Seismic hazard assessment is traditionally based on seismicity. It is assumed that where there have been earthquakes in the past then there will be more in the future and vice versa. Previous EC (and other) work by the proposers has shown that this approach is fundamentally flawed, especially in regions such as Greece which are not located on a plate boundary and that, without also measuring strain, accurate assessments of seismic hazard cannot be made.
This proposal, which addresses the Commission's priority the safety of the citizen from environmental risks, seeks funds to identify areas of high seismic hazard in Greece using strain derived from high precision GPS positioning coupled with that estimated from geological data and records of seismic activity. This is something that is crucial for the economic security of those hving and working within Greece, the country with by far the greatest frequency of earthquakes in Europe. In order to achieve this, an overall strain model for Greece will be constructed from the results of previous work and new GPS observations will be undertaken. As part of the study a novel approach to GPS data collection based on a few receivers moving more or less continuously around the region will be researched along with its associated processing methods - especially to improve our ability to model atmospheric refraction errors and to determine integer ambiguities. This has important implications for the future use of GPS for engineering and other practical applications as it offers an alternative to the prohibitively costly, and inflexible, alternatives of permanent arrays and epoch campaigns respectively.
The proposal comes from a pan-European consortium with a proven record of success and collaboration in the use of GPS for geodynamic purposes, and includes those with both geodetic and geophysical expertise. It links directly with past work by this and other groups. In particular it follows directly from an EU funded project (led by the Project Coordinator) which established a sixty-six station monitoring network in Central Greece. The work proposed here will, however, utilise GPS networks estabhshed by other partners (and others), as well as published strain results, to widen the area of interest to the whole nation, whilst also focusing on areas of specific seismic hazard such as the Gulf of Korinthos - where past work has shown that there might be a significant shortfall in the release of strain through earthquakes. Moreover it will make full use of the permanent GPS infrastructure currently being established in the region. The specific objectives are to :
(a) identify areas of high seismic hazard in Greece,
(b) obtain an all-embracing assessment of strain accumulation throughout Greece, and in specifically targeted areas,
(c) develop new and more efficient operational and computational procedures for the use of GPS to deliver high quality positional data within regional and global control networks, and
(d) improve the understanding of the relationship between strain accumulation and seismic hazard assessment by integrating geodetically derived strain data with the existing seismic catalogue and other geological data.
The project is precompetitive in the sense that the GPS processing research will yield results that will be the basis of future GPS software products.
Funding SchemeCSC - Cost-sharing contracts
2600 GB Delft
OX1 3PR Oxford