• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: EARTH BRIEFS; Etna; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.669.1729; http://geoinfo.nmt.edu/publications/periodicals/litegeology/24/lite-geo_24_2002.pdf

Earthquakes are one of nature’s most destructive forces. However, small earthquakes associated with volcanic eruptions can be very useful as a predictor of eruptive activity, and can warn scientists, emergency managers, and the public that a big eruption may be about to begin. For instance, the recent large eruption of Mount Etna, Italy’s highest and most vo-luminous volcano, was preceded by the largest swarm of earth-quakes seen at this volcano in the last 20 years. Increased earth-quake, or seismic, activity was observed on Mt. Etna starting on July 13, 2001. Over a two-day period, more than 2,500 earth-quakes were recorded, many of which were felt in nearby towns. Warnings were issued. On July 17, a major flank eruption began, generating explosive activity and lava flows from five separate fis-sure vents on the volcano’s flank. The lava flows destroyed roads and structures, and ash from explosive activity fell in towns up to 25 kilometers away. A nearby international airport had to be closed because ash was covering runways and obscuring visibility. Ash is also dangerous to aircraft engines. Why are earthquakes associat-ed with volcanic activity? Magma movement within the upper 10 kilometers of the earth stresses the crust, generating movement that radiates elastic waves to the Camera recording volcanic eruptions on the outer rim of Mt. Erebus, Antarctica. Images of eruptions are used to help interpret seismic activity in the volcano.