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 Mount
Adams stands astride the Cascade Crest some 50 kilometers due east of
Mount St. Helens. The towering stratovolcano (3,742 Meters - 12,276 Feet)
is marked by a dozen glaciers, most of which are fed radially from its
summit icecap. In the High Cascades, Mount Adams is second in eruptive
volume only to Mount Shasta, and it far surpasses its loftier neighbor
Mount Rainier (which is perched on a pedestal of Miocene granodiorite).
Adams's main cone exceeds 200 cubic kilometers, and at least half as much
more was eroded during late Pleistocene time form earlier high-standing
components of the compund edifice: peripheral basalt adds another 70 cubic
kilometers or so. |
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 During
the past one million years, numerous volcanic vents were active throughout
south-central Washington, from Vancouver to Goldendale. Most were probably
active for relatively short times ranging from days to tens of years.
Unlike Mount Adams, which has erupted repeatedly for hundreds of thousands
of years, these vents typically did not erupt more than once. Rather, each
erupting vent built a separate, small volcano, and over time a field of
numerous overlapping volcanoes was created. Clusters of these vents define
the Mount Adams, Indian Heaven, and Simcoe Mountains volcanic fields. In
addition, the Goat Rocks volcanic center lies 30 kilometers (18 miles)
north of Mount Adams. The Mount Adams and Indian Heaven fields have been
the most active recently; the Simcoe field and the Goat Rocks center have
not erupted for hundreds of thousands of years.
Location: Washington
Latitude: 46.206 N
Longitude: 121.49 W
Height: 3,742 Meters (12,276 Feet)
Type: Stratovolcano
Number of eruptions in past 200 years: 0
Latest Eruptions: More than 3,500 years ago 2 ... No more than
1,000 or 2,000 years ago 3.
Present thermal activity: Fumaroles emitting steam and hydrogen
sulfide in the crater area.
Remarks: Debris flows are lastest events... Appears to consist of
a group of several superimposed volcanic cones. Summit crater has
extensive sulfur deposits that were formerly mined.
Seismic Activity: Not very active, but increasingly
busier
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