Maps/Report by USGS Scientists show underwater features of
Crater Lake in unprecedented detail
release June 1, 2001
by U. S. Geological Survey, News Release
New Maps/Report by USGS Scientists Show Underwater Features of
Crater Lake in Unprecedented Detail Ancient lava flows, volcanic
cones and landslides are some of the features below the surface
of Crater Lake that are depicted and explained in a report
available from the U.S. Geological Survey, Department of the
Interior. The geologic features of Crater Lake came to light in
July 2000, when USGS scientists mapped the floor of the lake in
unprecedented detail, using an ocean-exploration technique known
as high-resolution multibeam echosounding.
Crater Lake, the scenic showpiece of Crater Lake National Park
in southwestern Oregon, is the deepest lake in the United
States. It occupies a caldera in Mount Mazama, a
12,000-foot-tall volcano that erupted catastrophically, then
collapsed, about 7,700 years ago. The new survey determined that
the lake is 1,949 feet deep at its deepest point.
bathymetry data collected by USGS scientists gives researchers a
better understanding of the geologic history of Mount Mazama.
The two maps that make up the report use color-shaded relief to
show in detail a number of submerged volcanic landforms and
other features that formed in the caldera in the centuries
following the mountain's collapse. One map gives a bird's eye
view of the floor of the entire caldera, conveying how it would
look if the water of Crater Lake were removed. The other map
provides a series of perspective views of different volcanic
landforms rising from the floor. These include Merriam Cone, a
500-foot-tall volcano; the extensive base of Wizard Island; and
parts of the caldera's rim. Also revealed in detail are various
volcanic vents, ancient shorelines, sediment basins and debris
flows. An accompanying text summarizes the geologic processes
responsible for these features.
The 2-sheet report, titled "Bathymetry and Selected Perspective
Views of Crater Lake, Oregon," by James V. Gardner, Peter
Dartnell, Laurent Hellequin, Charles R. Bacon, and J.
Christopher Stone, U.S. Geological Survey; Larry A. Mayer,
University of New Hampshire; and Mark W. Buktenica, National
Park Service, is Water-Resources Investigations Report 01-4046.
The report is available for inspection only at USGS offices in
Menlo Park, California (345 Middlefield Rd.), Sacramento,
California (6000 J Street), and Carson City, Nevada (333 W. Nye
Lane, Room 103). The report also may be inspected at the USGS
libraries in Menlo Park, Calif., Denver, Colo., and Reston, Va.,
and at the USGS Earth Science Information Centers in Menlo Park,
The report may be purchased at cost from the USGS Branch of
Information Services, Box 25286, Denver, CO 80225-0286
(telephone 1-888-ASK-USGS). The price is $4.00 per copy plus
$5.00 per order for shipping and handling. Request must specify
report number "WRIR 01-4046" and should include a check or money
order payable to "Department of the Interior--USGS."
Additional information about Crater Lake and the new bathymetry
survey is available online from the Crater Lake Information
Clearinghouse at http://craterlake.wr.usgs.gov and the Pacific
Seafloor Mapping Project at http://walrus.wr.usgs.gov/pacmaps.
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