Name/Title
S02.07.026Description
The fathometer recorder used by the Lake Erie Section of the Ohio Geological Survey. A fathometer is a depth finder that uses sound waves to determine the depth of water. The Benmar unit pictured here was permanently attached inside the Research Vessel GS-1. It shows the profile of the lakebed on the strip chart trace. With experience, a geologist can also determine the type of sediment from the trace. The image was taken on September 17, 1970. The location given is approximate to the research vessel docked at the Battery Park Marina in Sandusky, Erie County, Ohio.
The Lake Erie Section also had a Raytheon fathometer for using near shore in the smaller runabout boats. The Raytheon unit was smaller and portable for monitoring the more shallow depths near shore.
Information about the history of the Ohio Geological Survey’s Lake Erie Group Section is available in Lake Erie Geology Office Closes by Don Guy, Dale Liebenthal, and Michael C. Hansen (Ohio Geological Survey, Ohio Geology Newsletter, No. 1, 2008) pages 6 and 7.
This slide image included in the USGS National Digital Catalog for NGGDPP Grant G15AP00115 in FY2015.Context
Machine attached to the side of blue boat; it has a screen and knobs on it. Battery Park Marina in Sandusky, Ohio.