10 April 2007: U.S. scientists have found that a major earthquake can immediately increase volcanic activities in the same region, adding a new impetus to a long-standing debate over whether earthquakes can trigger new volcanic eruptions. Scientists monitored two ongoing eruptions on Indonesia’s Java Island in May 2006 after a powerful 6.4-magnitude earthquake rocked the region.
“During that period, we found clear evidence that the earthquake caused both volcanoes to release greater amounts of heat, and lava emission surged to two to three times higher than prior to the tremor,” said Andrew Harris, the lead author of the study.
At the time of the earthquake, each volcano was being checked for changes in heat output by satellite sensors as part of a routine global “hot spot” monitoring effort that uses real-time satellite data from NASA’s Terra and Aqua satellites.
Maps of worldwide hot-spot activity are created with data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on these satellites, pinpointing locations where surface temperatures are much hotter than their surroundings.
The scientists combined the data with other details about the Indonesian volcanoes gathered by the satellites to analyze temperature and lava output rates over a 35-day period spanning the earthquake. The researchers are currently reviewing older MODIS hot-spot data, which extends back to 2000, to uncover additional earthquake-induced responses at erupting volcanoes.
The scientists are hoping they can identify patterns that might be used to build a model for forecasting earthquake-induced volcanic eruptions. The finding, based on NASA-satellite data, was published in the latest edition of the American Geophysical Research Letters.