Magnetic Field Measurements at Bardarbunga Dike Graben |
Morschhauser, A. (1), Rivalta, E. (1), Matzka, J. (1), Brown, M. (2), Adalgeirsdóttir, G. (2), Dahm, T. (1). |
(1) Helmholtz Centre Potsdam GFZ German Research Centre for Geoscienses, Potsdam, Germany, (2) University of Iceland, Reykjavík, Iceland |
In 2014 and 2015, the Bardarbunga volcano in Iceland produced a dike protruding about 45 km to its northeast. The magma erupted at two fissures, resulting in a lava field of 85 km2. Although dike propagation is well known thanks to seismic measurements, the cooling history and depth to the top of the dike is much less constraint. Here, we present our efforts to constrain these parameters using magnetic field measurements. On two field excursions in 2016 and 2017, we used a series of scalar and vector field repeat measurements to isolate the signal due to changes in the remanent and induced magnetization of the dike and its surroundings. The measurements were challenging for two reasons: First, the terrain is highly magnetic with strong topographic relief, demanding high positioning accuracy for repeat measurements, and second, the area was at high latitude and therefore the influence of the polar electrojets was potentially strong. We show that repeat measurements of high accuracy can be made in such a harsh terrain, and we present the (preliminary) results of our survey. |
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