Maximum Sensor or Sampling Depth 74.1 m
Minimum Sensor or Sampling Height 10.9 m
Maximum Sensor or Sampling Height 84.9 m
Sea Floor Depth 85.0 m
The salinity data were very noisy and should be treated with caution.
Inspection of the pressure records from this cruise revealed several negative values (by up to 3 dB) at the start of some profiles. Reasonable temperature and salinity values accompanied the negative pressures, which casts some doubt on the accuracy of the pressure calibration. The affected data values have been flagged as suspect.
RRS Challenger 7/83 CTD Data Documentation
Documentation for the CTD data collected on RRS Challenger Cruise 7/83 (May - June 1983) by the Scottish Marine Biological Association, Oban, Argyll, Scotland, UK, under the direction of D. J. Ellett.
The manufacturer's calibration was used to convert the raw data to physical units using the equation below:
Temperature (°C) = (106/Pt -2238.68/55.84)
Temperature (°C) 1.0031 0.0188 0.008
Conductivity (mmho/cm) 1.0011 -0.0023 0.010
Pressure (dbar) 1.0081 0.6970 3.213
Sharples, F. (1987).
A new data bank of SMBA STD/CTD observations in the Rockall Trough 1975-84. SMBA Marine Physics Group Report No. 36.
Graham, J.M., Sharples, F., Meldrum, D.T. and Edwards, A. (1987).
STD observations in the Rockall Trough 1975-77. SMBA Marine Physics Group Report No. 39.
Cruise Name CH7B/83
Principal Scientist(s) Roy Bowers (Scottish Marine Biological Association)
Station Name Ellett Line/Extended Ellett Line Station 4G
Ellett Line/Extended Ellett Line: Station 4G
Station 4G is one of the fixed CTD stations, which together form The Extended Ellett Line. The line lies between Iceland and the Sound of Mull (Scotland) crossing the Iceland Basin and Rockall Trough via the outcrop of Rockall. As part of this initiative, CTD dips, together with associated discrete sampling of the water column, have typically been carried out annually at this station since September 1996.
Prior to September 1996, Station 4G was part of a shorter repeated survey section, consisting of 35 fixed stations, known as The Ellett Line (originally termed the Anton Dohrn Seamount Section). This line incorporated those stations across the Rockall Trough and Scottish shelf between Rockall and the Sound of Mull and was visited at regular intervals (usually at least once a year) between 1975 and January 1996. During this period Station 4G was also referred to as Station C3.
Appendix 1: Ellett Line/Extended Ellett Line Station 4G