Time-series photographs of the sea floor in western Massachusetts Bay: June 1998 to May 1999

This report presents time-series photographs of the sea floor obtained from an instrumented tripod deployed at Site A in western Massachusetts Bay (42° 22.6' N., 70? 47.0' W., 30 m water depth, figure 1) from June 1998 through May 1999. Site A is approximately 1 km south of an ocean outfall that began discharging treated sewage effluent from the Boston metropolitan area into Massachusetts Bay in September 2000. Time-series photographs and oceanographic observations were initiated at Site A in December 1989 and are anticipated to continue to September 2005. This one of a series of reports that present these images in digital form. The objective of these reports is to enable easy and rapid viewing of the photographs and to provide a medium-resolution digital archive. The images, obtained every 4 hours, are presented as a movie (in .avi format, which may be viewed using an image viewer such as QuickTime or Windows Media Player) and as individual images (.tif format). The images provide time-series observations of changes of the sea floor and near-bottom water properties.

The photographs obtained at Site A are part of a long-term study to understand the transport and long-term fate of sediments and associated contaminants in the Massachusetts bays. (See the Web site Boston Sewage Outfall: The Fate of Sediments and Contaminants in Massachusetts Bay, http://woodshole.er.usgs.gov/project-pages/bostonharbor/.) This long-term study is carried out by the U.S. Geological Survey (USGS) in partnership with the Massachusetts Water Resources Authority (MWRA)(http://www.mwra.state.ma.us/) and the U.S. Coast Guard (USCG) (http://www.uscg.mil). Long-term oceanographic observations at Site A were obtained to document seasonal and inter-annual changes in currents, hydrography, and suspended-matter concentration, and the importance of infrequent catastrophic events, such as major storms or hurricanes, in sediment resuspension and transport. (See Butman and others (2002) for a description of the oceanographic measurements at Site A and Butman and Bothner (1997) for discussion of sediment transport in Massachusetts Bay.)