http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Suspended sediment on the upper Texas continental shelf
Hydrographic and transmissivity data and substrate samples were used to examine the hydrography, the bottom nepheloid layer (BNL) and the grainsize distribution of the substrate on the upper Texas continental shelf. Hydrographic data collected in March 1982 on one alongshore and four cross-shelf sections show the advection of mid or inner shelf water onto the outer shelf. Vertical sections of temperature, salinity and sigma-t show that the density structure on the inner shelf is governed by the salinity distribution while on the outer shelf the temperature distribution dominates the density structure. Transmissivity vertical sections show that a BNL is present across the shelf. On the inner shelf, surface nepheloid layers are present and, at the shelf edge, intermediate nepheloid layers are present. Substrate grainsize analyses show that two modes are usually present; a fine to very fine sand mode, and a clay mode. The clay mode indicates that present day deposition is occurring. Linear correlation analyses done on the BNL properties height and total suspended load and on substrate and hydrographic properties indicate that the BNL is not simply linked to either the substrate or the hydrography. Examination of long-term current meter data collected by other investigators shows that bottom currents on the shelf have an offshore component much of the time. This provides a mechanism for transporting suspended sediment across and eventually off the shelf. Moreover, bottom currents on the shelf are sometimes strong enough to erode unconsolidated silt and clay. Thus, the substrate serves as a source for BNL suspended matter. In addition, advected suspended matter contributes to the BNL.
Ph. D. in Philosophy Texas A & M University 1984
Includes bibliographical references (leaves 86-91).