Identification_Information:

Citation:

Citation_Information:

Originator: Gina M. Peery

Originator: Barbara Lidz

Originator: Dana S. Wiese

Publication_Date: 2002

Title: Archive of Boomer Seismic Reflection Data

Collected on USGS Cruise 97KEY01,

Upper and Middle Florida Keys,

12 October - 1 November, 1997.

Geospatial_Data_Presentation_Form: Seismic Reflection Profile Section

Series_Information:

Series_Name: U.S. Geological Survey Open-File Report

Issue_Identification: 02-421

Publication_Information:

Publication_Place: St. Petersburg, FL

Publisher: U.S. Geological Survey

Description:

Abstract:

This report consists of two-dimensional marine seismic reflection profile

data from the upper and middle Florida Keys. The area of operations

extended from just north of Molasses Reef off north Key Largo

(Upper Keys) to the east boundary of Looe Key National Marine Sanctuary

(Lower Keys). These data were acquired in October and November of 1997

with the Charter Vessel Captain's Lady. The data are available in a variety

of formats, including binary, ASCII, HTML, Shapefiles, JPG and GIF 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 JPG images of the profiles may be viewed with your WWW browser.

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 the extent and thickness of shallow sedimentary units in the

upper and middle Florida Key, and in assessing other submarine geologic

characteristics and features. The main objective of this cruise was to

fill a major gap in the seismic data record. Data had not been collected for

this area at any time during a 20-year study of the reef track.

Supplemental_Information:

Seismic reflection profiles are acquired by means of an acoustic source

(usually generated electronically), and a hydrophone or hydrophone array.

Both elements are typically towed in the water behind a survey vessel.

The sound source emits a short acoustic pulse, which 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 hydrophone. This process is repeated at

intervals ranging between 100 ms and 1s depending on the source type. In

this way a two-dimensional image of the geologic structure beneath the

ship track is constructed.

Seismic data are 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 3200-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 files and the

plg_gga.pln file are only needed to replay the data with Triton Elics Delph

Seismic software.

The seismic source employed here consisted of a boomer transducer towed

on a sled at the sea surface providing 100 joules per shot. The reflected

energy was received by an Innovative Transducer Inc. (ITI) solid core

streamer and recorded by PC-based Triton-Elics Delph Seismic acquisition

software. The ITI streamer contains 10 hydrophones evenly spaced over 6

meters however only data received by elements 5-8 where summed, resulting

in a higher signal to noise ratio for the data. The streamer was positioned

parallel to the boomer sled and laterally separated from it by 7 m.

The sled was towed 20 m behind the GPS antennae. The sample frequency

of the data was 12000 Hz and the total record length was 100 ms. The

fire rate was every 0.25 sec, which resulted in a shot spacing of about

0.5 m based on survey speeds of 3.5-4 knots.

P-Code GPS navigation was fed to the acquisition system every

second by a Rockwell navigation receiver. The accuracy of this receiver

is within 100 m. However, the data required some editing. A filter was

designed to remove spurious data values and these edited results can be

used to generate trackline maps at any scale or projection desired,

however the shotpoint data has not been corrected to reflect the 20 m

offset between the source and the GPS antenna. Also the raw navigation

files did not have year or julian day written to the headers. This information

was handwritten into the edited and shotpoint navigation files. Position fixes

for every 500th shotpoint and the start and end of line are also provided as

an aide for easy registering of the data after projection. The trackline maps

provided in this report are geographic projections and were created using

ESRI's GIS software ArcView 3.2 and exported to Adobe Illustrator for

further editing, then saved as GIF images. These GIF images are viewable

with your WWW browser. All navigation files are stored as flat ASCII text

files.

Included on this disc are GIS files created with ESRI’s Arcview 3.2,

displaying the shotpoint information for each seismic trackline. These

files are compatible with either ArcView 3.x (UNIX or WINDOWS) or

ArcGIS 8.1 (WINDOWS). The files can also be viewed using the Windows

compatible public domain software ArcExplorer 2.0, and 4.0. To download

a free copy of ArcExplorer go to the ESRI website

(http://www.esri.com/software/arcexplorer/).

Field Activity Collection System (FACS) logs are available in both html

and Rich Text format, along with the scanned GIF images of the original

logbooks.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19971012

Ending_Date: 19971101

Currentness_Reference:

Data assumed to be constant over time but may

change due to geologic processes.

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None Planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -80.29

East_Bounding_Coordinate: -81.39

North_Bounding_Coordinate: 25.15

South_Bounding_Coordinate: 24.40

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: marine seismic reflection

Theme_Keyword: boomer

Theme_Keyword: 97KEY01

Theme_Keyword: UDF DVD

Theme_Keyword: SEG-Y

Place:

Place_Keyword_Thesaurus: none

Place_Keyword: Florida Keys

Place_Keyword: Key Largo

Place_Keyword: Molasses Reef

Place_Keyword: Looe Key National Marine Sanctuary

Place_Keyword: Key Biscayne

Place_Keyword: Biscayne Bay

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: Barbara Lidz

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 X3031

Contact_Electronic_Mail_Address: blidz@usgs.gov

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/fullarea.gif

Browse_Graphic_File_Description:

A full survey map of the tracklines collected during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaA.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area A during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaB.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area B during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaC.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area C during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaD.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area D during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaE.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area E during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: DVD/MAPS/areaF.gif

Browse_Graphic_File_Description:

A survey map of the tracklines collected in Area F during

USGS Cruise 97KEY01, in October and November, 1997,

along the upper and middle Florida Keys. This map is a

geographic projection. It was created using ESRI’s GIS

software ArcView 3.2, then exported to Adobe Illustrator

for further editing, and saved for the web as a GIF image.

Data_Set_Credit:

The USGS Coastal and Marine Geology Program (CMGP)

provided the funding for research east and northeast of the

Looe Key National Marine Sanctuary (LKNMS), to Molasses

Reef off the upper Keys. Billy Causey, Superintendent of the

Florida Keys National Marine Sanctuary (FKNMS), and

Sanctuary Rangers (Florida Department of Natural Resources,

Bureau of Environmental Land Management) are thanked for

their cooperation during the field survey. Personnel from the

USGS in St. Petersburg, Fla., and the National Oceanic and

Atmospheric Administration’s (NOAA) FKNMS conducted

most of the project in the middle and upper Keys as a

cooperative study under permit FKNMS-29-97. We thank

Captain Stephen R. Cawthon who led Captain's Lady on her

final voyage as a research vessel in 1997, for assistance in data

collection. Appreciation is extended to numerous colleagues for

their field assistance. All are acknowledged by name in publications

resulting from each part of the project. Stanley D. Locker, University

of South Florida St. Petersburg campus, assisted in numerical data

conversion to compensate for the rapid speed-of-sound return in

shallow water. James G. Flocks, USGS geologist, produced the

seismic-profile trackline navigation and data map panels for

contouring. Digital cartographer Lance E. Thornton digitized final

contours into the ARC/INFO GIS program for the bedrock and

isopach plates. Jeff Dismukes provided scripts for editing and

reformatting the navigation data for use with ESRI’s ArcView 3.2.

The authors greatly appreciate the efforts of these colleagues.

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. After visual inspection of the JPG images

provided in this report these notes must be made about the data.

Important Notes:

1.Seismic Profiles key9717b, key9717c, key9717d, key9718a,

key9718b, key9723a and key9728a contain deep water delays

ranging from 10 ms to 40 ms.

2.Also small 0.5 ms to 2 ms static shifts are seen in all profiles.

These shifts vary for each profile and last for short irregular

periods of time.

3.Only 70 ms of data was collected for trackline key9717c; all

other lines were collected with 100 ms of data saved.

4.Trackline key9716t contains no usable data; it was a test line.

Logical_Consistency_Report: This data set is from a single cruise with

consistant instrument calibrations.

Completeness_Report:

These data are collected along tracklines (2D).

Therefore, data are inherently incomplete. Geologic details between

lines must be inferred. All tracklines were recorded to 100ms.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

The position accuracy was determined with the Rockwell

PLGR P-code GPS receiver fed to the acquistion software,

FUGAWI V2.08. The accuracy of this receiver is within

100 m.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The vertical position was local sea level and there have been no

corrections to a vertical datum or for tidal variations.

Lineage:

Process_Step:

Process_Description: Boomer processing:

Raw SEG-Y data was processed with SU and (Triton Elics

Software) to produce the JPG 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 at 25ms/in and 300shots/in for all tracklines.

4)Convert Postscripts to GIF format, then to JPG format.

Process_Date: 2001

Process_Step:

Process_Description: Positional (navigation) data:

As the seismic reflection data were acquired, the position of the

vessel was continuously determined with the P-Code Global

Positioning System (GPS). Positions were recorded approximately

every second, and written to the SEG-Y header. The ASCII 500

shotpoint navigation files were extracted from the SEG-Y headers

using SU scripts.

Process_Date: 2001

Process_Step:

Process_Description: Editing navigation:

The raw navigation files were extracted from Delph

Seismic V2.10, and then run through a filter to edit out the

spurious fixes. The filtered data was also reformatted for

use with ESRI's GIS software ArcView 3.2. The edited

navigation files also had year and Julian day manually entered

to each file.

Process_Date: 2001

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

Aladdin Ghostscript. Then converted to JPG with Image Magick.

Only the JPG images are presented here.

Process_Date: 2001

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference:

Horizontal X and Y locations (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 (GMT).

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.000278

Longitude_Resolution: 0.000278

Geographic_Coordinate_Units: decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: WGS 84

Ellipsoid_Name: WGS 1984

Semi-major_Axis: 6378137 m

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-Y format. A SEG-Y file consists of 1) a 3200-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 data set; and 3) multiple records,

one seismic reflection trace per record. 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. These .tra files range in

size from the smallest being 14 MB to the largest being 142 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:

<http://www.seg.org/publications/tech-stand/index_body.html>

Entity_and_Attribute_Overview:

Graphic image file:

Each profile is available as a GIF or JPG image. The trackline maps

provided are GIF images that contain hot-links to the seismic profile

JPG images. The profiles range in size from 1.1 MB to 8.9 MB.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Rob Wertz

Contact_Organization: U.S. Geological Survey

Contact_Position: Manager - 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 X3045

Contact_Electronic_Mail_Address: rwertz@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 02-XXX 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 bythe 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 and others, 1975) consists of

the following: a 3600-byte reel identification header with the

first 3200 bytes consisting of an ASCII header block and a

400-byte binary header block. Both headers include information

specific to line and reel number. The trace data block follows

the reel identification header. The first 240 bytes of each trace

block is the binary trace identification header. The seismic data

samples follow the trace identification header.

File_Decompression_Technique: none

Transfer_Size:

Digital_Transfer_Option:

Offline_Option:

Offline_Media: DVD

Recording_Format: UDF (Universal Disc Format)

Compatibility_Information: UNIX, LINUX, DOS, MAC

Fees: available from the Denver Open-File Sales department, prices vary.

Ordering_Instructions: Most open-file reports are available from USGS

Information Services, Box 25286, Federal Center, Denver, CO 80225

(telephone: 303-202-4210; 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

from <http://www.cwp.mines.edu/cwpcodes> free of charge.

Metadata_Reference_Information:

Metadata_Date: 20010410

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Gina M. Peery

Contact_Organization: U.S. Geological Survey

Contact_Position: Geologist - 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 X3120

Contact_Electronic_Mail_Address: gpeery@usgs.gov

Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Formal Seismic Metadata