ABSTRACT

Astronomical observatories are vulnerable to geological activity, hence it is necessary to consider the impact on the telescope facilities, but also on supporting facilities at the observatories and on local/ regional communication and infrastructures. In this work, only direct hazards to telescopes have been considered, in particular those affecting the structural design of telescopes, namely lava flows, volcanic ashfall and seismicity. The analysis was carried out at four world-class observatories, namely Roque de Los Muchachos (La Palma, Canary Islands, 28.75°N, 17.89°E, 2400 m.a.s.l.), El Teide (Tenerife, Canary Islands, 28.3°N, 16.51°E, 2380 m.a.s.l.), Paranal (Chile, 24.62°S, 70.4°E, 2620 m.a.s.l.) and Mauna Kea (Hawaii, 19.82°N, 155.47°E, 4130 m.a.s.l.) and the candidate site of Cerro Ventarrones (Chile, 24.35°Ss, 70.2°E, 2200 m.a.s.l.). A common methodology was used to characterize the geological hazard, expressed in terms of probabilities of occurrence in the next 50 years, recalling that this period of time corresponds to the expected lifetime of a large telescope.