Publications

Stereoscopic pictures returned by surface-based imaging systems can be used to reconstruct the topography of landing sites on Mars and other planets. Large surface relief with respect to distance and the large scale variation inherent in surface-based pictures produce problems in stereoscopic measurement very different from those presented by high altitude photography. Optical-mechanical scanning

The Apollo 11 LM landed approximately 20 km south-southwest of the crater Sabine D in the southwestern part of Mare Tranquillitatis ( fig. 3-1 ). The landing site is 41.5 km north-northeast of the western promontory of the Kant Plateau (ref. 3-1 ), which is the nearest highland region. The Surveyor 5 spacecraft is approximately 25 km north-northwest of the Apollo 11 landing site, and the impact cr

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 like. For example, when a lava flow solidifies (at temperatures near 1000°C) and cools throu

This is the second in a series of six reports that the U.S. Geological Survey published on the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the March 27, 1964, Magnitude 9.2 Great Alaska Earthquake and extended, as detailed investigations, through several field seasons. The 1964 Great Alaska earthquake was the largest earthquake in the U.S

The 1964 earthquake caused wide-spread damage to inhabited places throughout more than 60,000 square miles of south-central Alaska. This report describes damage to all communities in the area except Anchorage, Whittier, Homer, Valdez, Seward, the communities of the Kodiak group of islands, and communities in the Copper River Basin; these were discussed in previous chapters of the Geological Survey

The March 27, 1964, earthquake was accomp anied by crustal deformation-including warping, horizontal distortion, and faulting-over probably more than 110,000 square miles of land and sea bottom in south-central Alaska. Regional uplift and subsidence occurred mainly in two nearly parallel elongate zones, together about 600 miles long and as much as 250 miles wide, that lie along the continental mar

During the 1964 Alaska earthquake, tectonic deformation uplifted the southern end of Montague Island as much as 33 feet or more. The uplifted shoreline is rapidly being modified by subaerial and marine processes. The new raised beach is formed in bedrock, sand, gravel, and deltaic bay-head deposits, and the effect of each erosional process was measured in each material. Fieldwork was concentrated

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

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 factors contributing to the origin and reactivatio

The Murray fracture has been thought to extend ashore into the Transverse Ranges of California, but a geophysical study shows no evidence of structural continuity between these features. Instead, basement morphology typical of the Murray fracture zone ends where its known magnetic and bathymetric expression dies out. Similarly, east-west Transverse Range structures change direction so that they ar

Time residuals from 75-km segments of 18 crustal seismic-refraction profiles in the Basin and Range province are used to investigate the validity of the linear-regression model and to make large sample estimates of the variance in the travel time distributions.A formula for unbiased estimates of velocity uncertainty is derived, assuming a linear trend with distance for the variances of the travel-

Many cores raised from the Drake Passage are characterized by alternating zones of foraminiferal ooze and sandysilt. Cores raised from the East Pacific Rise are foraminiferal ooze or alternating siliceous and carbonate ooze. The uranium and thorium concentrations and isotopic ratios in foraminifers separated from these cores were measured by alpha-spectroscopy. 230Th in foraminiferal tests is foun