Chesapeake Bay Surficial Sediment Distribution
The sediment distribution map was derived from the following publication:
The Surficial Sediments of the Chesapeak Bay, Maryland:
Physical Characteristics and Sediment Budget,
Randall T. Kerhin, Patricia J.Blakeslee, Nicholas
Zoltan and Robert Cuthbertson, 1988, 82 p., 8 pls.
37 figs., 28 tabs., Report of Investigation 48,
Maryland Geological Survey.
and the
Chesapeak Bay surficial sediment database. The above publication may be
purchased from our Publications
Office. The database
and metadata are available for download from our FTP site. The metadata
file contains a detailed description of the methodolgy used in the collection,
analysis and interpretation of data used to produce this map.
An explanation of Shepard's Classification and Diagram can be found on the
Shepard's Diagram web page.
A companion map of Baltimore Harbor Surficial
Sediments is now on-line. This is an interactive map that displays data for selected locations within the harbor.
Map Creation
The Sediment Distribution Map was created in Autodesk's
AutoCAD MAP 3.
Conversion to the DWF file format for use on the World Wide Web was done using AutoCAD's
Internet Utilities.
The Chesapeake Bay shoreline was digitized from
U.S. Geological Survey
digital orthophoto quadrangles. Because the original shoreline map was 5.5 megabytes (in
AutoCAD DWG file format), we simplified the shoreline for use on the Web. While this
process presents a less detailed map, download times are greatly reduced by using smaller
file sizes. By using the DWF format, the entire sediment distribution map was reduced from
6.8 megabytes to 137 kilobytes. The
WHIP! plugin for Netscape Navigator and Internet Explorer allows the user to quickly
download, and interact with, vector-based images in the DWF format.
Web Presentation
The Chesapeake Bay Sediment Distribution Map and Web pages were created by
Bob Conkwright at MGS.
Lamere Hennessee wrote the text, brief metadata and
full metadata files. Coastal and Estuarine program chief
Jeff Halka instigated this project and should
take the heat for the content of these pages