anomalies using the nighttime satellite images from 2002 to 2017 detected extinct surface hydrothermal activity southwest of the study area, and a thermal anomaly possibly affected by crustal deformation in the southeast. In Seltún area, thermal infrared (TIR) images acquired by a camera on a drone were taken and compared with ground measurements; the aim was assessing the accuracy of the TIR images regarding the distance between the camera and the ground. The TIR image taken at 30m elevation was used to calculate radiative heat flux; values were in same order of magnitude than the heat flux estimated by using ground temperature measurements. This study provides insights for monitoring natural or induced changes on the surface geothermal activity in other geothermal fields.
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