C. Patrick Ervin | Search USGS

USGS2004

Principal facts for gravity data collected in Wisconsin: A web site and CD-ROM for distribution of data

Principal facts for 40,488 gravity stations covering the entire state of Wisconsin are presented here in digital form. This is a compilation of previously published data collected between 1948 and 1992 from numerous sources, along with over 10,000 new gravity stations collected by the USGS since 1999. Also included are 550 gravity stations from previously unpublished sources. Observed gravity and complete-Bouguer gravity anomaly data for this statewide compilation are included here. Altogether, 14 individual surveys are presented here.

Wisconsin↗

USGS1990

1986 Great Lakes Seismic refraction survey (GLIMPCE): Line A - refraction mode

In the fall of 1986, the Geological Survey of Canada (GSC), the United States Geological Survey (USGS), two Canadian universities -- University of Western Ontario and University of Saskatchewan, and four American universities -- Northern Illinois University, Southern Illinois University, University of Wisconsin-Madison and University of Wisconsin-Oshkosh participated in a major deep seismic experiment in Lake Superior under the GLIMPCE (Great Lakes International Multidisciplinary Program on Crustal Evolution) umbrella. This Open-File Report presents the seismic sections for line A, which was shot specifically for refraction recording. The main target for study by this line was the Mid-Continent Rift System. All recording stations, 31 in total (26 land stations and 5 OBSs), recorded energy from shots fired every two minutes (333 m spacing) by a tuned airgun array towed by a contracted ship along line A in Lake Superior. These data are the densest such data ever recorded in the continental North America over such distances. It is also unique since coincident seismic reflection and refraction are available.

Lake Superior↗