For volcanologists these are busy times. The eruption on Sunday of Fuego in Guatemala came suddenly and its deadly pyroclastic flows have taken dozens of lives. Meanwhile, Hawaii’s Kilauea volcano has been providing drama for more than four weeks now. The two volcanoes are very different beasts. “Kilauea is fed from a mantle hotspot, erupting dry, hot basalts; Fuego is fed from a subduction zone, erupting sticky, wet magmas that tend to explode,” said Daniel Morgan, a geologist at the University of Leeds. With luck, the worst is now past for Fuego, but on Kilauea there is still concern about how the ending will play out.
In 1924 Kilauea produced a particularly dramatic finale, hurling massive blocks – weighing as much as 14 tonnes – out from its crater. This explosive episode was preceded by the crater’s lava lake draining away, and scientists are keeping a close eye on this eruption for similar behaviour. “If the level of the magma drops below that of the local water table at the summit for sufficient time, water can enter into the conduit and start a steam-driven explosive eruption,” explained Morgan. In this case the hope is that Kilauea’s uppermost pipes are clogged up, preventing fast draining of magma.
