Metadata: Identification_Information: Citation: Citation_Information: Originator: Karynna Calderon Originator: Shawn V. Dadisman Originator: James G. Flocks Originator: Dana S. Wiese Publication_Date: 2003 Title: Archive of Boomer and Chirp Seismic Reflection Data Collected During USGS Cruise 01RCE02, Southern Louisiana, April and May 2001 Geospatial_Data_Presentation_Form: Seismic Reflection Profile Section Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: 2003-88 Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.3133/ofr2003088 Description: Abstract: This archive consists of two-dimensional marine seismic reflection profile data collected in the Mississippi River Delta, Atchafalaya River Delta, and Shell Island Pass in southern Louisiana. These data were acquired in April and May of 2001 aboard the R/V G. K. Gilbert. The data are available in a variety of formats, including binary, ASCII, HTML, shapefiles, and GIF and JPEG images. Binary data are in Society of Exploration Geophysicists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and GIF images of the profiles may be viewed with your web browser. The GIS information provided is compatible with ESRI's GIS software. For more information on the seismic surveys see http://walrus.wr.usgs.gov/infobank/g/g201la/html/g-2-01-la.meta.html These data are also available via GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean ( http://www.virtualocean.org/) earth science exploration and visualization applications. Purpose: Marine seismic reflection data are used to image and map sedimentary and structural features of the seafloor and subsurface. These data are useful in mapping stratigraphy and in assessing other submarine geologic characteristics and features. These data were collected as part of a larger USGS River Contaminant Evaluation (RCE) Project. Supplemental_Information: The USGS Center for Coastal and Watershed Studies team in St. Petersburg, FL, assigns a unique identifier to all seismic data collected during each cruise or field activity. The method used to assign the identifier for the activity is as follows: YYPRO##, where YY stands for the last 2 digits of the year in which the fieldwork is conducted; PRO is a 3-digit acronym for the project the data are collected for; and ## is a 2-digit event tag that represents a discreet leg or time period of fieldwork. Here, 01RCE02 tells us the data were collected in 2001 for the River Contaminant Evaluation Project and that the data were collected during the second field activity for that calendar year. The trackline naming convention the center uses for each seisimic line is as follows: yye###a, where yy is the last 2 digits of the year in which the data were collected; e is a 1-digit abbreviation for the equipment type (i.e. c for chirp and b for boomer); ### is a 3-digit number representing a specific track; and a is a 1-digit alphanumeric representing the section of a track if recording was prematurely terminated. Seismic reflection profiles are acquired by means of an acoustic source (usually generated electronically) and hydrophone or receiver arrays. Both elements are typically towed in the water behind a survey vessel. The sound source emits a short acoustic pulse that propagates through the water and sediment columns. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor) and detected at the receiver. This process is repeated at intervals ranging between 100 ms and 1 s depending on the source type. In this way, a two-dimensional image of the geologic structure beneath the ship track is constructed. Seismic data were stored in SEG-Y format, which is a standard digital format that can be read and manipulated by most seismic processing software packages. The SEG-Y file format includes a 3,200-byte descriptive header that contains detailed information regarding the data acquisition and processing parameters. All data presented here are stored in SEG-Y, integer, Motorola format. The SEG-Y formatted trace data files have a .TRA extension. Additional recording parameters for each seismic data file can also be found in the .PAR file associated with each .TRA file. However, the .PAR, UTM_401_1.pln, and cent_rmc.pln files are only needed to process or display the data with Triton Elics Delph Seismic software. The boomer energy source consists of capacitors that are charged to a high voltage and then discharged through a transducer in the water. The frequency range of the source is between 300 and 3000 Hz. The transducer was towed on a sled at the sea surface providing 100 joules per shot. The reflected energy was received by an Innovative Technologies, Inc. (ITI) ST-5 solid core streamer and recorded by PC-based Triton Elics Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced over 6 m. Only data received by elements 3, 4, 5, and 6 were summed. The streamer was positioned parallel to the boomer sled and laterally separated from it by about 7 m. The sled was towed about 20 m behind the GPS antenna. The sample frequency of the data was 12 kHz, and the total record length was 100 ms. The fire rate was every 0.5 s, which resulted in a shot spacing of about 1 m based on survey speeds of 3.5 - 4 knots. The chirp data use a signal of continuously varying frequency. The seismic source employed for the chirp data consisted of an EdgeTech X-Star SP424 tow fish running Triton Elics FSSB software. The tow fish was routinely flown 2 - 5 m above the seafloor. Therefore, water depths shown on the chirp profiles are relative to the depth of the tow fish and not to sea level. Furthermore, the raising or lowering of the tow fish during a survey to avoid obstacles or follow relief produces a relative shift in the multiple reflections seen in the profile, which may be confused as a geologic feature. Any elevation change of the tow fish is recorded in the crew logbook. The fish was towed about 10 m behind the GPS antenna, and no correction for this offset has been made. The sample frequency of the data was 25 kHz. Tracklines 01c001 - 01c009 were shot every 0.25 s to a record length of 50 ms, and tracklines 01c010 - 01c011b were shot every 0.125 s to a record length of 33 ms. Based on survey speeds of 3.5 - 4 knots, the shot spacing for the fire rate of 0.25 s was about 0.5 m, and the shot spacing for the fire rate of 0.125 s was about 0.25 m. For each recorded shot of the chirp data, 3 channels of trace data were collected. Channel 3 is the "real," or in-phase component of the signal, channel 2 is the "imaginary," or quadrative component of the signal, and channel 1 is the "envelope," or product of channels 2 and 3. Only channel 1 was used to produce the profiles presented here. However, all channels are included in the SEG-Y data files. The original trackline 01c011 was divided into 01c011a and 01c011b because the number of traces exceeded the maximum allowed by the processing system. GPS navigation was provided to the acquisition system every second by a Trimble-Centurian P-Code receiver. The accuracy of this receiver is to within 100 m. However, the data required some editing to remove spurious data values. The edited results were used to generate the trackline maps presented here. In addition, we have converted the latitude and longitude coordinates to UTM coordinates for UTM Zone 15. The navigation data have not been corrected to reflect the offset between the source and the GPS antenna. Position fixes for every 500 shots and for the start of line are also provided as an aid for registering of the data after plotting. Because boomer and chirp data are collected at different frequencies, position fixes for each system are provided. All navigation files are stored as flat ASCII text files. The trackline maps provided in this archive are in geographic projection. They were created using ESRI's GIS software ArcView 3.2, exported to Adobe Illustrator for further editing, and saved for the web in JPEG format. These JPEG images are viewable with your WWW browser. Included on this disc are the ArcView projects and associated shapefiles used to create the trackline maps presented here. The projects were created with ArcView 3.2 and are compatible with ArcView 3.x (Unix or Windows) and ArcGIS 8.x (Windows). The shapefiles can also be viewed using the public domain software ArcExplorer 2.0 (Windows) and 4.0 (Windows, Unix, Linux), which can be downloaded from the ESRI website at . Field Activity Collection System (FACS) logs are available in both HTML and Rich Text format (.rtf). Scanned GIF images of the original FACS logbooks and crew logbooks are also provided. Also included on this DVD are Seismic Unix (SU) scripts that allow the user to strip off navigation fixes from the SEG-Y headers, along with a fix for every 500 shots (boomer data) or every 1,000 shots (chirp data), and produce a filtered (boomer data only) and gained, and a GIF image of each profile. These images can then be displayed using a variety of shareware programs such as ImageMagick (Unix or Linux) or a web browser. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20010426 Ending_Date: 20010503 Currentness_Reference: Data collection interval Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -91.445162 East_Bounding_Coordinate: -89.072237 North_Bounding_Coordinate: 29.509807 South_Bounding_Coordinate: 28.966402 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:c38ebeed-7c44-484e-9af7-518fa4f15039 Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: marine seismic reflection Theme_Keyword: boomer Theme_Keyword: chirp Theme_Keyword: 01RCE02 Theme_Keyword: SEG-Y Theme_Keyword: River Contaminant Evaluation Project Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: distributions Theme_Keyword: substrate Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) Keywords Theme_Keyword: seismic reflection Theme_Keyword: marine geophysics Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: seismic reflection methods Theme_Keyword: sub-bottom profiling Theme_Keyword: marine geophysics Place: Place_Keyword_Thesaurus: None Place_Keyword: Louisiana Place_Keyword: Mississippi River Delta Place_Keyword: South Pass Place_Keyword: Pass-A-Loutre Place_Keyword: Garden Bay Place_Keyword: Atchafalaya River Delta Place_Keyword: Atchafalaya Bay Place_Keyword: Shell Island Pass Access_Constraints: None. These data are held in the public domain. Use_Constraints: The U.S. Geological Survey requests to be acknowledged as the originator of the data in future products or derivative research. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: James G. Flocks Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: 600 Fourth Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 803-8747, ext. 3012 Contact_Electronic_Mail_Address: jflocks@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/basemap.jpg Browse_Graphic_File_Description: Trackline map of all boomer data collected during USGS Cruise 01RCE02. These data were collected in Louisiana river deltas in April and May of 2001. This map is in geographic projection and was created at a scale of 1:1,200,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/mapa.jpg Browse_Graphic_File_Description: Trackline map of boomer data collected in the Mississippi River Delta (lines 01b001 - 01b010--refer to area A of the full survey area map) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:150,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/mapb.jpg Browse_Graphic_File_Description: Trackline map of boomer data collected in the Atchafalaya River Delta and Shell Island Pass (lines 01b011 - 01b015--refer to area B of the full survey area map) during USGS Cruise 01RCE02 in May of 2001. This map is in geographic projection and was created at a scale of 1:86,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/mapa1.jpg Browse_Graphic_File_Description: Trackline map of boomer data collected in South Pass of the Mississippi River Delta (parts of lines 01b001 and 01b002--refer to area A1 of Boomer Map A) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:25,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/mapa2.jpg Browse_Graphic_File_Description: Trackline map of boomer data collected in South Pass of the Mississippi River Delta (parts of lines 01b003 and 01b007--refer to area A2 of Boomer Map A) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:25,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/BOOMER/mapa3.jpg Browse_Graphic_File_Description: Trackline map of boomer data collected in Pass-A-Loutre of the Mississippi River Delta (parts of lines 01b006 and 01b008 - 01b010--refer to area A3 of Boomer Map A) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:25,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/basemap.jpg Browse_Graphic_File_Description: Trackline map of all chirp data collected during USGS Cruise 01RCE02. These data were collected in Louisiana river deltas in April and May of 2001. This map is in geographic projection and was created at a scale of 1:1,200,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/mapa.jpg Browse_Graphic_File_Description: Trackline map of chirp data collected in the Mississippi River Delta (lines 01c001 - 01c006--refer to area A of the full survey area map) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:150,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/mapb.jpg Browse_Graphic_File_Description: Trackline map of chirp data collected in the Atchafalaya River Delta and Shell Island Pass (lines 01c007 - 01c011b--refer to area B of the full survey area map) during USGS Cruise 01RCE02 in May of 2001. This map is in geographic projection and was created at a scale of 1:86,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/mapa1.jpg Browse_Graphic_File_Description: Trackline map of chirp data collected in Pass-A-Loutre of the Mississippi River Delta (parts of lines 01c002 and 01c004 - 01c006--refer to area A1 of Chirp Map A) during USGS Cruise 01RCE02 in April of 2001. This map is in geographic projection and was created at a scale of 1:25,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The waterbodies layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/mapb1.jpg Browse_Graphic_File_Description: Trackline map of chirp data collected in Shell Island Pass (parts of lines 01c011a and 01c011b --refer to area B1 of Chirp Map B) during USGS Cruise 01RCE02 in May of 2001. This map is in geographic projection and was created at a scale of 1:32,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://cmgds.marine.usgs.gov/images/browse/01RCE02/CHIRP/mapb2.jpg Browse_Graphic_File_Description: Trackline map of chirp data collected in the Atchafalaya River Delta (parts of lines 01c010 and 01c011b--refer to area B2 of Chirp Map B) during USGS Cruise 01RCE02 in May of 2001. This map is in geographic projection and was created at a scale of 1:32,000 using ESRI's GIS software ArcView 3.2. The image was exported to Adobe Illustrator for further editing and saved for the web in JPEG format. The USGS is not the originator of all layers used in creating this map. The rivers layer is a LOSCO (Louisiana Oil Spill Coordinator's Office) dataset derived from ESRI/GDT (Geographic Data Technology, Inc.) data that were in turn derived from Bureau of the Census TIGER/Line files. The waterbodies layer is also a LOSCO dataset derived from ESRI/GDT data. Browse_Graphic_File_Type: JPEG Data_Set_Credit: We thank Gina M. Peery and Greg Berman of the USGS in St. Petersburg, FL, for their field support during data collection. Boat captains Dave Bennett of Eckerd College in St. Petersburg, FL, and Keith Ludwig of the USGS in St. Petersburg, FL, also assisted in data collection. We also thank reviewers Peter W. Swarzenski and Jack L. Kindinger of the USGS in St. Petersburg, FL, whose comments improved this document. Native_Data_Set_Environment: SEG-Y -------------------------------------------------------------------------------- Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The validity or accuracy of marine seismic reflection profiles is highly qualitative and depends on equipment and operating condition variables. Visual inspection of the images rendered from the data did not show any major anomalies. The original trackline 01c011 was divided into 01c011a and 01c011b because the number of traces exceeded the maximum allowed by the processing system. Logical_Consistency_Report: These datasets are from one cruise with consistent instrument calibrations. Completeness_Report: These data are collected along tracklines (2D). Therefore, data are inherently incomplete. Geologic details between lines must be inferred. All boomer tracklines were recorded to 100 ms. Chirp tracklines 01c001 - 01c009 were recorded to 50 ms, and lines 01c010 - 01c011b were recorded to 33 ms. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The positional accuracy was determined with a Trimble-Centurian P-Code receiver. The accuracy of this receiver is to within 100 m. For boomer line 01b001, the GPS data were fed to a navigation computer running Hypack software, which converted the data to UTMs. The UTM string was then fed to the Delph Seismic acquisition software and recorded in the SEG-Y headers for each trace. For all other lines, the GPS string was fed directly to the Delph Seismic acquisition system, and navigation fixes were recorded in latitude and longitude in the SEG-Y headers. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Boomer data are relative to sea level. Chirp data depth is relative to the depth of the tow fish. Lineage: Process_Step: Process_Description: Boomer processing: Raw SEG-Y data were processed with Seismic Unix to produce the GIF-formatted seismic profiles included in this report. A representative data processing sequence consisted of: 1)Bandpass filter: 300-500-2500-3000 Hz 2)Automatic gain control 3)Postscript display 4)Convert Postscript to GIF format Process_Date: 2002 Process_Step: Process_Description: Chirp processing: Raw SEG-Y data were processed with Seismic Unix to produce the GIF-formatted seismic profiles included in this report. A representative data processing sequence consisted of: 1)Stripped off channel 1 for each shot 2)Automatic gain control 3)Postscript display 4)Convert Postscript to GIF format Process_Date: 2002 Process_Step: Process_Description: Positional (navigation) data: As the seismic reflection data were acquired, the position of the vessel was continuously determined by a GPS receiver. Positions were recorded approximately every second and written to the SEG-Y header. The ASCII navigation and the 500-shot interval navigation files were extracted from the SEG-Y headers using Seismic Unix scripts. Process_Date: 2002 Process_Step: Process_Description: Editing navigation: The ASCII navigation files were extracted from the SEG-Y headers and edited to remove spurious data points. The data were then processed using PROJ.4 freeware to convert latitude and longitude coordinates to UTMs (Zone 15). The data were also reformatted for use with ESRI's GIS software ArcView 3.2. Process_Date: 2002 Process_Step: Process_Description: Open-File preparation: No processing has been done to the SEG-Y data files provided on this DVD. The data were displayed as 8-bit gray scale Postscript files using the Seismic Unix 'psimage' algorithm. The Postscript images were then converted to GIF images with ImageMagick. Process_Date: 2002 Process_Step: Process_Description: Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Process_Date: 20170124 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Alan O. Allwardt Contact_Position: Contractor -- Information Specialist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7551 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aallwardt@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20201013 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Horizontal X and Y locations (both UTMs and latitude and longitude) for each shot location are provided in ASCII position files, along with the time the shot was recorded in Greenwich Mean Time. -------------------------------------------------------------------------------- Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0000027 Longitude_Resolution: 0.0000027 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: WGS84 Ellipsoid_Name: WGS84 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Binary data file: Each profile is available as a binary file in Society of Exploration Geophysicists (SEG) SEG-Y format. A SEG-Y file consists of 1) a 3,200-byte file identification record of ASCII-formatted general information, 2) a 400-byte binary record with information such as sample rate and record length specific to the dataset, and 3) multiple records, with one seismic reflection trace per record for the boomer data and three for the chirp data. Each trace record is preceded by a 240-byte trace header containing information such as trace number and acquisition day and time specific to each trace. The trace data are represented as a time series of unitless 16-bit integer or 32-bit real numbers proportional to the reflection coefficient. The SEG-Y file is useful only if you have access to specialized software designed to process and display seismic reflection data. These SEG-Y files have a .TRA extension and range in size from 12.1 to 286.7 MB. Entity_and_Attribute_Overview: Graphic image file: Each profile is available as a GIF image. The trackline maps provided are JPEG images that contain hotlinks to the seismic profile GIF images. The profiles range in size from 1.8 to 11.3 MB. -------------------------------------------------------------------------------- Entity_and_Attribute_Detail_Citation: Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, n.2, p. 344-352. Also available online at: . Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Shawn V. Dadisman Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: 600 Fourth Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 803-8747, ext. 3029 Contact_Electronic_Mail_Address: sdadisman@usgs.gov Contact_Instructions: Data may be available on-line only by special arrangement with the distributor above. Resource_Description: U.S. Geological Survey Open-File Report 03-88 DVD Distribution_Liability: This Digital Versatile Disc (DVD) 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 for the accuracy, completeness, or usefulness of any 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 DVD 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: SEG-Y Format_Information_Content: The SEG-Y standard format (Barry et al., 1975) consists of the following: a 3,600-byte reel identification header with the first 3,200 bytes consisting of an ASCII header block and a 400-byte binary header block that both include information specific to line and reel number, a trace data block that follows the reel identification header with the first 240 bytes of each trace block consisting of the binary trace identification header, and seismic data samples that follow the trace identification header. File_Decompression_Technique: None Transfer_Size: 2470 Digital_Transfer_Option: Offline_Option: Offline_Media: DVD Recording_Format: ISO 9660 Compatibility_Information: UNIX, LINUX, DOS, MAC Digital_Form: Digital_Transfer_Information: Format_Name: ESRI project, shapefile, metadata Format_Information_Content: GIS projects and layers used to create the boomer trackline maps presented in this archive and associated metadata. File_Decompression_Technique: unzip Transfer_Size: 20.4 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://pubs.usgs.gov/of/2003/of03-088/SOFTWARE/ARC/BOOMER.ZIP Digital_Form: Digital_Transfer_Information: Format_Name: ESRI project, shapefile, metadata Format_Information_Content: GIS projects and layers used to create the chirp trackline maps presented in this archive and associated metadata. File_Decompression_Technique: unzip Transfer_Size: 20.1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://pubs.usgs.gov/of/2003/of03-088/SOFTWARE/ARC/CHIRP.ZIP Digital_Form: Digital_Transfer_Information: Format_Name: SEGY data download Format_Information_Content: The SEG-Y standard format (Barry et al., 1975) consists of the following: a 3,600-byte reel identification header with the first 3,200 bytes consisting of an ASCII header block and a 400-byte binary header block that both include information specific to line and reel number, a trace data block that follows the reel identification header with the first 240 bytes of each trace block consisting of the binary trace identification header, and seismic data samples that follow the trace identification header. File_Decompression_Technique: none Transfer_Size: 2.470 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://cmgds.marine.usgs.gov/data/01rce02/boomer/ Network_Resource_Name: https://cmgds.marine.usgs.gov/data/01rce02/chirp/ Fees: Available from USGS Information Services. Prices vary. Ordering_Instructions: Most open-file reports are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone: 1-888-ASK-USGS; email: infoservices@usgs.gov). Technical_Prerequisites: Use of SEG-Y data requires specialized seismic processing software, such as Unix or Linux based public domain software Seismic Unix (SU) developed by the Colorado School of Mines Center for Wave Phenomena, which can be downloaded at . -------------------------------------------------------------------------------- Metadata_Reference_Information: Metadata_Date: 20201013 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Karynna Calderon Contact_Organization: U.S. Geological Survey Contact_Position: Geographer, Data Management Group Contact_Address: Address_Type: mailing address Address: 600 Fourth Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 803-8747, ext. 3143 Contact_Electronic_Mail_Address: kcalderon@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 --------------------------------------------------------------------------------