Researchers pinpoint volcanic hazards

Volcanologists at UB have used computer models to estimate the effect of extremely fast-moving volcanic mudflows on a key industrial town in Mexico and analyzed satellite data to produce geologic "X-rays" that can predict weak spots on the surface of a volcano.

The results of their research were presented today in Toronto at the annual meeting of the Geologic Society of America.

Extremely fast-moving volcanic mudflows could inundate and destroy a large part of a key industrial town near Colima volcano in Mexico sometime in the next 10 years, according to volcanologist Michael Sheridan, professor and chair of the Department of Geology, and Yvonne Paul, a senior who is first author on the study.

And that's the least-extreme scenario if the volcano reaches the climactic stage of its eruption cycle, which is expected during the next decade, according to their research.

"The largest resulting mudflow that we calculated would destroy much of Atenquique with a wall of water and debris 200 feet high," said Sheridan.

Atenquique is a major paper- and lumber-producing center; the main rail connection from the Pacific to Central Mexico passes through the town.

Sheridan noted that newer, industrial towns near volcanoes often are located in more dangerous areas than those settled by indigenous peoples.

"In modern towns, everything is new and there is no cultural memory of the volcano, especially if it erupts in a 100-year-cycle, like Colima," he said. Indigenous peoples, on the other hand, tend to retain that memory through generations.

The researchers applied to Colima volcano a mathematical model that predicts the width, travel distance and course of debris flows of various potential sizes that result from volcanic eruptions. The model was developed by the U.S. Geological Survey and is based on data from other existing volcanoes. Paul, a geology major, performed the calculations. "The results I got are consistent with different runout lengths that have been known to occur at this volcano," said Paul. "Even the smallest predicted mudflow would wipe out most of the village."

A second study has been used to produce a volcanic-hazards map for Citlalpetl, an active volcano about 80 miles west of Vera Cruz, Mexico.

Preliminary results on Citlalpetl confirm the hypothesis that large amounts of certain materials on a volcano's surface represent soft spots that easily could trigger avalanches.

This is the first time that remote detection of these materials has been used in cooperation with public-safety officials to develop a volcanic-hazards map.

Such data will help the UB researchers develop a probability curve of the frequency for catastrophic events resulting from volcanoes, such as landslides and avalanches, that could be used for hazard mitigation by public officials.

The project is funded by a $300,000 grant from the National Aeronautics and Space Administration.