A recent study in geophysics has shed new light on the formation of the volcanic Hawaiian Islands. Most people know that the islands of the Aloha State grow due to undersea volcanic eruption; molten rock released deep on the ocean bottom cools and hardens, forming a mountain on the seabed. As the process continues the mountain grows, eventually breaking the sea surface as the beginning of an island. Each of the islands in the Hawaiian chain was formed in this way.But the islands share other common geological features, the cause of which are not immediately obvious, as well as the underlying mechanism for their creation, and the perpetuation of the basaltic magma flow that is their source.
The study-a collaboration between the Laboratoire de Géophysique Interne et Tectonophysique in Grenoble, France, the Laboratoire de Sciences de la Terre de France and the US Geological Survey Hawaiian Volcano Observatory in Hawaii-uses finite-element computer modeling, to investigate the mechanics of the islands’ formation process.
The model was first based off of and constructed using a year’s worth of earthquake events in the island chain. Next the model was verified against over one thousand seismic data from the Kilauea volcano. The hind cast run of the model indicates that when the islands reach a large enough mass, the force of their weight may actually rupture the ocean bed, creating new channels for magma to flow and create new islands.