The AHEAD Portal: A Gateway to European Historical Earthquake Data

Abstract

The description of the seismicity of the European region is today fragmented into an increasing number of earthquake archives, databases, and catalogs related to individual countries or even to part of them. Therefore, the compilation of a comprehensive, European earthquake history requires dealing with a puzzle of partially overlapping, only partially public catalogs, the background of which is compiled according to varied schemes. One of the consequences is that earthquakes in the frontier areas are often interpreted in a conflicting way by the catalogs of the bordering countries. In the framework of the European Commission (EC), 2006–2010 Network of Research Infrastructures for European Seismology (NERIES) Project, the task of Networking Activity 4 (NA4) was defined precisely to conceive and develop solutions to bridge over these differences. NA4 promoted the cooperation among existing national online archives, and contributed establishing new regional online archives compiled according to common standards. As a result, a first release of the distributed European archive of historical earthquake data, for the time-window 1000–1899 and for the large earthquakes, was published in 2010. Special attention was devoted to retrieve the earthquake background information, that is, the results of historical earthquake investigation—referenced to as studies in the following -in terms of a paper, a report, a book chapter, a map, etc. As the most useful studies are those supplying a set of macroseismic data points (MDPs)- that is a list of localities (name and coordinates) with a macroseismic intensity assessment and the related macroseismic scale—a dedicated effort was addressed to make such data available. The Archive of Historical Earthquake Data (AHEAD) distributed archive was improved and updated in the frame of the 2010–2012 EC Project Seismic Hazard Harmonization in Europe (SHARE), Task 3.1 European earthquake database, with the contribution of a number of European institutions. For the time window 1000–1899, it was AHEAD (AHEAD Working Group) that supported the compilation of the SHARE European Earthquake Catalog (SHEEC; Stucchi et al., 2013). This paper describes the AHEAD portal (http://www.emidius.eu/AHEAD/; last accessed March 2014), and how it was conceived to network the local components of the distributed archive. Although local historical macroseismic databases usually supply one set of information for each earthquake, at a European scale an earthquake still might be described by several studies, available from different archives. The AHEAD portal inventories and gives access to multiple sets of information concerning each earthquake, and allows users to get comprehensive information about individual earthquakes, providing the answers to the following questions: 1. which sets of earthquake parameters (time, location, magnitude, magnitude type, maximum intensity, etc.) are available for each earthquake? 2. what is the background information, or supporting material, upon which each set of earthquake parameter determination is based?