Subaqueous Pyroclastic Deposits from Tambora and Krakatau Volcanoes, Indonesia

在1815年印度尼西亚坦博拉火山大爆发期间，可能有多达30立方千米的火山碎屑流进入了海洋。类似地，在1883年的事件中，火山碎屑或未知性质的碎屑流在距离喀拉喀托火山15公里处形成了厚达30米的海底沉积物。地面火山碎屑流与海洋之间相互作用的性质尚不清楚，但对于火山成因海啸的产生和共烟灰形成的相互竞争的模型至关重要。PIs将研究坦博拉（1815年）和喀拉喀托（1883年）的海底沉积物，使用坦博拉地区现有的活塞和重力岩芯，以及从喀拉喀托周围浅海收集的新岩芯。研究结果将用于：1)测试坦博拉火山和喀拉喀托火山喷发期间海啸和共烟灰形成的现有模型；2)建立火山碎屑流和海水相互作用的一般模型；3)描述由这种相互作用形成的水下沉积物的性质。这些结果对于理解这些事件的喷发过程和提供火山碎屑沉积的现代类似物具有重要意义，这些类似物可以应用于地质记录中的古代收敛边缘序列。该项目由国家地理学会共同资助。

During the great explosive eruptions of Tambora in Indonesia as up to 30 km3 of pyroclastic flows may have entered the ocean during the 1815 event. Similarly, pyroclastic or debris flows of unknown character formed up to 30 m thick submarine deposits up to 15km from the Krakatau volcano in the 1883 event. The nature of the interaction between subaerial pyroclastic flows and the sea is poorly understood but is critical to competing models of volcanogenic tsunami generation and of the formation of co-ignimbrite ash. The PIs will study the submarine deposits from tambora (1815) and Krakatau (1883) by using a suite of existing piston and gravity cores from the Tambora area and by collection of new cores from the shallow seas around Krakatau. The results of the study will be used to 1) test existing models for the generation of tsunamis and co-ignimbrite ash fall during the Tambora and Krakatau eruptions, 2) develop general models for the interaction of pyroclastic flows and seawater, and 3) characterize the nature of subaqueous deposits formed by such interactions. These results will be significant in terms of understanding the eruptive processes of these events and providing modern analogues of volcaniclastic sedimentation that can be applied to ancient convergent margin sequences in the geologic record. The project is being co- funded with National Geographic Society.