While predicting damaging earthquakes remains currently impossible, it is important to lay a solid foundation for improving our ability to forecast them. Although the Visp area shows only moderate seismicity on a worldwide scale, the region offers an excellent opportunity to observe and study the preparation processes for a moderate to large event in the Alpine collision zone. The probability of observing a major earthquake in the next 40 years is high and the proposed project is a first step in studying its preparation. Moreover, it will allow us to set up a scientific base for detailed monitoring and analysis. Due to the limited size of the area where the next large earthquake in the Valais might occur, this region is one of the best natural observatories in Europe. To ongoing surveillance and seismic hazard assessment, the proposed project therefore adds two new elements: 1) interdisciplinary investigation and monitoring of short and long-term earthquake preparation processes at a regional scale, and 2) study of complex non-linear surface effects induced by seismic strong ground motion at a local scale.
COGEAR proposes research with a long-term perspective, including a follow-up study that will focus on assessing risk. The monitoring system is key. It is focused on the Valais and in particular on the epicentral areas of the 1755 and 1855 earthquakes, including the Rhone river plain at Visp and the Visper and Matter valleys. The following networks and sites are proposed in the project COGEAR:
Such a monitoring system will be innovative for the Swiss as well as the international scientific community, and will provide data of unique value and quality. We expect that these systems will be operational for many decades, with a high probability that they will monitor the next damaging earthquake in the Valais.