Earthquake risk is high in much of the southern half of Alaska, but it is not the same everywhere. This map shows the overall geologic setting in Alaska that produces earthquakes. The Pacific plate (darker blue) is sliding northwestward past southeastern Alaska and then dives beneath the North American plate (light blue, green, and brown) in southern Alaska, the Alaska Peninsula, and the Aleutian Islands. Most earthquakes are produced where these two plates come into contact and slide past each other. Major earthquakes also occur throughout much of interior Alaska as a result of collision of a piece of crust with the southern margin.
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(Click on map for a larger version - .pdf file, 312K.
A rolled version of this map is available from:
USGS-Earth Science Information Center
4230 University Drive, Room 101
Anchorage, AK 99508
907-786-7011
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SOURCES OF INFORMATION
Additional data and references to earthquake, faulting, and
seismicity in Alaska can be found in Plafker and others (1994),
Page and others (1991), and Taber and others (1991). The material
on this map was modified chiefly from Plafker and others (1994),
and earthquake epicenters were from the Alaska Earthquake Information
Center, and cover the interval from 1899-1994. The location
of earthquake epicenters and faults is approximate.
Plafker, G., Gilpin, L.M., and Lahr, J.C., 1994, Neotectonic
map of Alaska: in Plafker, G., and Berg, H.C., eds., The
Geology of Alaska: Boulder, Colorado, Geological Society
of America, Decade of North American Geology Volume G-1,
1 sheet, scale: 1:2,500,000.
Page, R.A., Biswas, N.N., Lahr, J.C., and Pulpan, H.,
1991, Seismicity of continental Alaska: in Slemmons, D.B.,
Engdahl, E.R., Zoback, M.D., and Blackwell, D.D., eds.,
Neotectonics of North America: Boulder, Colorado, Geological
Society of America, Decade Map Volume 1.
Taber J.J., Billington, S., and Engdahl, E.R., 1991, Seismicity
of the Aleutian arc: in Slemmons, D.B., Engdahl, E.R., Zoback,
M.D., and Blackwell, D.D., eds., Neotectonics of North America:
Boulder, Colorado, Geological Society of America, Decade
Map Volume 1.
This map is preliminary and has not been reviewed for conformity
with U.S. Geological Survey editorial standards or the North
American Stratigraphic Code. Any use of trade, product, or
firm names is for descriptive purposes only and does not imply
endorsement by the U.S. Government.
Open File Report 95-624 |
