Report on laboratory testing of shallow sediments, Middle Atlantic Outer Continental Shelf

Abstract

This report contains the results of geotechnical engineering testing on cores taken by the U.S. Geological Survey to evaluate the characteristics of the sea floor within the Baltimore Canyon Trough area. The coring took place in September, 1977 aboard the R/V ANNANDALE. During the cruise (AN-01-77), 20 vibracores were taken at 17 stations across the Continental Shelf off the coast of New Jersey (Figure 1). Table 1 shows the station locations, the water depths at each station, and the core lengths. The objective of the study was to obtain a set of representative index properties as well as strength and compressibility data on sediments from across the shelf in the Baltimore Canyon Trough area. It was anticipated that these data, although of a reconnaissance rather than a site-specific nature, would provide a useful indication of the engineering properties of these sediments. Ultimately, these data may be used for preliminary design applications and the assessment of potential hazards. In this report, the results are presented without any interpretation. An overall evaluation of all data collected during the study, including those contained in this report, presently is underway. Users of this report should be cautioned not to take these test results out of context. Two factors must be borne in mind. The first is that these tests were done on somewhat disturbed samples compared with those obtained through high-quality sampling programs onshore. Much disturbance is inevitable offshore but the significance of the disturbance on these test results has not yet been evaluated. The second factor is that these data are only part of the total set available from this project. A complete analysis of all data may lead to conclusions that are different from those based on this set of data only. The tests reported herein were performed by Geotechnical Engineers Inc., 1017 Main Street, Winchester, Massachusetts 01890, under Contract 14-08-0001-16232 of the U.S. Geological Survey. Richard Brown and Charles Osgood performed the engineering properties tests. Sally A. Wood of the U.S. Geological Survey handled the transfer of vibracores between the U.S. Geological Survey and Geotechnical Engineers Inc. and, also, assisted in the preparation of this report.