Why does kilauea erupt?
Volcanoes vary a great deal in their destructive power. Some volcanoes explode violently, destroying everything in a mile radius within minutes, while other volcanoes seep out lava so slowly that you can safely walk all around them. The severity of the eruption depends mostly on the composition of the magma. Gas vents from Kilauea Volcano in Hawaii The first question to address is: why does the magma erupt at all? The erupting force generally comes from internal gas pressure. The material that forms magma contains a lot of dissolved gases — gases that have been suspended in the magma solution. The gases are kept in this dissolved state as long as the confining pressure of the surrounding rock is greater than the vapor pressure of the gas. When this balance shifts and vapor pressure becomes greater than the confining pressure, the dissolved gas is allowed to expand, and forms small gas bubbles, called vesicles, in the magma. This happens if one of two things occurs: * The confining pre
