Publications

No abstract available.

Annual losses in the United States, Japan, Italy, and India have been estimated at 1 billion or more each. During the period 1971-74, nearly 600 people per year were killed by landslides worldwide; about 90 percent of these deaths occurred in the Circum-Pacific region. From 1967-82, 150 people per year died in Japan as a result of slope failures. In the United States, the number of...

The Fourier power spectra of geomagnetic component values, synthesized from spherical harmonic models, have been computed for circular paths on the Earth's surface. They are not found to be more useful than is the spectrum of magnetic energy outside the Earth for the purpose of separating core and crustal sources of the geomagnetic field. The Fourier power spectra of N and E geomagnetic...

The internal properties within and adjacent to fault zones are reviewed, principally on the basis of laboratory, borehole, and seismic refraction and reflection data. The deformation of rocks by faulting ranges from intragrain microcracking to severe alteration. Saturated microcracked and mildly fractured rocks do not exhibit a significant reduction in velocity, but, from borehole...

The most common types of mass movements that form landslide dams are rock and soil slumps and slides; mud, debris, and earth flows: and rock and debris avalanches. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snow melt, and earthquakes. Most landslide dams are remarkable short-lived. In a sample of 63 documented cases, 22 percent of the...

No abstract available.

No abstract available.

The origins of paleoflood hydrology in the United States can be traced back to the beginning of the 19th century, when windgaps and watergaps in the Applachians were believed to have been eroded by extraordinary floods as large lakes that were ponded behind the ridges rapidly drained. Sediment evidence for extraordinary floods was evoked several decades later when glacial sediments in...

No abstract available.

In 1984, the U.S. Geological Survey conducted a detailed geologic analysis of two nuclear test craters at Enewetak Atoll, Marshall Islands, on behalf of the Defense Nuclear Agency. A multidisciplinary task force mapped the morphology, surface character, and subsurface structure of two craters, OAK and KOA. The field mapping techniques include echo sounding, sidescan sonar imaging, single...

Electric currents in long pipelines can contribute to corrosion effects that limit the pipe's lifetime. One cause of such electric currents is the geomagnetic field variations that have sources in the Earth's upper atmosphere. Knowledge of the general behavior of the sources allows a prediction of the occurrence times, favorable locations for the pipeline effects, and long-term...

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd...