Eruption Style

Mt. Pinatubo is an Explosive volcano. It emmitts andesitic lava. When it is erupted it has very dangerous pyroclastic flows, due to its high viscosity. Before the eruption in 1991 there were several important river systems throughout Mt. Pinatubo. They were large and important ecosystems. After the eruption deep valleys were filled with pyroclastic deposits. The rivers have been clogged with sediment and the valleys have been faced with frequent lahars.