Field map of line of soundings offshore from Cape Henlopen, Delaware Bay. In the far SE corner, the break in soundings from 85 fathoms to 145 fathoms is one of the earliest indications of the continental shelf break.

Image ID: cgs05060, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: Delaware, Offshore
Photo Date: 1847 ca.
Credit: NARA C&GS Colllection

Category: Coast and Geodetic Survey/Archive Seafloor Mapping/

• High Resolution Photo Available