Publications

At the IUGG Assembly at Vancouver during August 1987 new definitive geomagnetic reference field (DGRF) models to degree 10 for 1945, 1950, 1955, and 1960 were adopted by IAGA. Before these new DGRF models were accepted, the author developed a trend and trigonometric model (old trig model) based on the models IGRF 1945, IGRF 1950, IGRF 1955, IGRF 1960, DGRF 1965, DGRF 1970, DGRF 1975, DGRF 1980, an

Efficient mitigation of natural hazards requires a spatial representation of the risk, based upon the geographic distribution of physical parameters and man-related development activities. Through such a representation, the spatial probability of landslides based upon physical science concepts is estimated for Cincinnati, Ohio. Mitigation programs designed to reduce loss from landslide natural haz

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Thirty-nine outcrop samples of mudstones, siltstones, and limestones were collected for source-rock evaluation of the sedimentary column in Vanuatu.  Twenty-nine samples showing the least evidence of oxidation were selected for total organic analysis from the Miocene Matanui Group and Port Sandwich Formation in Malakula, and from the Miocene Ilava, Peteao, and Pelapa Formations in Espiritu Santo.

Three distinct carbonate deposits have been identified on the slope and adjacent sea floor of the southwestern Florida Platform: (1) reef talus, recognized by shape and location, found on the upper slope of the Yucatan Channel and also east of the Marquesas Keys; (2) hemipelagic sediments, with complex sigmoid-oblique bed forms, filling the intervening gap between the channel and Keys and forming

Deep seismic reflection and magnetic data suggest that the Gulf of Maine is underlain by four crustal blocks of differing reflection and magnetic character. Two of these blocks, the Gulf of Maine fault zone and adjacent central plutonic zone, can be correlated with Avalonian rocks in southern New England and New Brunswick. The boundary between them, the Fundy fault, projects onshore near the Ponka

A bored and encrusted late Pleistocene ooid grainstone was recovered from the seafloor at a depth of approximately 40 m on the outer continental shelf of eastern Florida. Ooid cortices are dominantly bimineralic, generally consisting of inner layers of radial magnesian calcite and outer layers of tangential aragonite. Ooid nuclei are dominantly rounded cryptocrystalline grains, although quartz gr

Slumps and sediment-gravity flows have been identified in Holocene glaciomarine sediment on declivities less than 1.3 degrees on the Gulf of Alaska continental shelf. Geologic and geotechnical investigation suggest that the processes responsible for these slope failures are earthquake and storm-wave loading, coupled with cyclic degradation of the sediment-shear strength. We propose that the failur

Slope failures and subsequent mass movements have been identified in Holocene glaciomarine sediment on declivities less than 1.3° on the Alsek prodelta, Gulf of Alaska. Isolated collapse features cover less than 10 percent of a nearshore sand deposit, in water depths less than 40 m. In contrast, sediment gravity flow deposits (disintegrative failures) cover more than 95 percent of a clayey silt de

No abstract available.

No abstract available.

No abstract available.