Publications

A 1:62,500-scale black-and-white map identifying some 2,000 landslides of various types in Santa Cruz County, California, has been converted to a digital-map database that can be acquired from the U.S. Geological Survey over the Internet or on magnetic tape.

The Pacific margin of North America is one of the most complicated regions in the world in terms of its structure and present day geodynamic regime. The aim of this work is to develop a better understanding of lithospheric structure of the Pacific Northwest, in particular the Cascadia subduction zone of Southwest Canada and Northwest USA. The goal is to compare and contrast the...

Profile development indices for soils developed in moraines and outwash near Twin Lakes and in outwash near Leadville support the correlation of moraines with subdued morphology and two high outwash terraces with the Bull Lake glaciation (ca. 130-160 ka) and the correlation of hummocky moraines and two low outwash terraces with the Pinedale glaciation (ca. 14-47 ka). Elsewhere in the...

The U.S. Geological Survey is using Landsat imagery from the early 1970s and mid- to late 1980s/early 1990s to analyze glaciological features, compile a glacier inventory, measure surface velocities of outlet glaciers, ice streams and ice shelves, determine coastline change and calculate the area and volume of iceberg calving in Antarctica. Ice-surface velocities in Marie Byrd and...

Landslides are common in sttep mountainous areas of Puerto Rico where mean annual rainfall and the frequency of intense storms are high. Each year, landslides cause extensive damage to property and coccasionally result in loss of life. Average population density is high, 422 people/km2, and is increasing. This increase in population density is accompanied by growing stress on the natural

During the late Eocene, the formerly quiescent geological regime of the Virginia Coastal Plain was dramatically transformed when a bolide struck in the vicinity of the Delmarva Peninsula, and produced the following principal consequences:The bolide carved a roughly circular crater twice the size of the state of Rhode Island (~6400 km2), and nearly as deep as the Grand Canyon (1.3 km deep...

High-resolution Galileo imaging has provided important insight into the origin and evolution of grooved terrain on Ganymede. The Uruk Sulcus target site was the first imaged at high resolution, and considerations of resolution, viewing geometry, low image compression, and complementary stereo imaging make this region extremely informative. Contrast variations in these low-incidence angle...

This chapter contains two papers that summarize the performance of engineered earth structures, dams and stabilized excavations in soil, and two papers that characterize for engineering purposes the attenuation of ground motion with distance during the Loma Prieta earthquake. Documenting the field performance of engineered structures and confirming empirically based predictions of ground...

The papers in this chapter reflect the broad spectrum of issues that arise following a major damaging urban earthquake-the regional economic consequences, rehousing problems, reconstruction strategies and policies, and opportunities for mitigation before the next major seismic event. While some of these papers deal with structural or physical science topics, their significant social and...

No abstract available.

A side-scan sonar survey was conducted of Monterey Canyon and the San Gregorio fault zone, off shore of Monterey Bay. The acoustic character and morphology of the sonar images, enhanced by SeaBeam bathymetry, show the path of the San Gregorio fault zone across the shelf, upper slope, and Monterey Canyon. High backscatter linear features a few kilometers long and 100 to 200 m wide...

More than 36,000 km of Deep Seismic Sounding (DSS) profiles have been collected in China since 1958. However, the results of these profiles are not well known in the West due to the language barrier. In this paper, we summarize the crustal structure of China with a new contour map of crustal thickness, nine representative crustal columns, and maps showing profile locations, average...