Interferogram reveals deformation of Peulik volcano, Alaska, 1996-1998
Mount Peulik is a small volcano in the Aleutian volcanic arc about 550 km southwest of Anchorage. There are only two reports of historical activity at Mount Peulik, in 1814 and 1852. This interferogram represents deformation between October 1996 to September 1997. It shows a striking bull's-eye fringe pattern centered on the southwest flank of the volcano. Six fringes that represent about a total of about 17 cm (6.7 inches) of uplift map out the deformation pattern in considerable detail. Other interferograms for the period from September 1997 to September 1998 reveal one more fringe, corresponding to about 3 cm (1.1 inches) of additional uplift.
From these images alone, scientists are able to deduce that a magma body about 6.6 km (4.1 miles) beneath the volcano expanded by about 50 million cubic meters (65 million cubic yards) during 1996-98. The average inflation rate was about 3 million cubic meters per month from October 1996 to September 1997, peaked at 5 million cubic meters per month during June 26-October 9, 1997, and dropped to 1 million cubic meters per month from October 1997 to September 1998.
More information (including images) about Mount Peulik volcano is available from the Alaska Volcano Observatory.
Lu, Z., Wicks, C. Jr., Dzurisin, D., Power, J.A., Moran, S., and Thatcher, W. (2001), Magmatic inflation at a dormant stratovolcano: 1996-98 activity at Mount Peulik volcano, Alaska, revealed by satellite radar interferometry, Journal of Geophysical Research, in press.