Revista Geológica de América Central, 52: 129-149, 2015 DOI: 10.15517/rgac.v0i52.19033 ISSN: 0256-7024 ACTIVIDAD HISTÓRICA Y ANÁLISIS DE LA AMENAZA DEL VOLCÁN TURRIALBA, COSTA RICA HISTORIC ACTIVITY AND HAZARD ANALYSIS OF TURRIALBA VOLCANO, COSTA RICA Gino González1, 2, 3*, Raúl Mora-Amador1, 2, 3, Carlos Ramírez1, 2, 3, Dmitri Rouwet4, Yemerith Alpizar1, Cristian Picado2, 3 & Rolando Mora2 1Centro de Investigaciones en Ciencias Geológicas (CICG), Universidad de Costa Rica 2Escuela Centroamericana de Geología, Universidad de Costa Rica. 3Red Sismológica Nacional (RSN), Universidad de Costa Rica. 4Istituto Nazionale di Geofisica e Vulcanologia (INGV), sezione di Bologna, Italia *Autor para contacto:
[email protected] (Recibido: 31/07/2011; aceptado: 18/09/2014) ABSTRACT: The historic activity of Turrialba volcano was studied based on traveler’s reports and newspapers of the 19th century. In 1864-1866, the volcano was in a period of magmatic eruptions which can be subdivided in two stages: pre-eruptive and eruptive. Ash fall reached distances of ~115 km covering an area of 3400 km2. By means of GIS, we estimated how a similar magmatic eruption as this, could affect the present population and infrastructure, and we con- clude that the ash would fall in the most populated areas of Costa Rica, which is important as a prevention measure and an analysis of future risk decision-making. In 2005, Turrialba volcano increased its seismic activity, gas emissions and acid rain, which affected the S, SW and W sectors of the volcano. Afther more than a century without eruption, on 5 January 2010 phreatic activity resumed, with emissions of non-juvenile ash which reached San José.