Physical Deformation at Guagua Pichincha

“Previous studies of deformation accompanying volcanic activity have yielded significant results mainly at basaltic volcanoes such as Kilauea in Hawaii, where eruptions have occurred frequently. There, slow inflation or swelling of the volcanic edifice has preceded activity as magma rises and accumulates within a reservoir a few kilometers beneath the summit, and more abrupt deflation commonly accompanies eruption of lava.” (Lipman and Mullineaux 1981)

The last accurate topographic map of the Guagua Pichincha complex was taken by an overflight on February 4, 2000. Subsequent flights taken since the resumption of activity have shown a bulge and graben within the preexisting crater at the summit. The crater is shown by the dotted line.

NOTE: The bulge is within the ~1.1km wide crater complex at the summit of Guagua, not on the eastern flank of the volcano. We have no measurements that would lead us to believe that the eastern flank is expanding any more than any other flank of the volcano. The dotted line on the deformation images is the crater complex rim, not the base of the volcano.

Elevation change, in feet, between consecutive topographic maps

within the summit crater complex: a) February 4, 2000 to October 7, 2000

b) October 7 to October 12

d) October 12 to October 19