Publications

Reflectance measurements of selected rocks and soils over a wide range of illumination geometries obtained by the Imager for Mars Pathfinder (IMP) camera provide constraints on interpretations of the physical and mineralogical nature of geologic materials at the landing site. The data sets consist of (1) three small “photometric spot” subframed scenes, covering phase angles from 20° to 150°; (2) t

The Imager for Mars Pathfinder (IMP) acquired more than 16,000 images and provided panoramic views of the surface of Mars at the Mars Pathfinder landing site in Ares Vallis. This paper describes the stereoscopic, multispectral IMP imaging sequences and focuses on their use for digital mapping of the landing site and for deriving cartographic products to support science applications of these data.

Viking infrared thermal mapping and bistatic radar data suggest that the bulk density of the north polar erg material is much lower than that of the average Martian surface or of dark dunes at lower latitudes. We have derived a thermal inertia of 245–280 J m−2 s−1/2 K−1 (5.9–6.7×10−3 cal cm−2 s−1/2 K−1) for the Proctor dune field and 25–150 J m−2 s−1/2 K−1 (0.6–3.6×10−3cal cm−2 s−1/2 K−1) for the

The Mars Pathfinder (MPF) spacecraft landed on relatively young (late Hesperian-early Amazonian; 3.1-0.7 Ga) plains in Chryse Planitia near the mouth of Ares Vallis. Images returned from the spacecraft reveal a complex landscape of ridges and troughs, large hills and crater rims, rocks and boulders of various sizes and shapes, and surficial deposits, indicating a complex, multistage geologic histo

Two vastly different phenomena, impact and salt diapirism, have been proposed for the origin of Upheaval Dome, a spectacular scenic feature in southeast Utah. Detailed geologic mapping and seismic refraction data indicate that the dome originated by collapse of a transient cavity formed by impact. Evidence is as follows: (1) sedimentary strata in the center of the structure are pervasively imbrica

The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of

No abstract available.

No abstract available.

Average velocities for time intervals ranging from < 1 to 15 years were measured by tracking ice-surface patterns on sequential Landsat and European Remote-sensing Satellite synthetic aperture radar images. Velocities ofThwaites Glacier range from 2.2 km a−1 above the grounding line to 3.4 km a−1 at the limit of measurements onThwaites Glacier ice tongue. The glacier increases in velocity by about

The United States Geological Survey Flagstaff Field Center was founded by the late Eugene Shoemaker in 1963 as a research site for the new science of planetary geology. Flagstaffs clear air and high elevation made it a desirable location for telescope observations of the Moon and planets and nearby Meteor Crater was a superb training ground for the Apollo astronauts. There, and in the volcanic fie

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 Ellsworth Lands,

The George VI and Wilkins Ice Shelves are considered at risk of disintegration due to a regional atmospheric warming trend on the Antarctic Peninsula. Retreat of the northern margin of the George VI Ice Shelf has been observed previously, but the Wilkins Ice Shelf was thought to be stable. We investigated the positions of the northern fronts of these shelves from the literature and looked for chan