Item talk:Q152171
Uplift, thermal unrest and magma intrusion at Yellowstone caldera
The Yellowstone caldera, in the western United States, formed approx640,000 years ago when an explosive eruption ejected approx1,000 km3 of material1. It is the youngest of a series of large calderas that formed during sequential cataclysmic eruptions that began approx16 million years ago in eastern Oregon and northern Nevada. The Yellowstone caldera was largely buried by rhyolite lava flows during eruptions that occurred from approx150,000 to approx70,000 years ago1. Since the last eruption, Yellowstone has remained restless, with high seismicity, continuing uplift/subsidence episodes with movements of approx70 cm historically2 to several metres since the Pleistocene epoch3, and intense hydrothermal activity. Here we present observations of a new mode of surface deformation in Yellowstone, based on radar interferometry observations from the European Space Agency ERS-2 satellite. We infer that the observed pattern of uplift and subsidence results from variations in the movement of molten basalt into and out of the Yellowstone volcanic system.
