Assessing the Volcanic Threat of Central American Volcanoes

José Luis Palma, William Rose and Rüdiger Escobar-Wolf

Department of Geological Engineering and SciencesMichigan Technological University

Outline

• Introduction to Central American volcanoes

• Calculation of Hazard, Exposure and Threat scores

• Results and comparison with some well known U.S. Volcanoes

• Discussion on Vulnerability

• Conclusions

IntroductionCentral America is one the most volcanically active regions of the world. Through Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama, there are 80 Holocene volcanic centers of which 27 have exhibited historic activity.

Map of Volcanoes in Central America

Quantifying Volcanic Threat

The volcanic threat is quantified using the ranking system developed by Ewert et al. (2005, 2007) as part of the Framework for a National Volcano Early Warning System in the United States.

Ewert et al. 2005. An Assessment of Volcanic Threat and Monitoring Capabilities in the United States: Framework for a National Volcano Early Warning System.USGS open-file report 2005-1164.

Ewert 2007. System for Ranking Relative Threats of U.S. Volcanoes. Natural Hazards Review v.8 p.112-124.

Quantifying Volcanic Threat

#var 5 4 3 3 3 2 5 total=25 variables (0-10) (0-4) (0-3) (0-3) (0-oo) (0-2) (0-oo)

High threatVery High threat

Volcanic Threat of Central American Volcanoes

High threatVery High threat

Volcanic Threat of Central American Volcanoes

Vulnerability

Volcanic hazards are not the most important issue in Central America.

Even among natural hazards, volcanoes are not the one that is in most peoples minds (Hurricanes, Earthquakes, Landslides…)

In many places in Central America, poverty, health and other social issues are huge and compelling, and they are simply more important issues for most people.

Population was calculated using LandScan’s database (LandScan 2007. Oak Ridge National Laboratory)

Population density around selected volcanoes

Population density around volcanoes

Map of Volcanoes in Central America

In total, more than 20 million people live within 30 km from volcanic centers in Central America, which is about 50% of the total population.

Vulnerability

(a) life expectancy at birth; (b) % aged 15 and above 1995-2005, in the case of the U.S. this value was estimated differently; (c) combined gross enrolment ratio for primary, secondary and tertiary school; (d) literacy rate and school enrolment combined; (e) PPP= purchasing power parity, income.

Following Wisner et al. 2003, the vulnerability of a country to a natural hazard can be considered as the capacity of the country to anticipate, deal with, resist and recover from the impact of the hazard.

Comparison of the Human Development Index (HDI) between countries in Central America and the United States for 2005 (HDR 2007/2008).

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Reducing the risk

Conclusionso NVEWS’s methodology to rank hazardous volcanoes helps to focus the attention and effort on those volcanoes with highest threat.

o At least 22 volcanoes in Guatemala, El Salvador, Nicaragua and Costa Rica are classified as Very High Threat Volcanoes based on the NVEWS-US ranking system.

o Further work is needed to include more volcanoes in the database. Particularly, more field work must be carried out in order to improve mapping of volcanic areas and our knowledge about past eruptive activity.

o Vulnerability to volcanic eruptions in Central America is relatively high due to the high population density around volcanic centers and other socio-economic aspects.

o Geophysical/geological studies aimed at understanding the behavior of individual volcanoes, a well as the implementation of appropriate volcano monitoring, are fundamental steps towards the reduction of the volcanic risk and the likelihood of a disaster.