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This map covers the region -78.00 to -74.50 longitude and 36.50 to 39.80 latitude. Note that the underwater topography has been exaggerated by a factor of 5 relative to the land topography. This was done to better show bottom features.
The Chesapeake Bay is the large estuary extending from the top center of the image nearly to the bottom center. It is the sunken valley of the Susquehanna River which flows into it at the northern end and is visible as a gray trace cutting diagonally through the rough green topography of the Piedmont Plateau. The southeastern edge of the Piedmont Plateau is fairly sharp along the northwestern part of the Chesapeake Bay. This sharp edge is where the plateau drops down to the coastal plain is known as the Fall Line since many rivers and streams have falls or rapids along this line. To the west of the Peidmont Plateau are a series of somewhat disconnected low areas known as Triassic Lowlands. Just west of the low areas is a band of mountains (Camp David is on one of these mountains near the top of the image). West of the mountains is the Great Valley (Cumberland Valley) which occupies the upper left corner of this image.
The Chesapeake Bay itself shows several deeper channels, these were the inner river valleys before the drainage basin became flooded. The waters of the Chesapeake come from as far away as New York state. The upper Chesapeake gets most of it's water from central Pennsylvania, with somewhat less from rivers draining the Piedmont Plateau.
The large, rather flat peninsula is the Delmarva Peninsula since the three states Delaware, Maryland, and Virginia share it. Delaware Bay is on the northeastern side of the Delmarva Peninsula. The Delaware River flows into Delaware Bay from the north. Several artifacts in the available bathymetry data appear in Delaware Bay.
The right side of this image is dominated by the gently downward sloping continentel shelf. The shelf ends at the continental slope, part of which shows up at the lower right corner of this image.
Ray Sterner sterner@tesla.jhuapl.edu The Johns Hopkins University North latitude 39.16 degrees. Applied Physics Laboratory West longitude 76.90 degrees. Laurel, MD 20723-6099 WWW Home page: http://fermi.jhuapl.edu/res