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William Hung Kan Lee

Publications and source records attributed to William Hung Kan Lee.

12 recordsLinked to original sources
USGS1980

1979 annual index of current earthquake literature

In the past several years, earthquake research has been greatly accelerated in China, Japan, USSR and the United States. Presently, about 3,000 earthquake-related publications (including meeting abstracts) are produced yearly. In order to keep up with this current literature, a computer-based bibliographic system was implemented as part of a research project called 'Worldwide Earthquake Research Databases' under the direction of W.H.K. Lee. This bibliographic system is called the Current Earthquake Literature (CEL) Database. From this database, a bimonthly author index and annual index (including author, keyword and address listings) are prepared. Because there are large amounts of data entries, errors are unavoidable and any corrections from the readers are welcome.

Open-File Report↗
USGS1979

A preliminary study of the Coyote Lake earthquake of August 6, 1979, and its major aftershocks

The August 6, 1979 earthquake (magnitude 5.7 + 0.2) was located about 1 km east of the Calaveras fault trace near Coyote Lake, at a depth of about 10 km. The spatial distribution of the aftershocks in the first 15 days and the focal mechanism of the main shock and selected aftershocks suggest that faulting took place primarily to the southeast of the main shock along a 25-km segment of the Calaveras fault zone at a depth of 4 to 12 km. The motion was right-lateral strike-slip along a nearly vertical fault plane. Discontinuous surface rupture was observed along a 14.4-km length of the recently active trace of the fault southeast of Coyote Lake, but no surface faulting was seen in the epicentral area. A maximum 5-mm fault offset was recorded near San Felipe Lake, about 16 km south of the main shock. There was no prominent foreshock activity. The cumulative number of aftershocks (N) versus magnitude (M) could be described by the equation log N= 3.33 - 0.75 M, in the magnitude range between 1 and 3.5. The number and size of aftershocks appeared to be much less than that expected for a main shock of magnitude 5.7.

California↗
USGS1976

Preliminary investigations on computational methods for solving the two-point seismic ray-tracing problem in a heterogeneous and isotropic medium

Two-point seismic ray tracing is an important problem in seismology. In this report, we study this problem by first deriving the differential equations governing seismic wave propagation between two end points in a 3-dimensional heterogeneous and isotropic medium. We then formulate three numerical schemes to solve the two-point ray-tracing problem. In the first method, introduced originally by R. L. Wesson, the second order ray equations are reduced by the central difference approximation to a set of simultaneous non-linear equations, which are then solved by Newton's method. In the second method, the second order ray equations are reduced to a set of first order equations which are solved by using an adaptive finite difference method introduced by M. Lentini and V. Pereyra. The third method, due originally to L. Euler uses a sum to approximate the integral for the travel time which are solved directly for the minimum time path. This formulation may be shown to be equivalent to Wesson's method. We programed Wesson's method for a 3-dimensional inhomogeneous velocity medium, and also applied Lentini and Pereyra's method for a 2-dimensional linear velocity model. Our programs are tested for constant velocity, and linear velocity in one, and two, space variable models. Both programs give satisfactory answers in comparison with known analytic solutions, and with respect to each other.

Open-File Report↗
USGS1975

Catalog of earthquakes in the Lake Mead area, Nevada-Arizona, for the period from July 10, 1972, to December 6, 1973

Lake Mead is one of the world's largest reservoirs and was created by the construction of Hoover (formerly Boulder) Dam in the 1930's. Earthquakes were felt in September 1936, a few weeks after Lake Mead had reached its annual peak of about 100 m in maximum water depth. At the request of the Bureau of Reclamation, the Coast and Geodetic Survey began seismic investigations in 1937. A quadripartite net of short-period seismographs was installed in 1942 and operated until the early 1950's. Results of these investigations were reported by Mead and Carder (1941), Jones-(1944), Carder (1945), Carder and Small (1948), and Carder (1970).

Arizona, Nevada↗