Marca-gehn, a prototype macroseismic archive of four central america countries

In the frame of activities of the RIESCA Project, funded by the Italian Agency for Development Cooperation, the Seismology Working Group (SWG) agreed to build up a prototypal archive of macroseismic data points for the four Central America countries involved in the project, namely, El Salvador, Guatemala, Honduras, and Nicaragua. The objective of this collection is to establish a transnational, common, quality-checked macroseismic archive, for documenting, validating, and eventually updating the earthquake parameters of damaging and destructive events. The new earthquake parameters, supported by documented observations, can be used to update the regional earthquake catalogues and enter into more reliable fault/area source characterisation for seismic hazard purposes. Further, the seismic histories at the site may serve as benchmarks for local response analyses in metropolitan areas. With collaborative efforts, the procedure for selecting and inputting the data into working repositories was defined and realised in 2017: the first data collection adopted basic Google™ tools. During 2018, the RIESCA SWG uploaded and updated about 2030 intensity datapoints (IDPs) of some dozens of earthquakes, following codified revision phases. In 2019, we released the first online prototypal archive, named MARCA-GEHN (Macroseismic Archive of Central America-Guatemala, El Salvador, Honduras, Nicaragua, V.1.0), based on the MIDOP (Macroseismic Intensity Data Online Publisher) tools. The present MARCA-GEHN release (V.1.6, September 2020) allows the queries by earthquake and by locality, with interactive maps and seismic histories at more than 1080 sites. We will present the general features of the database and describe the more interesting case studies among the earthquakes collected. MARCA-GEHN is open to collaborative efforts for its further improvement and refinements.