Drilling volcanoes

Eichelberger, John

'Introductory geology textbooks always contain a cutaway view of the inside of a volcano. Although eroded volcanic structures provide some factual basis, the primary source for such diagrams is most often the author's merged impressions of similar drawings in other textbooks. But in reality, the only way to look inside an active volcano is to drill into it. Although difficult, such journeys should be made, given the rich rewards for understanding the processes and environment of volcanic conduits.' 'The history of drilling volcanoes is brief but exciting. During repeated penetrations of Kilauea Iki lava lake in Hawaii, temperatures reached over 1100ªC, a record high. Spray from a lava fountain had formed a pond in a pre-existing crater that was 100m deep, so that two decades after the eruption, the melt lens was still tens of meters thick. The molten rock was 'cored' with the drill by chilling the lava to glass ahead of the advancing bit with copious cooling water (4), producing beautiful columns of black glass studded with green olivines. These, however, were very shallow holes, and the 'magma' had already lost its water through eruption.' 'Successful volcano drilling projects must carefully address issues of safety, funding, environmental protection, property ownership, subsurface targeting, directional drilling in an extreme environment, and public relations. Each of these issues has been overcome at one time or another in other scientific drilling projects, but they have yet to be tackled together in an international project at a single, well-watched, recently active volcano. When they are, the results will permanently change textbook depictions of how volcanoes work and will greatly improve the basis for eruption predictions. Such efforts may ultimately allow drilling into the source chamber itself, sampling live magma quenched in situ. These samples could perhaps answer the age-old question of how the magma 'still' works, that is, how magmas as sluggish as molten granite, the key ingredient of continental crust, fractionate so rapidly and cleanly.'

Drilling volcanoes

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