Monterey Bay SVP data from cruise S-07-09-MB and S-10-09-MB

Title: Monterey Bay SVP data from cruise S-07-09-MB and S-10-09-MB

Abstract:

USGS Western Coastal & Marine Geology scientists mapped the Monterey Bay area from Ano Nuevo to Moss landing between August and December 2009 using a SEA SWATHplus interferometric sonar system. Data were collected as part of the cooperative California Seafloor Mapping program, during field activities S-7-09-MB and S-10-09-MB.

Sound velocity profile (SVP) measurements were collected on average every two hours throughout the survey. A total of 438 SVPs were collected for this survey. 114 SVPs were collected during cruise S-7-09-MB and 324 SVPs were collected during S-10-09-MB. In general, SVPs were collected every 2 hours, or when the survey vessel moved to a different survey block. Typically two SVPs were collected every four lines. Water column sound velocity profiles varied significantly throughout the survey, however this frequency of SVP collection was sufficient to correct for variations in sound velocity. Only one line from cruise S-7-09-MB (BlockA_230_044) shows an artifact from an uncorrected sound velocity error (smile), for part of it's length. Insufficient sound velocity data were available to correct this line, and no attempt was made to synthesize data.

SVPs were collected with an Applied Micro Systems, SvPlus 3472. This instrument provides time-of-flight sound velocity measurements using invar rods with a sound velocity accuracy of +/- 0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an accuracy of 0.15% (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 C (Applied Microsystems Ltd., 2005). In addition, an Applied Micro Systems Micro SV accurate to +/- 0.03 m/s was deployed on the transducer frame for real-time sound velocity adjustments at the transducer-water interface.

Data in these data tables are recorded in the following fields:

  #DateTime - date and timestamp for the SVP data
  Pressure(dBars) - This field is actually water depth in meters
  SoundVelocity(m/s) - Sound velocity in m/s
  Temperature(C) - temperature in degrees C
  Battery(Vdc) - battery voltage

SVPs taken at this density comprise a largely unexplored dataset that provides insight into spatial and temporal temperature variation within the Monterey Bay National Marine Sanctuary between mid-August and late December, 2009.

Supplemental_Information:

Information about August-September 2009 field activity data collection at <http://walrus.wr.usgs.gov/infobank/s/s709mb/html/s-7-09-mb.fmeta.faq.html>.

Information about October - December field activity data collection at <http://walrus.wr.usgs.gov/infobank/s/s1009mb/html/s-10-09-mb.fmeta.faq.html>.

[header information example - information varies slightly] #DUMP 3472LOG.RAW #SvPlus S/N 3472 #New cast started on 08-14-09 at 17:19:02 #Sample rate is 15 /second #Depth increment 0.00 #Sound velocity increment 0.00 # #582714.944207046E #4083519.92296003N #DateTime,Pressure(dBars),SoundVelocity(m/s),Temperature(C),Battery(Vdc) [data record example] 08-14-09 17:19:02,0.0,1496.72,15.992,13.15 . . .

Data format:	ASC Size: 1635.635
Network links:	<https://pubs.usgs.gov/ds/514/>

Data format:

ASC Size: 1635.635

Network links:

<https://pubs.usgs.gov/ds/514/>

Monterey Bay SVP data from cruise S-07-09-MB and S-10-09-MB

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