Tracking melt injection under the Mid-Atlantic Rift near Askja, central Iceland

Abstract

Despite the challenging sub-Arctic conditions, we have run a continuous year-round network at Askja since 2008. Thanks to experience gained over successive years, modifications to the network have allowed the number of stations that operate through the winter to increase. This has allowed extensive monitoring of the highly unusual lower crustal earthquakes beneath Askja, which are thought to be caused by melt moving into the lower crust from the mantle and has shown that they are a persistent ongoing feature. Travel time tomography has been completed showing a low velocity body beneath the caldera thought to be the magma chamber. The Askja network forms part of a larger network along the length of the Northern Volcanic Zone of Iceland, which will be used to constrain the structure of the entire rift.