Name/Title
S21.05.012Description
The COCORP vibrator truck caravan moving west to east across Coshocton County, Ohio. Shown here are the Vibroseis trucks that served as the source of the ground vibrations. The trucks are more or less identical, with each one vibrating in sync with the others. Multiple trucks were used to increase the energy injected into the ground. One recording truck was used elsewhere to record the signals after they returned to the surface. The photograph was taken by Michael C. Hansen in October 1987. The location is approximate to an area in southern Coshocton County where the seismic line was produced.
In the autumn of 1987, the Consortium for Continental Reflection Profiling (COCORP), based at Cornell University in Ithaca, New York, conducted a National Science Foundation funded seismic-reflection profile across Ohio. Five 22-ton vibrator trucks owned by Seismograph Services of Tulsa, Oklahoma, sent vibrations to depths of 25 miles or more into the ground. The reflected seismic data profile is used as the primary data source for investigation of the deep crustal structure beneath the United States. The two seismic lines in Ohio were the result of a proposal that the Ohio Division of Geological Survey submitted to COCORP to investigate a north-south oriented zone in western Ohio that appears to be a major area of discontinuity in Precambrian basement rock. Seismic reflection profiling, as carried out by COCORP, uses truck-generated vibrations as a source of energy to probe deep into the earth's crust. These vibrations bounce off boundaries, known as reflectors, representing changes in rock types or major structural features and return to the surface, where they are picked up by sensitive recording devices called geophones. The data are recorded and stored on computer tapes and then processed to produce a vertical cross section of the area traversed. The cross section displays the reflectors encountered by the seismic waves.
REVIEW
Date Estimate Source: Story in Columbus Dispatch places the truck caravan in Delaware and Knox Counties during the first week of October, see: "Shaken Bedrock May Offer Clues to Ohio's Depths" by David Lore (Dispatch Science Reporter), Home Final Edition, Section News 3D, 11 October 1987.
Location Estimate Source: "Structure Contour Map on the Precambrian Unconformity Surface in Ohio and Related Basement Features" by Mark T. Baranoski (Ohio Geological Survey, Columbus 2013) Digital Map Series PG-23.
For more information, see: COCORP Traverse Across Ohio by Michael C. Hansen (Ohio Geological Survey, Ohio Geology Newsletter, Fall 1987) page 1+. AND "How the World Was Made"--The COCORP Traverse of Ohio by Michael C. Hansen (Ohio Geological Survey, Ohio Geology Newsletter, Winter 1989) page 1+.
For more information, see: Cornell University's Institute for the Study of the Continents (INSTOC) Consortium for Continental Reflection Profiling (COCORP) website at <a href="http://www.geo.cornell.edu/geology/cocorp/COCORP.html" rel="noreferrer nofollow">www.geo.cornell.edu/geology/cocorp/COCORP.html</a>
From Dr. Larry D. Brown of Cornell University's Institute for the Study of the Continents in an e-mail to Lisa Long on July 13, 2016:
Lisa's Question: S21.05.012 shows 5 vehicles in the caravan. I assume each vehicle did some part of the activity, but I don’t know how the process was done. Are five instrument trucks required and do you know what each of them is needed to do?
Dr. Brown's Answer: These are the Vibroseis trucks that served as the source of the ground vibrations that we recorded after they travelled downward to be reflected back to the surface from subsurface layers. The trucks are more or less identical, with each one vibrating in sync with the others. Multiple trucks were used to increase the energy injected into the ground. One recording truck was used (elsewhere) to record the signals after they returned to the surface.
This slide image included in the USGS National Digital Catalog for NGGDPP Grant G15AP00115 in FY2015.Context
Five trucks coming up gravel road. Vibrator truck caravan in Coshocton County, Ohio.