New satellite imagery detects previously hidden magma chambers

Nature : Usually with volcanoes, the surface subsides around them because of the draining of magma-filled chambers in the ground beneath. But magma may pool in chambers far from any active volcano, according to a new study. Using satellite radar data and geodetic surveys, Ian Hamling of GNS Science in New Zealand and his colleagues were able to distinguish an unexpected rise in the ground in the Taupo Volcanic Zone of New Zealand’s North Island. Moreover, the ground appears to have been rising for more than a half century and at an ever-increasing rate—from about 5 mm/year in the 1950s to some 12 mm/year by the mid 2000s. However, the researchers say the magma increase does not necessarily mean an eruption is imminent. Moreover, similar processes have probably been going on all over the world; it is only now that instruments have been developed to detect them.