The primary goal of the proposed research is to determine the relationship between the debris avalanche of Raung Volcano, Java, to explosive volcanism. The debris avalanche, with its run out length of 60 kilometers is one of the largest in Indonesia and perhaps in the world. It is well exposed and readily accessible. The deposit is interstratified with deposits of magmatic eruptions, some of which are probably deposits of lateral blasts similar to Mount St. Helens blast of May 18, 1980. The central question to be pursued is whether or not the debris avalanche caused an associated magmatic eruption, or a magmatic eruption caused the debris avalanche. This issue is poorly known scientifically and is important for solving more general problems about the development of pyroclastic surges and flows. It is also critical in assessing eruption hazards and development of evacuation and contingency plans in areas of large stratovolcanoes with steeply sloping sides.
