MARCA-GEHN, the archive of macroseismic data for four Central America countries

In the frame of the RIESCA Project, funded by AICS, 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 countries involved in the project, namely, Guatemala, El Salvador, Honduras and Nicaragua (GEHN). In 2019, the first prototypal version of an online tool named MARCA-GEHN was released: it combines in a database, easy to be consulted and with cartographic support, a reference earthquake catalog, and a preliminary digital macroseismic archive for a sector of Central America (CA). The database compilation started to establish a transnational, common, quality-checked archive of macroseismic observations, capable of documenting, validating, and eventually updating the earthquake parameters of damaging and destructive events reported in the main historical and instrumental catalogs. A better knowledge of the effects of past earthquakes, especially in the pre-instrumental era, is a fundamental step also for a more quantitative assessment of magnitude and causative fault sources, and for the upgrade of seismic hazard and risk estimates. The collection and critically analysis of original documental sources, and their organization into a public repository are processes that last longer than a few years long project. Thanks to European tools and expertise, and to the additional efforts provided by the local CA scientific communities, MARCA-GEHN has been updated in 2023. In the actual release of the database, about 70 earthquakes are given with the distribution of intensities observed at the sites, about 2200 intensity points referring to more than 1100 localities. We briefly present the main capabilities of the archive, some novelties introduced with respect to similar products, and discuss about future updates.