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) 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.