The work planned in this subproject changed significantly in response to the enhanced earthquake activity at Hengill at the western end of the SISZ. Rather than operating one semi-continous GPS station, we participated in the installation of 4 continously recording GPS stations in the Hengill area as described in Subproject 1. The equipment for these stations was bought from funding external to the PRENLAB-2 project, but PRENLAB-2 funding was used for the installation.
The planned static GPS measurements were also concentrated on the Hengill area. The static measurements have been conducted at regular intervals of few months since the beginning of the PRENLAB-2 project, and these show the continued expansion and uplift of the area of the enhanced earthquake activity .
PRENLAB-2 related work includes also static GPS measurements on the Reykjanes peninsula in 1998, that shows how left-lateral shear is continuously accumulating across the plate boundary in South Iceland . A study has also been conducted on how to relate crustal uplift, to the volume of magma/gas accumulation at depth in the crust . This is considerable of interest for the activity at Hengill, as one must understand how to relate the observed crustal deformation to changes that take place at deeper level in the crust, e.g. magma accumulation.