U.S. Geological Survey 2003 tabular digital data Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped depression tilted toward the main fault on the east side of the lake. The U.S. Geological Survey, in cooperation with researchers from several universities, has been studying the sediments of Bear Lake since 1996. The general purpose of this effort is to reconstruct past limnological conditions and regional climate on a range of timescales, from hundreds of years to hundreds of thousands of years. This research relates to a variety of human concerns, including water usage in the Bear River basin. Past work has included several coring operations, a seismic-reflection survey, sediment-trap deployments, a barge-mounted drilling operation with the GLAD800 drill rig, and a variety of other studies. The objectives of the September, 2002 operations, preliminarily reported here, were (1) to compile a detailed bathymetric map of the lake using swath-mapping techniques, in order to provide baseline data for a variety of applications and studies, and (2) to complete a sidescan-sonar survey of the lake, providing a nearly complete acoustic image of the lake floor. Limited amounts of subbottom acoustic-reflection data (CHIRP) were also collected, along with samples of lake-floor sediments representative of different kinds of backscatter patterns. These surveys followed an earlier subbottom acoustic-reflection survey (1997), using boomer and 3.5 kHz systems (S. M. Colman, unpublished data). Sediment samples were collected in order to ground-truth the sidescan-sonar data. Differing backscatter regimes were selected to sample in order to map their surficial sediment character. 20020915 20020916 Ground Condition Complete none planned -111.5 -111.17 42.2 41.08 none Sediment grab sample U.S. Geological Survey USGS Coastal and Marine Geology Program CMGP Woods Hole Field Center none Bear Lake Utah Idaho North America United States None. The USGS asks to be referenced in any use of these data. U.S. Geological Survey Jane F. Denny Geologist, Seafloor Mapping Group mailing and physical address

384 Woods Hole Road

Woods Hole MA 012543 USA 508-457-2311 508-457-2310 jdenny@usgs.gov Monday-Friday, 8am-5pm, Eastern Standard Time Positions are accurate within +/- 3 meters (recorded WAAS horizontal accuracy). These data were all acquired with a Van Veen Grab Sample off of the same platform. These data were collected within two days. These data are known to be complete. WAAS is assumed to be accurate within 1-2 meters. Standard GPS is assumed accurate within 5-10 meters. All data were recorded using the WAAS (Wide Area Augmentation System) navigation. All WAAS data are referenced to WGS84 datum. All sample locations are assumed to be accurate to +/- 3 meters. The samples were acquired with a Van Veen grab sampler. The position of each location was recorded using Coastal Oceanographics, Inc HYPACK Max. Latitude and Longitude values were converted to eastings and northings using USGS Mapgen PROJ command (UTM Zone 12, WGS84 Ellipsoid). The location file, listing longitude, latitude, eastings, northings, water depth at sample location, time, date and sample id, was then formated as an ArcView table. The table was imported into ArcView. A shapefile was generated from the table. 2003 Jane F. Denny U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 USA 508-457-2311 508-457-2310 jdenny@usgs.gov Vector point 0.000089992 0.000089992 Decimal degrees WGS84 WGS84 6378137.0000000 298.26 sample.shp Arcview shapefile ESRI Shape Feature geometry. ESRI point feature geometry name Arcview Longitude x coordinate of feature ESRI -111.5 -111.17 decimal degrees Latitude location of y coordinate ESRI 42.2 41 decimal degrees Easting location of X coordinate in UTM space ESRI 450000 490000 meters Northing location of Y coordinate in UTM space ESRI 4500000 4700000 meters Depth Water depth at sample location Fathometer 5 meters 65 meters Time Time the sample was collected USGS time Date Date sample was collected Calendar Date Date Sample Sample Identification USGS Sample ID USGS Jane F. Denny U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 USA 508-457-2311 508-457-2310 jdenny@usgs.gov JPG Images of Grab Samples Altough this data set and its lineage have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or it's related materials. The act of distribution shall not constitute any such warranty, and no resposibility is assumed by the USGS in the use of these data or related items. Users must assume resposibility for the proper use of this data. This data should not be used at resolutions for which it is not intended. This data has no been reviewed for conformity with U.S. Geological Survey editorial standards, or the North American Strigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government. 20030425 2003 Jane F. Denny U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 USA 508-457-2311 508-457-2310 jdenny@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 None None