Multichannel minisparker seismic-reflection data of field activity 2015-617-FA; Monterey Bay, offshore central California from 2015-02-23 to 2015-03-06

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Balster-Gee, Alicia F., Maier, Katherine L., Brothers, Daniel S., Johnson, Samuel Y., Hart, Patrick E., and Hartwell, Stephen R., 2018, Multichannel minisparker seismic-reflection data of field activity 2015-617-FA; Monterey Bay, offshore central California from 2015-02-23 to 2015-03-06: data release DOI:10.5066/F7T43SBK, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/F7T43SBK
   • https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.305
   East_Bounding_Coordinate: -121.82436523
   North_Bounding_Coordinate: 36.9441115
   South_Bounding_Coordinate: 36.63534156
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79?name=2015-617-FA_index_map.jpg&allowOpen=true (JPEG)

   index map

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 23-Feb-2015

   Ending_Date: 06-Mar-2015

   Currentness_Reference:

   ground condition at time data were collected

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: seismic-reflection data in SEG-Y format
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      

      Indirect_Spatial_Reference:

      Horizontal X and Y locations for the seismic profile locations are provided and stored in the SEG-Y data trace headers in header bytes 81 and 85 locations

   2. What coordinate system is used to represent geographic features?
      The map projection used is WGS 1984 UTM Zone 10N.
      

      Projection parameters:

      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in Meter
      The horizontal datum used is D WGS 1984.
      The ellipsoid used is WGS 1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      

      Vertical_Coordinate_System_Definition:

      Depth_System_Definition:

      Depth_Datum_Name: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   Navigation and seismic shots with Time Stamp in standard SEG-Y file format

   Entity_and_Attribute_Detail_Citation:

   Society of Exploration Geophysicists (SEG) Technical Standards, available for download at http://seg.org/Publications/SEG-Technical-Standards

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Alicia F. Balster-Gee
   • Katherine L. Maier
   • Daniel S. Brothers
   • Samuel Y. Johnson
   • Patrick E. Hart
   • Stephen R. Hartwell
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

The U.S. Geological Survey (USGS) collected high-resolution multichannel seismic-reflection (MCS) profiles in 2015 across Monterey Bay, offshore central California. The goals of the MCS survey were to provide higher-resolution imaging of a buried paleochannel complex recently identified below the continental shelf adjacent to Monterey Canyon head and to complete a grid of subbottom data with existing single-channel seismic reflection profiles across Monterey Bay (Sliter and others, 2013). This cruise was funded by the USGS Coastal and Marine Geology Program and provided an extended shakedown test of a new multichannel streamer.

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 06-Mar-2015 (process 1 of 3)

   The multichannel seismic-reflection profiles were acquired with a 700-Joule minisparker source towed at 2 meters depth below the sea surface and fired at 1.2 to 1.4 seconds, depending on water depth. Data were recorded at 1.1 and 1.3 seconds and 0.25 milisecond sample interval in SEGD format using a 24-channel digital streamer with 3.125 receiver group spacing, 100m total length including lead-in section, towed at 2 meters below the sea surface. Survey speeds were approximately 4.5 knots.

   Date: 10-Dec-2015 (process 2 of 3)

   Seismic-reflection data were processed using Echos by Paradigm Geophysical. The following processing steps were applied to each line: bad traces killed, water column mute applied, full trace AGC applied, normal moveout correction (constant 1450 m/s velocity), swell static correction, stack, 80-600 post-stack bandpass filer, 80-600 butterworth filter, three trace mean post-stack runmix filter, time migration, and correct navigation was written to header bytes 81 and 85 in UTM coordinates.

   Date: 19-Oct-2020 (process 3 of 3)

   Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Road

   Woods Hole, MA
   

   508-548-8700 x2251 (voice)

   508-457-2310 (FAX)

   vatnipp@usgs.gov

3. What similar or related data should the user be aware of?
   Sliter, Ray W., Johnson, Samuel Y., Watt, Janet T., Scheirer, Daniel S., Allwardt, Parker, and Triezenberg, Peter J., 2013, High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur.

   Online Links:

   • https://pubs.usgs.gov/of/2013/1071/

   Other_Citation_Details:

   Sliter, R. Johnson, S.Y., Watt, J.T., Scheirer, D.S., Allwardt, P. and Triezenberg, P.J., 2013, High-resolution seismic-reflection and marine-magnetic data from offshore central California—San Gregorio to Point Sur: U.S. Geological Survey Open-File Report 2013–1071.

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   Identified as best available version
2. How accurate are the geographic locations?
   Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver.
3. How accurate are the heights or depths?
   Depths shown in the seismic data files are in milliseconds (round trip travel time) and are referenced to sea level.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Subbottom data were collected during USGS cruise 2015-617-FA using a 24-channel Geometrics GeoEel digital hydrophone streamer and a 700-Joule minisparker source. Quality control was conducted during the collection process.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:

USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator of the dataset and in products derived from these data. This information is not intended for navigation purposes.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? 2015-617-FA_mcs_data.zip contains high-resolution seismic-reflection (SEG-Y) data collected during PCMSC field activity 2015-617-FA. These data are divided up and presented by navigation line, as reflected in the individual file names. Equipment malfunction resulted in some lines having multiple parts (e.g 05 and 05T, 07A 07B and 07C).
3. What legal disclaimers am I supposed to read?

   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Zip file contains the processed seismic data per navigation line in format SEG-Y (version SEG-Y rev 1) Size: 1280
     Network links:	https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79 https://doi.org/10.5066/F7T43SBK

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?

   Use of SEG-Y data requires specialized software, such as ProMax and Seisworks by Landmark Geophysical; FOCUS and SeisX by Paradigm Geophysical; SPW by Parallel Geoscience; VISTA by Seismic Image Software; SeiSee by Dalmorneftegeophysica (DMNG); amongst others.

Who wrote the metadata?

Dates:

Last modified: 19-Oct-2020

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-460-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)