Alicia F. Balster-Gee Katherine L. Maier Daniel S. Brothers Samuel Y. Johnson Patrick E. Hart Stephen R. Hartwell 2018 seismic-reflection data in SEG-Y format data release DOI:10.5066/F7T43SBK Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/F7T43SBK https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79 This data release contains approximately 190 line-kilometers of processed, high-resolution multichannel seismic-reflection (MCS) profiles that were collected aboard the R/V Snavely in 2015 on U.S. Geological Survey cruise 2015-617-FA in Monterey Bay, offshore central California. The majority of MCS profiles collected are oriented north-south across the Monterey Canyon head to address marine geohazards and submarine canyon evolution. The MCS profiles were acquired using a 700-Joule minisparker source and a 24-channel digital streamer. 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. Additional information about the field activities from which these data were derived is available online at: http://cmgds.marine.usgs.gov/fan_info.php?fan=2015-617-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20150223 20150306 ground condition at time data were collected Planned As needed -122.305 -121.82436523 36.9441115 36.63534156 USGS Metadata Identifier USGS:5a31b58be4b08e6a89d70d79 ISO 19115 Topic Category oceans geoscientificInformation Data Categories for Marine Planning Bathymetry and Elevation USGS Thesaurus sub-bottom profiling marine geophysics geospatial datasets Marine Realms Information Bank (MRIB) keywords seismic reflection profiling None U.S. Geological Survey USGS Coastal and Marine Geology Program CMGP Pacific Coastal and Marine Science Center PCMSC Geographic Names Information System (GNIS) Pacific Ocean State of California Monterey Bay Monterey Canyon NGA GEOnet Names Server (GNS) Monterey Canyon Monterey Fan None 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. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-460-4747 pcmsc_data@usgs.gov https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79?name=2015-617-FA_index_map.jpg&allowOpen=true index map JPEG SEG-Y Rev 1 Ray W. Sliter Samuel Y. Johnson Janet T. Watt Daniel S. Scheirer Parker Allwardt Peter J. Triezenberg 2013 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. https://pubs.usgs.gov/of/2013/1071/ Identified as best available version 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. 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. Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver. Depths shown in the seismic data files are in milliseconds (round trip travel time) and are referenced to sea level. 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. 20150306 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. 20151210 Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov 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 WGS 1984 UTM Zone 10N 0.9996 -123.0 0.0 500000.0 0.0 coordinate pair 0.0001 0.0001 Meter D WGS 1984 WGS 1984 6378137.0 298.257223563 Local surface 0.1 meters Attribute values Navigation and seismic shots with Time Stamp in standard SEG-Y file format Society of Exploration Geophysicists (SEG) Technical Standards, available for download at http://seg.org/Publications/SEG-Technical-Standards U.S. Geological Survey - ScienceBase mailing and physical

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov 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). 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. SEG-Y SEG-Y rev 1 Zip file contains the processed seismic data per navigation line Winzip, 7-zip, or Winrar are free software that will open .zip files 1280 https://www.sciencebase.gov/catalog/file/get/5a31b58be4b08e6a89d70d79 https://doi.org/10.5066/F7T43SBK Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data, metadata, and an image map showing the location of the seismic lines. The second link points to a landing page for the project. None. 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. 20201019 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-460-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998