Monterey Canyon: field work

Between 14 and 22 February 2009 we deployed moorings in the Monterey Canyon from the R/V Wecoma (see map, Figure 1). Instruments and bottom depths were:
  • MP1: McLane Profiler, 488 m
  • LR1: 75 kHz Long Ranger ADCP, 604 m
  • LR2: 75 kHz Long Ranger ADCP, 582 m
  • MP2: McLane Profiler, 370 m
  • LR3: 75 kHz Long Ranger ADCP, 420 m
  • MP3: McLane Profiler, 288 m
  • LR4: 75 kHz Long Ranger ADCP, 307 m
  • WH1: 300 kHz Workhorse Sentinel ADCP, 153 m

Figure 1. Map of the upper Monterey Submarine Canyon (MSC). 

(a)  The red line denotes the canyon's thalweg, or deepest 

path. The along-thalweg distance is marked with black dots at 1-km intervals and labeled at 5-km intervals. Isobaths 

are shown at 50-m intervals, with contours at 200-m intervals bold and labeled at left. The SWIMS3 

tracks are shown in green. At each mooring, the depth-integrated semidiurnal energy and  fl

ux are shown with circles and 

arrows, respectively. Yellow and blue colors indicate time averages over the first spring-neap cycle (yearday 48-62) and


successive three (yearday 62-106), respectively.


Map of Monterey Bay and adjacent region. The blue box shows 

upper MSC as shown in (a). 

Figure 2. A five-day segment of the MP2 measurements. The gray lines in (d) represent the MP's depth along the mooring 

cable, making a round trip from 40 m depth to 10 m height above the bottom each 80 minutes. (a) Eastward velocity. 

(b) Northward velocity. In (a, b), the velocity data between 6-40 m depths are from a 300-kHz ADCP. (c) Temperature. 

Data between 18-40 m depths are from a string of HOBO thermistors. Isotherm contours are shown every 0.5 C. (d) 


Figure 3. A five-day segment of the LR4 measurements. (a) Eastward velocity. (b) Northward velocity. (c) Upward velocity. (d) Temperature at nine depths.

Figure 4. McLane moored profiler (MMP). It carries a Falmouth Scientific acoustic  current meter and a Conductivity-Temperature-Depth instrument (CTD) to measure proles of horizontal velocity, temperature, and salinity.

SWIMS3 survey. Between 4 and 27 April,  Drs. Michael Gregg and Ren-Chieh Lien (APL/UW) and Glenn Carter (UHawaii) conducted intensive measurements with SWIMS3, a depth cycling towed body, and Advanced Microstructure Profilers (AMPs). For contrast with Monterey, SWIMS3 and AMP observations were planned for nearby Ascension, a short, narrow canyon, but heavy swell limited neap observations to 14 microstructure profiles. SWIMS3 runs were made principally across the canyon, starting seaward of the Gooseneck Meander, and continuing landward around the next bend. Most sections were sampled with repeated runs, extending over 25 hours to obtain averages over a cycle of the M2 semi-diurnal tide (Figure 1 green lines). [more information]