Geologic Hazards Science Center

Publications

Filter Total Items: 2,074
Publication Thumbnail
Year Published: 1971

Preliminary photointerpretation map of landslide and other surficial deposits of the Mount Diablo area, Contra Costa and Alameda Counties, California

The map shows the distribution of landslide and other surficial deposits by presenting the writer's best judgement regarding the origins of the various parts of the present landscape. It is based completely on the interpretation of aerial photographs through a stereoscope, which permits a three-dimentional relief model of the ground surface to be...

Nilsen, Tor H.
Preliminary photointerpretation map of landslide and other surficial deposits of the Mount Diablo area, Contra Costa and Alameda Counties, California; 1971; MF; 310; Nilsen, T. H.

Publication Thumbnail
Year Published: 1971

Geomagnetic polarity epochs: age and duration of the olduvai normal polarity event

New data show that the Olduvai normal geomagnetic polarity event is represented in Olduvai Gorge, Tanzania, by rocks covering a time span of roughly from 0.1 to 0.2 my and is no older than 2.0 my. Hence the long normal polarity event of this age that is seen in deep-sea sediment cores and in magnetic profiles over oceanic ridges should be called...

Gromme, C.S.; Hay, R.L.

Publication Thumbnail
Year Published: 1971

Pacific geomagnetic secular variation

A smooth field over the central Pacific for a million years indicates a nonuniform lower mantle of the earth.

Doell, Richard R.; Cox, A.
Pacific geomagnetic secular variation; 1971; Article; Journal; Science; Doell, R. R.; Cox, A.

Publication Thumbnail
Year Published: 1970

A computer program to trace seismic ray distribution in complex two-dimensional geological models

A computer program has been developed to trace seismic rays and their amplitudes and energies through complex two-dimensional geological models, for which boundaries between elastic units are defined by a series of digitized X-, Y-coordinate values. Input data for the program includes problem identification, control parameters, model coordinates...

Yacoub, Nazieh K.; Scott, James H.
A computer program to trace seismic ray distribution in complex two-dimensional geological models; 1970; USGS Unnumbered Series; Yacoub, Nazieh K.; Scott, James H.

Publication Thumbnail
Year Published: 1970

Map showing relative amounts of landslides in California

Radbruch, Dorothy H.; Crowther, Kenneth C.
Map showing relative amounts of landslides in California; 1970; OFR; 70-270; Radbruch, Dorothy H.; Crowther, Kenneth C.

Publication Thumbnail
Year Published: 1969

History of the geomagnetic field

Direct measurements of the direction and strength of the earth's magnetic field have provided a knowledge of the field's form and behavior during the last few hundreds of years. For older times, however, it has been necessary to measure the magnetism of certain rocks to learn what the geomagnetic field was...

Doell, Richard R.

Publication Thumbnail
Year Published: 1969

Geomagnetic reversals

Although decreasing rapidly, the earth's magnetic field is probably not now reversing.

Cox, A.
Geomagnetic reversals; 1969; Article; Journal; Science; Cox, A.

Publication Thumbnail
Year Published: 1969

The morphology and chronology of a landslide near Dillon Dam, Dillon, Colorado

Investigations were made of a landslide at the Dillon Dam site, Dillon, Colo., that included detailed laboratory and field analyses of the mineralogy, chemistry, and physical properties of landslide materials and the bedrock formations from which they were derived. These investigations provide an understanding of the relative importance of various...

Wahlstrom, E.E.; Nichols, T.C.

Publication Thumbnail
Year Published: 1968

Slope stability programs for the city of Rio de Janeiro and environs and the landslide disaster of the Serra das Araras escarpment, Brazil, 1967

Jones, Fred O.
Slope stability programs for the city of Rio de Janeiro and environs and the landslide disaster of the Serra das Araras escarpment, Brazil, 1967; 1968; OFR; 68-154; Jones, Fred Oscar

Publication Thumbnail
Year Published: 1967

Geomagnetic polarity epochs: Nunivak Island, Alaska

New paleomagnetic and potassium-argon dating measurements have been made of basalt flows from Nunivak Island, Alaska, with the following results. (1) The best estimate of the age of the Brunhes/Matuyama polarity epoch boundary is found to be 0.694 m.y. (2) The best estimate of the age of the Gauss/Gilbert boundary is 3.32 m.y. (3) Three normally...

Cox, A.; Dalrymple, G. B.

Publication Thumbnail
Year Published: 1967

Geomagnetic polarity epochs: new data from Olduvai Gorge, Tanganyika

The lower lava flow of Bed I in Olduvai Gorge, Tanganyika, carries natural remanent magnetization (NRM) having normal polarity. Thermal demagnetization experiments demonstrate the stability of this NRM. Thus the Olduvai geomagnetic polarity event, which was originally named from the upper lava flow in Bed I, is represented in its type locality by...

Gromme, C.S.; Hay, R.L.

Publication Thumbnail
Year Published: 1967

Geomagnetic polarity zones for icelandic lavas

Analysis of cores collected from a sequence of lavas in Eastern Iceland has made possible an accurate calculation of the average rate of reversal of the Earth's magnetic field.

Dagley, P.; Wilson, R.L.; Ade-Hall, J. M.; Walker, G.P.L.; Haggerty, S.E.; Sigurgeirsson, T.; Watkins, N.D.; Smith, P.J.; Edwards, J.; Grasty, R.L.