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W. C. Schwab

Publications and source records attributed to W. C. Schwab.

At least 37 records · Page 2Linked to original sources
USGS1999

Archive of 15 cubic inch water gun data collected during USGS Cruise ALPH98013, New York Bight, 10-22, September, 1998

Background This CD-ROM contains copies of the navigation and field water gun subbottom data collected aboard the F/V Alpha & Omega II. The USGS Cruise ALPH98013 was conducted from 10-22 September, 1998, and is a collaborative involving the U.S Army Corps of Engineers, New York District and the United States Geological SurveyCoastal and Marine Geology Program, Woods Hole Field Center. In 1995, the USGS, in cooperation with the U.S Army Corps of Engineers (USACOE), New York District, began a program to generate reconnaissance maps of the sea floor offshore of the New York-New Jersey metropolitan area, one of the most populated coastal regions of the United States. The goal of this mapping program is to provide a regional synthesis of the sea-floor environment, including a description of sedimentary environments, sediment texture, sea-floor morphology, and geologic history to aid in understanding the impacts of anthropogenic activities, such as ocean dumping. This mapping effort differs from previous studies of this area by obtaining digital, sidescan sonar images that cover 100 percent of the sea floor. This investigation was motivated by the need to develop an environmentally acceptable solution for the disposal of dredged material from the New York - New Jersey Port, by the need to identify potential sources of sand for renourishment of the southern shore of Long island, and by the opportunity to develop a better understanding of the transport and long-term fate of contaminants by investigations of the present distribution of materials discharged into the New York Bight over the last 100+ years (Schwab and others, 1997). Sidescan-sonar data collected during USGS Cruises Seax95007 and Seax96004 (May 1995 and May 1996, respectively) were digitally mosaicked to provide a base suitable for use in Geographic Information Systems of the New York Bight Apex region. During USGS Cruise Alph98013, supplemental sidescan sonar and seismic reflection data were collected within the New York Bight Apex region, primarily to augment the seismic reflection portion of the mapping project. Additional sidescan sonar and seismic reflection data were collected east of the Seax95007 and Seax96004 survey areas. These data abut sidescan sonar and seismic reflection data collected off the Southern Long Island shoreline during USGS Cruises Dian96040, Dian97011, and Dian97032 (September 1996, May 1997, October 1997, respectively).

Open-File Report↗
USGS1996

Sediment distribution on a storm-dominated insular shelf, Luquillo, Puerto Rico, U.S.A.

A sea-floor mapping investigation designed to assess the sediment distribution, the movement of the nearshore sand supply, and the fate of sediment eroded from the shoreline was conducted using high-resolution sidescan-sonar, seismic reflection, and sediment sampling techniques on the northern insular shelf of Puerto Rico, off the town of Luquillo. Sea-floor structures and the distribution of sediment texture and composition suggest that regional oceanographic processes result in a net offshore direction for cross-shelf sediment transport on the middle and outer shelf during storms. If these same processes are active on the inner shelf, mapping results indicate that this sediment is not transported seaward of a series of east-west trending Pleistocene-age eolianite ridges that outcrop on the middle shelf. The eolianite ridges may act as natural dams, preventing the removal of sediment from the nearshore area. Sand deposits behind the "dams" are up to 20 m thick on the shoreward flank of the ridges.

Puerto Rico↗
USGS1995

Geometry of sandy deposits at the distal edge of the Mississippi Fan, Gulf of Mexico

Sidescan sonar provides a map of the seafloor that has greatly improved the understanding of depositional processes on modern deep-sea fans (e.g. Mutti and Normark 1991). Here, we present a sidescan-sonar mosaic from the eastern Gulf of Mexico that images the distal reaches of a channel on the Mississippi Fan and the deposits associated with it (Fig. 41.1). This area is one of several deep-sea fan systems that had not previously been imaged by high-resolution sidescan systems. The mosaic highlights the complexity of the spatial relationships of channels and deposits at ends of channels on this large, modern, passive-margin deep-sea fan (Figs 41.2 and 41.3).

Mississippi↗