Robert P. Sharp

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Fretted and chaotic terrains are members of a larger family of lowland terrains on the Martian surface. They have formed in equatorial and midnorthern latitudes, within areas reasonably proximate to the extensive volcanic fields of that region. Both are relatively recent developments. Fretted terrain is characterized by extensive, smooth, lowland plains(More)
BACKGROUND Refractive surgery and videokeratography have allowed us to study the effects on visual performance of relatively large changes in corneal aberration structure induced by surgical changes in corneal shape. METHODS We quantified in one eye of nine normal and 23 radial keratotomy patients, the area under the log contrast sensitivity function(More)
doi: 10.1130/0091-7613(1996)024<0766:SRATRD>2.3.CO;2 1996;24;766-767 Geology Robert P. Sharp, Dwight L. Carey, John B. Reid , Jr., Pratigya J. Polissar and Michael L. Williams and Reply Sliding rocks at the Racetrack, Death Valley: What makes them move?: Comment Email alerting services cite this article to receive free e-mail alerts when new articles(More)
Landscapes are created by exogenic and endogenic processes acting along the interface between the lithosphere and the atmosphere and hydrosphere. Various landforms result from the attack of weathering and erosion upon the highly heterogeneous lithospheric surface. Landscapes are dynamic, acutely sensitive to natural and artificial perturbation. Undisturbed,(More)
An assemblage of huge parallel troughs, individually up to 200 km wide and hundreds of kilometers long, forms a belt 500 km wide extending for 2700 km E 15øS through the Tithonius Lacus-Coprates region of equatorial Mars. Some troughs are closed depressions more than 3 km deep, and the maximum trough depth may approach 6 km. These troughs, heading just(More)
Mariner 6 and 7 photographs reveal two types of uncratered terrain on Mars. These are descriptively termed chaotic and featureless. Chaotic terrain is younger than cratered terrain and displays features strongly suggestive of slump and collapse. The speculation is offered that it may be an expression of geothermal developments within Mars that only recently(More)
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