Observation of the effects of the subglacial volcano eruption underneath the Vatnajökull glacier in Iceland with ERS-SAR data

Abstract

The Vatnajökull is Europe's largest glacier with an area of 8300 km² and an ice sheet up to 1000 m thick. Iceland has many periodically active volcanoes most of which are coverded by ice. The latest eruption took place between September 29 and October 13, followed by a flooding on November 5 and 6, 1996. A fissure was formed having a total length of appr. 11 km. It is surrounded by the Bárðarbunga, Hamarinn and Grímsvötn volcanoes. Due to the remote location of the eruption and bad weather conditions only a limited observation from ground or by plane was possible. ERS-2 - and later on ERS-1 and ERS-2 - gave the unique capability to supplement the lack of information. The German Remote Sensing Data Centre acquired, processed and further analyzed the ERS data in a very short period of time and made the information available to Icelandic partners via internet. The effort was a contribution to the accepted ESA AO2-project "Monitoring of natural changes of land surface in Iceland by the use of ERS1/2 SAR data and other remote sensing systems". Both amplitude and phase information were utilized to achieve the interpretation results. As the data were precisely orthorectified a quantitative analysis could be performed to estimate the dimensions of the fissure and the amount of melting water. The ERS data further allowed to localize possible areas effected by the expected flooding. The presented activities proved that ERS can significantly contribute to the monitoring of volcanic eruptions and the prediction of their possible consequences.