UNDERSTANDING THE PRE-HISPANIC HUMAN-VOLCANO INTERACTIONS IN A TROPICAL CRITICAL ZONE DURING THE HOLOCENE

Critical zones in tropical environments are rich in resources such as water, food and construction materials especially near active volcanoes. In Central America, people have lived near active volcanic centers for thousands of years and learned to take advantage of these resources. Understanding how Pre-Hispanic societies lived in this type of critical zones and interacted with volcanoes provides us with insights on how to reduce the negative impact derived from volcanic activity in modern cities. In this multidisciplinary research, we focus on two case studies in Costa Rica near Poás and Turrialba volcanoes, which are currently active, in order to obtain a comprehensive view of human-volcano interactions through time. We use a methodology based on historical accounts, geological and archeological fieldwork, remote sensing techniques, geomorphological characterization of past (Pre-Hispanic) and present land use analysis. The northern Poás region represents a case of a less developed Pre-Hispanic society, which subsisted mainly on hunting and gathering activities, had no permanent settlements and was probably affected by the activity of the Hule and Río Cuarto Maars. In spite of their vulnerability and lack of infrastructure, they used geomorphology to their advantage to achieve natural protection. Over time modern societies have developed infrastructures taking advantage of the geodynamic potential of the region to produce energy. The Guayabo National Monument near Turrialba volcano represents a cultural peak in Pre-Hispanic societies in Costa Rica. Archeological remains and structures at this site indicate that this society had a good understanding of physical and geological processes and were therefore able to take advantage of resources for water and food supply, construction, protection, as well as hazard prevention and mitigation. Here the use of new technologies to study the site, resulted in high quality geomorphology data as well as past and present land use approaches. Finally, this study helps to establish how some locations near volcanic edifices are more prone to be affected by volcanic hazard than others and why this data should be included in volcanic risk assessment and land planning processes.