Thermal mapping of Icelandic geothermal surface manifestations with a drone

Abstract

Rapid advances and developments in drone technologies have made mapping of geothermal surface manifestations doable and routine. In this study a DJI Matrice 210 drone, equipped with optical and thermal cameras, successfully maps some 1-4 km2 per day. Deliverables are an orthomosaic aerial and digital surface models (DSM) and a thermal reflectance map in °C. Data gathered from relatively low altitude flights, no more than 250 meters above ground surface, yields orthomosaic resolutions of only few centimeters/pixel and thermal resolutions of 20-30 cm. The thermal imagery is manipulated to be effectively processed to a map and ran through atmospheric corrections to maximize accuracy in °C. In this paper, thermal maps collected in four Icelandic locations are shown to produce lineaments of geothermal importance simply by ignoring all temperatures below a certain threshold. With this approach N-S oriented and a few hundred-meter-long structures in Svartsengi are inferred. The 1973 Eldfell eruption on Heimaey island in S-Iceland is still emitting heat to surface, inferring the thick basaltic lave pile deposited 45 years ago is yet to be fully solidified. The Geysir hot spring area thermal map is confirming previously published N-S orientation of the field main upflow zone, complemented with new warm surface areas and vivid convection cells in the hot water bowls of Strokkur and Geysir eruptive hot springs. The east flanks of Snæfellsjökull, a glaciated stratovolcano, are suspected to be heated by a deep seated and currently hidden boiling geothermal reservoir, by cross correlating high elevation vegetation growth, gaps in the snow cover and gently warm grounds.

Publication
At 44th Workshop on Geothermal Reservoir Engineering
Steinar Laenen
Steinar Laenen
PhD Candidate Theoretical Computer Science

My research interests are spectral graph theory, graph clustering, and unsupervised learning