Skip USGS links group
U.S. Geological Survey - science for a changing world
MWRA Logo and link to MWRA Home Page  USCG Logo and link to USCG Home Page

Woods Hole Science Center

End of USGS links group

Time-Series Photographs of the Sea Floor in Western Massachusetts Bay, Version 1, 1989-1993


Comments on Time-Series Photographs

Skip navigational side bar

Time-series 338 (December 5, 1989 - March 28, 1990)

  • No oceanographic data are available for this deployment because of a failure in the data recording electronics. Thus the data panel beneath the photograph is blank. There is beam attenuation data that begins in frame 235.
  • The red haze in the upper right corner of the movie frame is an artifact caused by light leaking from the LED data chamber and exposing the film.
  • The sea floor in several fames in this time series are poorly illuminated, for example frames 026-036, 132-139, and 217-227. The decreased light from the strobe may be caused by animals or plants blocking the strobe light, or by some malfunction of the strobe light that produced low light for these photographs.
  • A skate remains in nearly the same location on the sea floor in frames 116-125
  • Increased turbidity in the water column, most likely caused by a storm, is visible in frames 228-231.
  • The 5/8-in. nylon line used to recover the tripod spills prematurely from the rope canister during the sediment resuspension event beginning in frame 228. The line is visible on the sea floor in frames 230-255 and occasionally thereafter. This tripod was recovered with the aid of divers.
  • Increased turbidity in the water column and movement of the recovery line on the sea floor is visible in frames 332-339.

Time-series 347 (July 10, 1990 - October 23, 1990)

  • The red haze in the upper right corner of the movie frame is an artifact caused by light leaking from the LED data chamber and exposing the film.
  • A resuspension event begins in frame 085 that is correlated with increase in bottom pressure variance (indicating surface waves).
  • Small fish begin to appear in the photographs at frame 105 and are observed throughout the remainder of the observation period, sometimes in large numbers (for example frame 196 - 197).
  • The attachment for the compass fails between frames 131 and 132 and the compass falls to the sea floor.
  • Temperature, current, and speed data are lacking after frame 202 due to a failure in the data recording electronics.
  • A resuspension event begins in frame 221 as indicted by the turbid water.

Time-series 358 (October 24, 1990 - February 2, 1991)

  • The sea floor is illuminated by the strobe light only in a circle in the left center of the photograph. This poor lighting is most-likely due to low battery power supplying the strobe. The light decreased throughout the deployment and the illumination is not sufficient to see the sea floor by frame 300.
  • A resuspension event begins in frame 104 that is correlated with increase in bottom pressure variance (indicating increased surface waves).
  • A resuspension event begins in frame 166 that is correlated with increase in bottom pressure variance (indicating increased surface waves).
  • Increased turbidity is visible despite the poor strobe illumination in frame 326.

Time-series 374 (February 12, 1991 - June 11, 1991)

  • The data chamber ID number was mistakenly set at 76; it should be 74 for deployment 374.
  • The lower cage of the Benthic Acoustic Stress Sensor (BASS), used to measure current, is visible at the right edge of the photograph.
  • Increased turbidity is apparent in frames 8-12, 79-81, 122-137, 272-276 and 454-460.
  • There is no temperature data after frame 129, pressure after frame 46, light transmission after 287, and current after 450 due to failures in the data-recording electronics.
  • A large number of fish appear in the photographs from frame 280 to 440. Many are near the camera lens and thus appear large.

Time-series 383 (June 11, 1991 - October 15, 1991)

  • On the right side of the photograph, there are occasionally portions of red digits that are artifacts from the data chamber.
  • There is a shadow in the upper left corner of the photographs caused by something blocking the illumination from the strobe.
  • There are no temperature or beam attenuation measurements for this deployment.
  • There are a number of small fish in the photographs starting in frame 024.
  • The illumination of the sea floor from the strobe light begins to decrease around frame 400. The illumination progressively decreases; the photographs are illuminated only in the center and are nearly black by frame 487 near the end of the deployment. The decrease in illumination is most-likely due to fouling during this summer deployment, low battery power supplying the strobe, or both.

Time-series 389 (October 16, 1991 - October 30, 1991)

  • The lower cage of the Benthic Acoustic Stress Sensor (BASS), used to measure current, is visible at the right center of the photograph.
  • The light red haze along the right side of the photograph is an artifact caused by light leaking from the LED data chamber.
  • Increased turbidity is apparent in frames 1-50 and 71-84.
  • The photographic and data records end during the storm that begins on October 28, 1991. The tripod frame is tipped over by the large wave currents during this storm, which was the second-largest storm during the period 1990-2006 as determined by bottom wave stress.

Time-series 400 (June 2, 1992 - October 10, 1992)

  • The compass in the field of view is fixed in this deployment.
  • There is a shadow that cuts across the lower right corner of the photographs that grows more pronounced during the deployment; this is most likely caused by fouling.
  • Increased turbidity is apparent in frames 022- 030 and 685 - 705.
  • The data ends at frame 677; the pictures continue until frame 736.

Time-series 407 (October 20, 1992 - Febuary 18, 1993)

  • The LED data chamber is overexposed in this film making the timing digits impossible to read.
  • Increased turbidity is apparent in frames 002-016, 077- 100, and 124-125.
  • The tripod is tipped over around frame 170. There is no major storm activity at this time and it is hypothesized that the tripod may have been tipped over by entanglement with lobster gear. The camera continues to operate, although no longer pointed at the bottom, and indicates times of increased turbidity.
  • A northeast storm occurred on December 12 - 14, 1992; this was the largest northeast storm for the period 1990-2006, as determined by wave bottom stress. Increased turbidity is apparent in the frames taken during this storm.
  • Increased turbidity is apparent in frames 171-188, 222- 226, 243-252, 327-333, 383-389, 408 - 431, 525-537, 589 - 618.
  • A lobster pot is visible in frame 253.

Time-series 413 (February 25, 1993 - June 15, 1993)

  • The lower cage of the Benthic Acoustic Stress Sensor (BASS), used to measure current, is visible at the bottom center of the photograph. The BASS sensor casts a shadow to the upper left of the photographs that increases in intensity.
  • The compass is located at the top center of the photograph and is only partially in view; the head of the compass assembly that holds the north-point arrow is not visible in all frames.
  • Three separate storms, accompanied by large bottom-wave currents, occur in frames 19-35, 38-48, and 075-100.
  • Following the storm in frames 38-48 finer-grained sediments has replaced cobbles in a band from the BASS sensor to the middle upper left of the photograph (part of the ring of lowest BASS sensor cage is visible in the bottom center of the photographs).
  • Increased turbidity is apparent in frames 20-33, 38-55, 76-119, 191-198, 258-262, and 344-353.

Jump to top of page
Return to the start page.
Skip Navigation

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey | Coastal and Marine Geology

URL: cmgds.marine.usgs.gov/publications/ds-265/WEBPAGES/comments.html
Page Contact Information: CMGDS Team
Page Last Modified: Wednesday, 06-Dec-2017 11:04:48 EST