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Photographs, maps, and other images from the Three Sisters region of Central Oregon.
(Top) 1996–2000 interferogram draped over a 30-m DEM and showing uplift centered a few kilometers (miles) west of South Sister volcano. (Bottom) Geochemical data on top of the 1996–2000 interferogram. The columns show chloride (Cl) and sulfate (SO4) concentrations at sampled springs.
(Top) 1996–2000 interferogram draped over a 30-m DEM and showing uplift centered a few kilometers (miles) west of South Sister volcano. (Bottom) Geochemical data on top of the 1996–2000 interferogram. The columns show chloride (Cl) and sulfate (SO4) concentrations at sampled springs.
About 130 mm (5 inches) of peak uplift from 1995 to 2001 is shown in this interferogram in the Three Sisters Wilderness. Magma accumulating at about 7 km (about 4.5 mi) depth is the likely cause of uplift. The area of uplift, about 20 km (12 miles) in diameter, is almost entirely within the wilderness area.
About 130 mm (5 inches) of peak uplift from 1995 to 2001 is shown in this interferogram in the Three Sisters Wilderness. Magma accumulating at about 7 km (about 4.5 mi) depth is the likely cause of uplift. The area of uplift, about 20 km (12 miles) in diameter, is almost entirely within the wilderness area.
Three Sisters volcanoes (left to right - South, Middle, and North) viewed from the south, Oregon. Foreground rhyolite Newberry flow is one of most recent eruptive units (2.2 ka).
Three Sisters volcanoes (left to right - South, Middle, and North) viewed from the south, Oregon. Foreground rhyolite Newberry flow is one of most recent eruptive units (2.2 ka).
Remnant of Villard Glacier is in cirque below. Thick summit lava flow makes up "Glisan Pinnacle," which overlies hundreds of thin rubbly lava flows that are intercalated with red-oxidized agglutinate and scoria falls exposed on 800-m- (2600-ft-) high face below. Flows that form ridge at upper right are thicker than those on most of edifice.
Remnant of Villard Glacier is in cirque below. Thick summit lava flow makes up "Glisan Pinnacle," which overlies hundreds of thin rubbly lava flows that are intercalated with red-oxidized agglutinate and scoria falls exposed on 800-m- (2600-ft-) high face below. Flows that form ridge at upper right are thicker than those on most of edifice.
Three Sisters annotated photograph viewed from south to North from Broken Top, Oregon.
Three Sisters annotated photograph viewed from south to North from Broken Top, Oregon.
Geologic Map of Three Sisters Volcanic Cluster, Cascade Range, Oregon
Geologic Map of Three Sisters Volcanic Cluster, Cascade Range, Oregon