Publications

We outline a simple method for estimating the cross-spectral matrix of coastal-trapped wave amplitudes,A, from a set of oceanographic observations. Specifically, we propose that A may be estimated by (M'M)-1M'UM(M'M)-1 where a prime denote conjugate transpose, U is the sample cross-spectral matrix of observations and M is a matrix which has the spatial form of the waves for columns. In...

The range of present knowledge on the subject of gas hydrates and related federal research programs was the topic of discussion at the National Workshop on Gas Hydrates, April 23–24. The intention of the meeting was to provide the impetus for an expanded and broader‐based national research program in both academia and government. Held at the U.S. Geological Survey National Center, Reston...

The island of Puerto Rico, in the northeast Caribbean, lies within a broad deformation zone between the Caribbean and North American plates. The simplest model for the tectonic setting of Puerto Rico has major strike-slip movement on nearly east-west lines in the vicinity of the Puerto Rico Trench coupled to a small counterclockwise rotation of a Puerto Rico block within the broader...

High-resolution seismic-reflection profiles off the lower Florida Keys reveal a multiple outlier-reef tract system ~0.5 to 1.5 km sea-ward of the bank margin. The system is characterized by a massive, outer main reef tract of high (28 m) unburied relief that parallels the margin and at least two narrower, discontinuous reef tracts of lower relief between the main tract and the shallow...

The stratigraphy of Late Quaternary geologic units beneath Long Island Sound (LIS) is interpreted from 3,500 km of high-resolution, seismic-reflection profiles supplemented by vibracore data. Knowledge gained from onshore regional geologic studies and previous offshore investigations is also incorporated in these interpretations. Glacial deposits overlie and nearly fill an Inner Lowland...

A conference on Antarctica: an Exploitable Resource too Valuable to Develop? took place at the Sir Robert Menzies Centre for Australian studies at the University of London in either late 1989 or early 1990. The papers were compiled into this small book (only 104 pages of text exclusive of useful appendices containing maps, texts of the Antarctic treaty and the Convention on the...

The West Antarctic rift system extends over a 3000 × 750 km, largely ice covered area from the Ross Sea to the base of the Antarctic Peninsula, comparable in area to the Basin and Range and the East African rift system. A spectacular rift shoulder scarp along which peaks reach 4–5 km maximum elevation marks one flank and extends from northern Victoria Land-Queen Maud Mountains to the...

No abstract available.

Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming [Revelle, 1983; Kvenvolden, 1988a; Nisbet, 1990]. We consider the response to sea-level changes by the...

Approximately 6100 km of 3.5-kHz echo-sounding profiles was correlated with a GLORIA side-scan sonar image of the mid-Atlantic United States (34??N, 70??W) lower slope-upper continental rise. The image allows us to map the major erosional and depositional features and to identify major processes that have shaped the area. Interpretation of GLORIA imagery and echo-sounding profiles...

The prediction of large-scale coastal change is an extremely important, but distant goal. Here we describe some of our initial efforts in this direction, using historical bathymetric information along a 150 km reach of the rapidly evolving barrier island coast of Louisiana. Preliminary results suggest that the relative sea level rise rate, though extremely high in the area, has played a...

This paper proposes a new definition of the groupiness factor, GF, based on the envelope of the incident-wave time series. It is shown that an envelope-based GF has several important advantages over the SIWEH-based groupiness factor, including objective criteria for determining the accuracy of the envelope function and well-defined numerical limits. Using this new GF, the variability of...