Publications

The present method of using constant secular variation rates to forecast magnetic components at a given site or to forecast spherical harmonic coefficients is known to be inaccurate. A new predictive method using trend and trigonometric functions fitted to known past values is used to extrapolate for a few years into the future. This provides an improvement over the usual linear extrapolation meth

No abstract available.

The slopes above streams and rivers are subjected to a variety of processes that cause them to recede and retreat from the river or stream channel. These processes, collectively called mass wasting, can be classified according to rapidity of movement and according to the type of materials that are transported. Gravity is the force behind all such downslope movement. Factors that enable the force o

The detailed behaviour of the geomagnetic field during reversals is documented by palaeomagnetists to constrain models of the geomagnetic dynamo. Reversals are studied by measuring the magnetic remanence preserved in rocks to obtain both the direction and intensity of the ancient magnetic field.

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 projections of corr

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 landslide dams

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 landslide-relat

Many techniques are available for reducing landslide hazards; 27 are described in this paper. Prerequisites for the successful use of these techniques are hazard information understandable to nongeologists and adequate communication of this information to those who will, or are required to, use it. It is concluded that certain factors needed to ensure the lasting effectiveness of these techniques

The collapse of the north face of Mount St. Helens on May 18, 1980, and the debris avalanche that resulted blocked outflow from Spirit Lake and Coldwater and South Fork Castle Creeks. Spirit Lake began to increase in size and lakes began to form in the canyons of Coldwater and South Fork Castle Creeks. Coldwater and Castle Lakes would have overtopped their respective blockages in late 1981 or earl

An inconvenience attending traditional use of associated Legendre functions in global modeling is that the functions are not separable with respect to the two indices (order and degree). In 1973 Merilees suggested a way to avoid the problem by showing that associated Legendre functions of order m and degree m+k can be expressed in terms of elementary functions asPmm+k(θ)=sinm(θ)∑ki=0amkicos(iθ)whe

We have produced a regional seismic slope-stability map and a probabilistic prediction of landslide distribution from a postulated earthquake. For liquefaction-induced landslides, in situ measurements of seismically induced pore-water pressures have been used to establish an elastic model of pore pressure generation. -from Authors

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 components