LOWFILCLIP: ESRI Binary 75-m Grid of the Lowstand Surface in Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (UTM, Zone 16, WGS84)

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: David C. Twichell
Originator: VeeAnn A. Cross
Publication_Date: 2012
Title:
LOWFILCLIP: ESRI Binary 75-m Grid of the Lowstand Surface in Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (UTM, Zone 16, WGS84)
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2012-1003
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/of/2012/1003/data/grids/lowstand.zip>
Online_Linkage: <http://pubs.usgs.gov/of/2012/1003/html/catalog.html>
Larger_Work_Citation:
Citation_Information:
Originator: V.A. Cross
Originator: D.C. Twichell
Originator: D.S. Foster
Originator: T.F. O'Brien
Publication_Date: 2012
Title:
Apalachicola Bay Interpreted Seismic Horizons and Updated IRIS Chirp Seismic-Reflection Data
Edition: 1
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2012-1003
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/of/2012/1003/>
Description:
Abstract:
Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the combined product of modern estuarine conditions and the late Holocene evolution of the bay. A suite of geophysical data and cores were collected during a cooperative study by the U.S. Geological Survey, the National Oceanic and Atmospheric Administration Coastal Services Center, and the Apalachicola National Estuarine Research Reserve to refine the geology of the bay floor as well as the bay's Holocene stratigraphy. Sidescan-sonar imagery, bathymetry, high-resolution seismic profiles, and cores show that oyster reefs occupy the crests of sandy shoals that range from 1 to 7 kilometers in length, while most of the remainder of the bay floor is covered by mud. The sandy shoals are the surficial expression of broader sand deposits associated with deltas that advanced southward into the bay between 6,400 and 4,400 years before present. The seismic and core data indicate that the extent of oyster reefs was greatest between 2,400 and 1,200 years before present and has decreased since then due to the continued input of mud to the bay by the Apalachicola River. The association of oyster reefs with the middle to late Holocene sandy delta deposits indicates that the present distribution of oyster beds is controlled in part by the geologic evolution of the estuary. For more information on the surveys involved in this project, see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2005-001-FA> and <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2006-001-FA>.
Purpose:
This grid represents the interpretation of the lowstand surface based on seismic-reflection profiles collected in 2006 in Apalachicola Bay. This surface is an irregular erosional surface that was cut primarily by rivers during Pleistocene lowstands of sea level.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20060531
Ending_Date: 20060627
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -85.049997
East_Bounding_Coordinate: -84.875864
North_Bounding_Coordinate: 29.722211
South_Bounding_Coordinate: 29.611336
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: Woods Hole Coastal and Marine Science Center
Theme_Keyword: WHCMSC
Theme_Keyword: Field Activity Serial Number 06001
Theme_Keyword: Field Activity 2006-001-FA
Theme_Keyword: Info Bank ID R-1-06-GM
Theme_Keyword: interpreted horizon
Theme_Keyword: seismic-reflection
Theme_Keyword: seismic interpretation
Theme_Keyword: ESRI grid
Theme_Keyword: R/V Rafael
Theme_Keyword: ASV ISIS
Theme_Keyword: Autonomous Surface Vessel
Theme_Keyword: Independently (or) Remotely Influenced Surveyor
Theme_Keyword: Chirp seismics
Theme_Keyword: EdgeTech FSSB 424
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: oceans
Theme_Keyword: oceans and estuaries
Theme_Keyword: oceans and coastal
Theme_Keyword: geoscientificInformation
Theme_Keyword: location
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Apalachicola Bay
Place_Keyword: Florida
Place_Keyword: Apalachicola National Estuarine Research Reserve
Place_Keyword: Gulf of Mexico
Place_Keyword: United States
Place_Keyword: St. Vincent Island
Place_Keyword: Little St. George Island
Place_Keyword: St. George Island
Place_Keyword: North America
Access_Constraints: None.
Use_Constraints:
The public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.4000
Cross_Reference:
Citation_Information:
Originator: D.C. Twichell
Originator: B.D. Andrews
Originator: H.L. Edmiston
Originator: W.R. Stevenson
Publication_Date: 2007
Title:
Geophysical mapping of oyster habitats in a shallow estuary; Apalachicola Bay, Florida
Edition: 1
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2006-1381
Publication_Information:
Publication_Place: Woods Hole Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/of/2006/1381/>
Cross_Reference:
Citation_Information:
Originator: D.C. Twichell
Originator: E.A. Pendleton
Originator: R.Z. Poore
Originator: L.E. Osterman
Originator: K.W. Kelso
Publication_Date: 2009
Title:
Vibracore, radiocarbon, microfossil, and grain-size data from Apalachicola Bay, Florida
Edition: 1
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2009-1031
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/of/2009/1031/>
Cross_Reference:
Citation_Information:
Originator: E. Bergeron
Originator: C.R. Worley
Originator: T.F. O'Brien
Publication_Date: 2007
Title:
Progress in the development of shallow-water mapping systems: using an autonomous surface vehicle for shallow-water geophysical studies
Series_Information:
Series_Name: Sea Technology
Issue_Identification: v. 48, no. 6, p. 10-15
Publication_Information:
Publication_Place: Arlington, VA
Publisher: Compass Publications, Inc.

Data_Quality_Information:
Completeness_Report:
All useable seismic-reflection profiles collected in 2006 within Apalachicola Bay were used in the interpretation.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The R/V Rafael acquired data recording navigation using a Real Time Kinematic (RTK) GPS at a one second interval. The GPS antenna was mounted over the bathymetric sonar. The seismic pole mount system was on the starboard side and approximately 1.5 meters aft of the bathymetry system. No offset was added to the navigation for the seismic data. For seismic data collected with the IRIS system, an RTK GPS system was also used. The GPS antenna for IRIS was mounted directly over the seismic transducer. This system can provide positions to within 0.1 meters. However, due to some errors with the acquisition software, this accuracy is reduced. The accuracy is approximately 2 m given the constraints of the acquisition system.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
For the Rafael seismic system, the transducers were located approximately 1 meter below the water surface. This offset was not adjusted for. For the IRIS system, the transducers are barely below the water surface, less than half a meter. This depth is not adjusted for. Although the seismic data were not tide corrected, the depth surfaces are related to a sea-floor surface based largely on swath bathymetry data that was tide corrected to mean lower low water.
Lineage:
Source_Information:
Source_Contribution:
The seismic data used for the interpretation come from two different seismic systems. The bulk of the data are from the EdgeTech FSSB 424 system pole mounted on the R/V Rafael. These data were logged in SEG-Y format using SBLogger. This system had a 1/4 second fire rate. The remainder of the data, in the shallower areas, were acquired with the USGS IRIS system. IRIS is a remotely operated vehicle that has an EdgeTtech FSSB 424 chirp sub-bottom profiling system mounted to it. The seismic data were recorded by JSTAR, a software package developed by EdgeTech. This system had a much faster fire rate, almost 15 times per second. The EdgeTech FSSB 424 is a chirp sub-bottom profiler that operates within a 4-24kHz frequency range. The IRIS vehicle is navigated using Real-Time Kinematic (RTK) GPS. The antenna is mounted directly on the platform to minimize navigational error. The R/V Rafael was also navigated with an RTK GPS system with the navigation antenna approximately 1.5 meters forward of the seismic transducer. This offset was not accounted for.
Process_Step:
Process_Description:
Two different seismic systems acquired data in Apalachicola Bay in 2006. One system was the EdgeTech FSSB 424 (4-24kHz) aboard the R/V Rafael. These data were acquired as SEG-Y files using SBLogger. The second seismic system was also an EdgeTech FSSB 424 chirp system mounted on the USGS autonomous vehicle IRIS. These data were acquired with JSTAR in JSF format and converted to SEG-Y format using a C-program written by Tom O'Brien (USGS, Woods Hole). These SEG-Y files were then converted from IEEE format to IBM floating point using SIOSEIS, and the shots were renumbered starting at one. With initial preparation work on the seismic data complete, these data and navigation needed to be loaded into Landmark SeisWorks software for interpretation. In order to load the seismic data and navigation into Landmark SeisWorks software the navigation needed to be extracted from the header of the seismic data. An AWK script was used to extract the navigation from the seismic data headers and export in UTM, Zone 16 eastings and northings, rounded to the nearest meter.
Process_Date: 2006
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Contact_Voice_Telephone: 508-548-8700
Contact_Facsimile_Telephone: 508-457-2310
Process_Step:
Process_Description:
Once the navigation is extracted from the seismic data, this navigation has to be loaded into the interpretation software. In this case, that's Landmark SeisWorks version R2003. The navigation is loaded using Data - Management - Seismic Data Manager. A new survey is created (06001 for the Rafael data, asv06 for the IRIS data). Then, Data - Import - Seismic Data Loader and point to the navigation text file. When loading the navigation, use a decimation of 0, use first shot point if duplicates are found, and overwrite data in target project if necessary. A decimation of zero was used because the IRIS navigation had already been decimated to take every 5th record from the complete navigation extracted from the headers of the IRIS seismics. The Rafael data did not need decimation. The Rafael data had a 1/4 second fire rate while the IRIS data fired at approximately 15 shots per second. Once the navigation is loaded and verified, then the actual seismic data can be loaded. To do this, use PostStack Data Loader. There was a small issue in working with seismic data in SeisWorks where it's better to have all the seismic profiles at the same sample rate. It's a display issue in the interpretation phase where opening a profile in a window with a different sample rate than the previously loaded profile doesn't always refresh the window properly. The result is an incorrect interpretation - the interpreted line falls in the wrong spot vertically. The seismic data were resampled to the same sample rate to eliminate this problem. The Rafael acquired data used two different sample rates: 40 microseconds and 80 microseconds. The Rafael seismics were all resampled to 40 microseconds in the PostStack data loader. Additionally, the lines had an automatic 8-bit scaling applied to each profile. The IRIS seismic lines were acquired with two sample rates - 23 microseconds and 46 microseconds. All of the lines were resampled to a 40 microsecond sampling interval in PostStack data loader and had an automatic 8-bit scaling applied to each profile. With the seismic data now loaded, the project has to be modified so these changes are reflected in the surveys and the data can be interpreted.
Process_Date: 2007
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
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
Process_Step:
Process_Description:
The lowstand horizon was created in SeisWorks, and the lowstand surface was digitized from each seismic reflection profile where present. The surface is identified on seismic profiles as an irregular reflector that separates the underlying acoustically massive material from overlying acoustic units characterized by parallel, continuous closely spaced reflectors.
Process_Date: 2008
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: David C. Twichell
Contact_Organization: U.S. Geological Survey
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2266
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: dtwichell@usgs.gov
Process_Step:
Process_Description:
Once the interpretation is complete, the horizon is exported as a text file with the line name, easting, northing, and the depth to the horizon in milliseconds (two-way travel time). This process step and all subsequent process steps were overseen by the same person - VeeAnn A. Cross.
Process_Date: 2008
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
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
Process_Step:
Process_Description:
A header line is added to the exported text file, and converted from a tab-delimited file to a comma-delimited file.
Process_Date: 2008
Process_Step:
Process_Description:
ArcMap 9.2 was used to load this text file as an event theme using Tools - Add XY data. The projection is defined on input as UTM, Zone 16, WGS84.
Process_Date: 2008
Process_Step:
Process_Description:
This event theme is converted to a shapefile by right mouse click - Data - Export Data and generating the output shapefile low021508csv.shp. This shapefile represents the depth to the lowstand horizon in milliseconds (two-way travel time). Any points falling outside Apalachicola Bay were deleted. The attribute mtrs_1800 was added and field calculator was used to convert the depth in milliseconds to depth in meters using 1800 meters per second and changing the sign so that more negative indicates deeper. This value does not take into account the difference of the speed of sound in water vs sediment. To account for a speed of sound difference in the water column and the sediment, this shapefile was joined with seafloor.shp and the output put to join_sf2low2.shp. The attribute ms_minus was added to this shapefile. Because of small gaps in interpreting the various surfaces, the records where the distance between joined values is less than 5 meters were selected. The joined seafloor ms are negatives, with the lowstand travel times positive, so ms_minus = ms (lowstand) + ms_2 (from seafloor) which yields the travel time in the sediment. Then the records selection was switched (large distances reflecting points joined more than 5 meters away) and the ms_minus was set to -9999.
Process_Date: 2008
Process_Step:
Process_Description:
The isopach travel times where the lowstand surface exists were converted to meters in ArcMap 9.2 by using the attribute calculator and converting the travel time to meters using a speed of sound of 1800 meters per second. VAC Extras 2.02 gridspot tool was used to extract the sea floor depth in meters from the sea floor grid (topo2r_sf) and place in the attribute sf_grd. The grid was used instead of the interpreted sea floor values because the grid is primarily composed of the swath bathymetry values and using the interpolated grid will maintain surface relationships. A new attribute was added to the shapefile "low4grd" and the field calculator was used such that low4grd = sf_grd - lowiso_m. The sea floor grid values are negative while the lowiso_m are positive, therefore this calculation will give the total depth.
Process_Date: 2008
Process_Step:
Process_Description:
The lowstand surface is an erosion surface that should follow drainage rules. Topo2Raster is a good gridding technique for these types of datasets. Additionally, the drainage enforcement is enhanced when stream thalwegs are included in the gridding process. These thalwegs can be inferred by studying the data points and creating a shapefile to reflect these locations. This information can then be supplied to the gridding algorithm. Using ArcMap 9.2 - ArcToolbox - Spatial Analyst Tools - Interpolation - Topo to Raster. Input features: joinsf2low2.shp attribute low4grd data type PointElevation. The boundary file was lowstand_outline_3.shp. lowstandthal_sm3 was used as a stream input. The output grid is t2r_lowall with a cell size of 75 meters. Smallest Z value was set to -50 in order to omit the -9999 values. Drainage enforcement was set to ENFORCE and the primary type of input data was set to spot.
Process_Date: 2008
Process_Step:
Process_Description:
Using ArcMap 9.2 a filter was applied to the resulting grid. ArcToolbox - Spatial analyst tools - neighborhood - filter. The filter type was low pass, with the option to ignore NODATA in calculations. The output was lowall_filter. Because of extrapolation, there are a couple of places where the lowstand sticks above the ravinement (flooding) surface. To fix this use raster calculator: con([lowall_filter] <= [ravsurfall], [lowall_filter]). The effect of this calculation is to use the lowstand value where that value is less than or equal to the ravinement (flooding) surface. If the lowstand surface is greater than the ravinement (flooding) surface, set the value to the ravinement surface. Doing this maintains the proper surface relationships. The output is lowfilclip.
Process_Date: 2008

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 160
Column_Count: 222
Vertical_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 16
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -87.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 75.000000
Ordinate_Resolution: 75.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS_1984
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257224
Vertical_Coordinate_System_Definition:
Depth_System_Definition:
Depth_Datum_Name: Mean lower low water
Depth_Resolution: 0.1
Depth_Distance_Units: meters
Depth_Encoding_Method: Implicit coordinate

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Depth values are recorded as negatives with more negative values indicating deeper water.

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
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
Resource_Description: Downloadable Data
Distribution_Liability:
Neither the U.S. government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: WinZip
Format_Version_Number: 9.0
Format_Information_Content:
The WinZip contains the ESRI binary grid (both the grid folder and the info folder) as well as the associated metadata.
Transfer_Size: 0.189
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://pubs.usgs.gov/of/2012/1003/data/grids/lowstand.zip>
Network_Resource_Name: <http://pubs.usgs.gov/of/2012/1003/html/catalog.html>
Fees: none
Technical_Prerequisites:
These data are available as a 32-bit floating point raster in Environmental Systems Research Institute (ESRI) format. To utilize these data, the user must have software capable of viewing or importing an ESRI raster.

Metadata_Reference_Information:
Metadata_Date: 20120412
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
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
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.9.6 on Wed Apr 18 17:07:54 2012