Measurements of natural hydrocarbon gas flux in the Coal Oil Point seep field (COP1710, EK80)
On 26 October 2017, acoustic data was collected in tandem with direct, in situ gas
flux measurements. Acoustic data was collected using a Simrad ES200-7C split-beam
echosounder that was interfaced with an EK80 Wideband Transceiver. The echosounder
was operated over a frequency bandwidth of 160-260 kHz. Direct measurements of gas
flux were obtained using a bubble catch device (BCD) that was designed to capture
gas in an inverted graduated cylinder through a funnel. An underwater camera that
was attached to the BCD was used to capture images of the accumulation of gas within
the cylinder. The echosounder was pole-mounted to the port side of the R/V Connell,
while the BCD was hand deployed from the starboard side of the vessel. A Garmin WAAS-enabled
GPS system was interfaced with the EK80 software to provide position of the vessel
throughout the survey.
Collection of both acoustic data and direct gas flux measurements were obtained at three seep sites located within the Coal Oil Point seep field: Platform Holly, Seep Tent and La Goleta. Data collection was obtained by positioning the vessel in locations of high seepage activity (verified with the acoustic data) and then allowing the vessel to drift over the area until no seepage activity was observed. Both the acoustic data and the direct gas flux measurements were collected simultaneously throughout the survey. The BCD was deployed at a depth of 23 m at La Goleta and Seep Tent and at 15 m at Platform Holly. A total of 20 .MP4 files were obtained with the BCD.
A preliminary test run of the BCD was conducted at the La Goleta seep site at 1532 UTC. Following the BCD test, both acoustic data and video images from the BCD were acquired at the La Goleta seep site. At approximately 1930 UTC, data collection at La Goleta was completed and the R/V Connell transited to the Seep Tent seep site. Data collection at Seep Tent commenced at approximately 1956 UTC and was completed at 2116 UTC. A CTD cast was performed after the survey near Seep Tent. A field calibration was done for the ES200-7C split-beam echosounder following the CTD cast with a 28.5 mm Tungsten-Carbide calibration spheres. At 2150 UTC, the R/V Connell arrived at Platform Holly in order to collect both acoustic and BCD measurements. Data collection with the BCD finished at 2244 UTC and a final acoustic survey in the vicinity of Platform Holly was conducted between 2256 UTC and 2357 UTC.
Collection of both acoustic data and direct gas flux measurements were obtained at three seep sites located within the Coal Oil Point seep field: Platform Holly, Seep Tent and La Goleta. Data collection was obtained by positioning the vessel in locations of high seepage activity (verified with the acoustic data) and then allowing the vessel to drift over the area until no seepage activity was observed. Both the acoustic data and the direct gas flux measurements were collected simultaneously throughout the survey. The BCD was deployed at a depth of 23 m at La Goleta and Seep Tent and at 15 m at Platform Holly. A total of 20 .MP4 files were obtained with the BCD.
A preliminary test run of the BCD was conducted at the La Goleta seep site at 1532 UTC. Following the BCD test, both acoustic data and video images from the BCD were acquired at the La Goleta seep site. At approximately 1930 UTC, data collection at La Goleta was completed and the R/V Connell transited to the Seep Tent seep site. Data collection at Seep Tent commenced at approximately 1956 UTC and was completed at 2116 UTC. A CTD cast was performed after the survey near Seep Tent. A field calibration was done for the ES200-7C split-beam echosounder following the CTD cast with a 28.5 mm Tungsten-Carbide calibration spheres. At 2150 UTC, the R/V Connell arrived at Platform Holly in order to collect both acoustic and BCD measurements. Data collection with the BCD finished at 2244 UTC and a final acoustic survey in the vicinity of Platform Holly was conducted between 2256 UTC and 2357 UTC.
- Cite as: Alexandra Padilla, Scott Loranger, Frank Kinnaman, David Valentine, Tom Weber (2019): Water Column Sonar Data Collection (COP1710, EK80). National Centers for Environmental Information, NOAA. doi:10.25921/1q3m-3689 [access date].
- COP1710_EK80
- doi:10.25921/1q3m-3689
gov.noaa.ngdc.mgg.wcd:COP1710_EK80
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Ordering Instructions | Contact the NCEI Water Column Sonar Data Manager to order data |
Distributor | Water Column Sonar Data Manager NOAA National Centers for Environmental Information (303) 497-4742 wcd.info@noaa.gov |
Dataset Principal Investigator | Alexandra Padilla Graduate Student UNH/CCOM apadilla@ccom.unh.edu |
Dataset Principal Investigator | Scott Loranger UNH/CCOM sloranger@ccom.unh.edu |
Dataset Principal Investigator | Frank Kinnaman UCSB frank_kinnaman@ucsb.edu |
Dataset Principal Investigator | Dave Valentine Professor University of Califonria, Santa Barbara 805-893-2973 valentine@geol.ucsb.edu |
Dataset Principal Investigator | Tom Weber Assistant Professor UNH/CCOM-JHC 603-862-1659 weber@ccom.unh.edu |
Time Period | 2017-10-26T15:30:01 to 2017-10-26T23:59:34 |
Spatial Reference System | urn:ogc:def:crs:EPSG:4326 |
Spatial Bounding Box Coordinates |
West:-119.90934
East:-119.8525
South:34.37295
North:34.39187
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Dataset Progress Status | Complete - production of the data has been completed |
Data Update Frequency | Not planned |
Purpose | The cruise was conducted to obtain estimates of gas flux in the region using both acoustic and direct capture methods. |
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Theme keywords | Global Change Master Directory (GCMD) Science Keywords
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Data Center keywords | Global Change Master Directory (GCMD) Data Center Keywords
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Instrument keywords | Global Change Master Directory (GCMD) Instrument Keywords
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Place keywords | International Hydrographic Organization (IHO) Sea Area ("Limits of Oceans and Seas"
publication S-23)
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Lineage Statement | EK80 raw data files collected at the La Goleta seep site are named incorrectly as "Patch_bubblecatch-D..." and "Patch_acousticline-D...". The times presented in the filenames for both thte EK80 data and video files from the BCD are reported in UTC. |
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Last Modified: 2019-02-19
For questions about the information on this page, please email:wcd.info@noaa.gov