Mechanism of the 1991 eruption of Hekla from continuous borehole strain monitoring

摘要: VOLCANOES erupt when the pressure in a magma chamber several kilometres below edifice overcomes strength of intervening rock. Seismic activity may accompany and precede eruptions, allowing (in favourable circumstances) location movement to be traced. Ground deformation near volcanoes can provide more direct evidence for movement, but continuous monitoring is necessary ensure that all essential aspects an eruption are recorded. Here we report dilatational strain data collected continuously during January 1991 Hekla volcano by five borehole strainmeters located 15–45 km from volcano. The record upward propagation magma, as well deflation deep reservoir. In only 30 minutes forced open conduit surface depth ∼4km. Although other might behave differently, our results suggest possibility using measurements monitor formation at sites, perhaps providing short-term warnings impending eruptions.