Data access

Work which started within the PRENLAB project of creating an earthquake database with easy accesss has continued and accelerated during PRENLAB-2. The database structure used is INGRES.

This database now contains SIL network seismic data since 1991 which can be accessed through the Internet, by search in a simple relational database table. This table has hypocenter and magnitude information on all SIL measured earthquakes since July 1991 that have been manually checked, approximately 140000 earthquakes. Search options for area, magnitude and time are provided.

The preparatory work for a general easy accessible relational database for all seismic data is completed and the inclusion of data in the database is in good progress.

Included in the database is already now or will be within short:

• Information based on historical information. This information has been gathered over the years and will be inserted into the database.

• Information on instrumentally measured earthquakes from 1926 to 1991. Available parameter data for earthquakes during the period 1926-1973 has been extracted from catalogues and is currently being inserted into relational database tables. Information on earthquakes that were felt but not recorded is also inserted into the tables.

• Information on SIL parameter data, 1991-present. The data have been checked and updated to ensure compatible processing from different recording systems. The insertion of parameter data, both observed and derived, into relational database tables is nearly up-to-date. Information on approximately 140000 earthquakes is now accessible through a standardized SQL database.

• Information on station parameters, such as coordinates, instrument characteristics and time corrections at each respective time of measuring. Relational database tables have been developed.

Beside preparing this general database much work has been carried out in providing the various other subprojects with earthquake data, in accordance with the progress of the research work.