Insar interferogram depicting Mt. St. Helens deformation (surface e...
Detailed Description
LOS = Line of Sight
Top: ERS-1/2, track 156, interferometric stack of Mount St. Helens, Washington, composed of 36 interferograms spanning preeruptive 1992-2001 period. Inset shows location of stack. Locations of major features referred to in the text are labeled. Image shows three areas of subsidence in debris-avalanche deposit—1 (Johnston Ridge), 2 (Coldwater), and 3 (Elk Rock).
Bottom: RADARSAT standard mode 2 ascending interferometric stack of Mount St. Helens, Washington, composed of nine interferograms spanning coeruptive 2004-5 time period. Stack clearly shows line-of-sight lengthening (subsidence) centered on Mount St. Helens which, most likely reflects deformation of the ground surface associated with removal of magma from within the volcano as it was erupted on the surface.