Identification_Information: Citation: Citation_Information: Originator: Twichell, Dave Publication_Date: 1997 Title: GI Air Gun Data Archive - GYRE 97006 Publication_Information: Publication_Place: Woods Hole, MA Publisher: U.S. Geological Survey Other_Citation_Details: none Online_Linkage: none Description: Abstract: This CD-ROM contains digital high resolution seismic- reflection data collected during the USGS GYRE 97006 cruise. The coverage is the offshore Louisana continental slope, Gulf of Mexico. The seismic-reflection data are stored as IBM 4 bit interger SEG-Y format that can be read and manipulated by most seismic- processing software. Much of the information specific to the data are contained in the headers of the SEG-Y format files. The file system format is ISO 9660 which can be read with DOS, Unix, and MAC operating systems with the appropriate CD-ROM driver software installed. This directory contains the GI air gun data collected on the GYRE 97006 cruise. These data were collected using a Seismic Systems Inc. generated injected (GI) air gun source. On this cruise the GI gun was configured with two 105 cu. in. chambers, a total of 210 cu. in. The GI gun works by using one chamber for a primary pulse and the second chamber injects a pulse near the maximum expansion of the primary pulse. This results in a dampening effect on the collapse of the primary bubble pulse. The data were logged on an Intel based PC computer (Mudseis system). The data are two-channel (two traces per shot). Purpose: The seismic-reflection data are being archived so that further digital processing can be done for the seafloor mapping project: TECTONICS AND SEDIMENTARY PROCESSES OF THE SALT DEFORMED TEXAS- LOUISIANA CONTINENTAL SLOPE. This project proposes (1) mapping the surficial geology of a large part of the TX-LA slope using advanced processing techniques and existing GLORIA and multibeam data, (2) conducting a higher resolution sidescan and sampling cruise to refine the understanding of tectonic, sediment supply, and oceanographic controls on sedimentary processes, (3) linking the surficial geology with the subsurface structures and stratigraphy for modern and ancient comparison of sedimentary systems, and (4) integrating data into a three-dimensional model of depositional systems in this complex environment. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19970409 Beginning_Time: 045227 Ending_Date: 19970413 Ending_Time: 131459 Currentness_Reference: publication date Status: Progress: In work Maintenance_and_Update_Frequency: Unknown Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: - 92.833333 East_Bounding_Coordinate: - 91.916667 North_Bounding_Coordinate: 27.5 South_Bounding_Coordinate: 26.25 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: seismic reflection Theme_Keyword: Seismic Systems Inc. Theme_Keyword: GI Air Gun Theme_Keyword: SEG-Y Theme_Keyword: ISO 9660 CD- ROM Place: Place_Keyword_Thesaurus: None Place_Keyword: Gulf of Mexico Place_Keyword: Louisiana Place_Keyword: LA Place_Keyword: continental slope Place_Keyword: R/V GYRE Access_Constraints: for U.S. Geological Survey use only Use_Constraints: for U.S. Geological Survey use only Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Twichell, Dave Contact_Organization: U.S. Geological Survey Contact_Position: Seafloor Mapping Project Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Woods Hole Field Center 384 Woods Hole Road Quissett Campus City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: (508) 548-8700 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: dtwichell@usgs.gov Data_Set_Credit: D. Twichell, D. Nichols, T. O'Brien, B. Irwin, V. Cross, M. Taylor D. Foster, B. Danforth, S. Harrison, J. Brand, C. Spagnuolo Native_Data_Set_Environment: ISO 9660 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Quantitative_Attribute_Accuracy_Assessment: Attribute_Accuracy_Value: Attribute_Accuracy_Explanation: Logical_Consistency_Report: Completeness_Report: archive of SEG-Y format seismic data Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The ship was navigated with differential GPS The GI air gun was towed 10 m aft of the ship The two-channel streamer was towed 100 m aft of the ship. Each channel consisted of a 25 m length of streamer. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 5-10 meters Horizontal_Positional_Accuracy_Explanation: the ship position is accurate within 5-10 meters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The air gun was towed at depth of 1 meter. The streamer was towed at a depth of 5 meters. Vertical resolution of the seismic data is about 1-2 meters. There was no correction to a datum such as mean sea level. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 1-2 meters Vertical_Positional_Accuracy_Explanation: Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Gulf of Mexico, Louisiana Continental Slope Direct_Spatial_Reference_Method: raster Raster_Object_Information: Raster_Object_Type: Voxel Row_Count: > 10000 Column_Count: 1 Vertical_Count: 4096 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal_Transverse_Mercator: UTM_Zone_Number: 15 Transverse_Mercator: Scale_Factor_at_Central_Meridian: .9997 Longitude_of_Central_Meridian: -93 Latitude_of_Projection_Origin: 0 False_Easting: 0 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 5 Ordinate_Resolution: 5 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298257 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: assumed sea level Altitude_Resolution: 1 Altitude_Distance_Units: two-way travel time Altitude_Encoding_Method: Depth_System_Definition: Depth_Datum_Name: fish depth below sea level (local surface) Depth_Resolution: 1 Depth_Distance_Units: meters Depth_Encoding_Method: Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Entity_and_Attribute_Detail_Citation: Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Soderberg, Nancy Contact_Organization: U.S. Geological Survey Contact_Position: Data Library Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Woods Hole Field Center 384 Woods Hole Road Quissett Campus City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: (508) 548-8700 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: nsoderberg@usgs.gov Resource_Description: U.S. Geological Suvey Internal CD-ROM Data Archive Distribution_Liability: This Compact Disc-Read Only Memory (CD- ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ISO 9660 CD-ROM Format_Version_Number: ISO 9660 Format_Specification: Format_Information_Content: SEG-Y File_Decompression_Technique: none Transfer_Size: 650 MB Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Capacity: Recording_Density: 512 Recording_Density_Units: bytes Recording_Format: ISO 9660 Compatibility_Information: UNIX, DOS, MAC Fees: Metadata_Reference_Information: Metadata_Date: 19970408 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Nealon, Jeffrey W. Contact_Organization: U.S. Geological Survey Contact_Position: Geophysics Group Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Woods Hole Field Center 384 Woods Hole Road Quissett Campus City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: (508) 548-8700 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: jnealon@usgs.gov Metadata_Standard_Name: FGDC Content Standard Metadata_Standard_Version: 19940608 Metadata_Time_Convention: universal time Metadata_Access_Constraints: none Metadata_Use_Constraints: none