Publications

Altitudes and relative ages of mare surface units were compared to test if a systematic correlation in height of lava eruption surfaces and age might reflect a corresponding increase in depth of the magma chamber with time; in addition the altitudes were studied to shed light on the time and place of warping of mare surfaces. The laser altimeter data from the Apollo missions and relative...

Six University of Wisconsin portable, continuously‐recording seismographs were operated for 3½ days in late 1976 in the Eastern Cordillera of Colombia in a 200‐km‐diameter array around Bucaramanga, where there are also three permanent stations of the Instituto Geofísico de Los Andes Colombianos. Twenty‐seven microearthquakes were recorded. Most can be well located. Only one event...

We appreciate the comments made in the discussion by Michael A. Collins, regarding our paper about the anomalously low salinity of water underlying Nantucket Island. However, we feel that in his effort to justify the mathematical approach for solving salt water intrusion problems, he has overlooked several of the major points in this paper. We will try to amplify these points to

No abstract available.

Large landslides in the Martian equatorial troughs have been investigated with respect to morphology, geologic structure of the troughs, time of emplacement, similarity to terrestrial landslides, and origin and mechanism of transport. Viking Orbiter images provided a base for morphologic analyses, mapping, crater counts, and volumetric considerations. Results showed that the morphologic...

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

No abstract available.

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

No abstract available.

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

Field experiments on beach-cusp formation were undertaken to document how the cuspate form develops and to test the edge-wave hypothesis on the uniform spacing of cusps. These involved observations of cusps forming from an initially plane foreshore. The cuspate form was observed to be a product of swash modification of an intertidal beach ridge as follows. A ridge, cut by a series of...

Six computer-generated seismic depth sections over the outer continental shelf and upper slope reveal that subhorizontal Lower Cretaceous reflectors continue 20 to 30 km seaward of the present shelf edge. Extensive erosion on the continental slope has occurred primarily during the Tertiary, causing major unconformities and retreat of the shelf edge to its present position. The precise...