Activity overview

The project has successfully been carried out in accordance with the workprogramme. The individual subprojects have been carried out successfully in accordance with the general outlines in the workprogramme, as confirmed in reports on individual subprojects. Earth activity, seismic and volcanic, has been extremely high in Iceland during the time of the project. Therefore it was necessary to put much emphasis in enhancing the monitoring system and collection of data. Consequently, it was possible to study crustal processes related to earthquakes to an extent far beyond what was originally expected. The increased earth activity as well as scientific progress, not least of the PRENLAB projects, led to an increased interest and thus increased support of the government of Iceland for monitoring earthquake- and volcano-related crustal processes.

Successes in providing useful warnings have led to increased confidence of the public as well as of authorities of Iceland in the possibilities of seismology and related sciences in mitigating risks, as well as in the significance of the PRENLAB projects. The earth activity in Iceland led to slight shifts in the emphasis within individual tasks of the workprogramme in order to grasp the opportunities nature provided to carry forward the main objectives of the project, which are to understand better where, when and how earthquakes occur.

An earthquake sequence in the Hengill-Ölfus area in SW-Iceland (Figure 1) and associated deformation lead to concentration of the PRENLAB-2 activity in this area which, because of these events, became the most significant part of the natural laboratory during the first part of PRENLAB-2.

Two eruptions occurred in southern part of Iceland during the period of the project.

Two large earthquakes which occurred in the South Iceland seismic zone (SISZ), both magnitude 6.6 (Ms), near the end of the project period, were a test for the state of risk mitigation and earthquake prediction research in Iceland at present, and reveal new possibilities for the progress of such a research. These two earthquakes and related observed earth activity are of enormous significance for the progress of many parts of the PRENLAB-2 project far beyond its objectives.

  

Figure 1: Iceland, with its rift zones and volcanic zones, which delineate the mostly NS elongated mid-Atlantic ridge through Iceland. The EW plate divergency across the mid-Atlantic ridge and upwelling mantle plume below Iceland (Hotspot) are responsible for the seismicity and the volcanism. The observational network for continuous monitoring, used in the project, is shown. Volcanic zones are shown in yellow, i.e. the very active eastern volcanic zone (EVZ), the less active western volcanic zone (WVZ), and Reykjanes peninsula (RP). Large earthquakes occur along the EW elongated South Iceland seismic zone (SISZ) and in the Tjörnes fracture zone (TFZ) off the north coast. Glaciers are shown in bluish-white. The Hengill-Ölfus area, frequently mentioned in this report, is at the triple junction between SISZ, RP and WVZ.