RV Farnella 2/81
Cruise summary report
|Ship name (ship code)||RV Farnella (74AE)|
|Cruise period||1981-10-16 — 1981-11-05|
|Port of departure||St John, Canada|
|Port of return||Ponta Delgada, Portugal|
|Objectives||GLORIA. Geophysical studies of the continental margin on the eastern edge of the Grand Banks.
The main objectives were to study the structural and sedimentary processes which have shaped the continental margin to the east of the Grand Banks between 41° and 52° N, and to compare the geological history of this margin with that of its conjugate on the eastern side of the Atlantic.
Sailed to start of survey plan. GLORIA launched in high winds and poor visibility and 3.5kHz, PES and airgun deployed. The 3.5 kHz interfered with GLORIA and was abandoned. 19th October, gear reocover for engine repairs. 22nd October, the PDP11/CAMAC digitiser and SE 8000 tape recorder used to take digital GLROIA records for the first time. 30th October, the Grand Banks survey was complete including a box survey of the Newfoundland Seamounts. Course set towards Mid-Atlantic IPOD sites with GLORIA, PES and magnetometer streamed and SRP and 3.5 kHz recovered. Following day the magnetometer and GLORIA recovered due to worsening weather. GLORIA launched for the IPOD site survey on 2nd November and completed on 3rd. All gear including PES recovered and set sail for Ponta Delgada, Portugal.
5 sonobuoy stations: 6, 7 and 8 (1000m3 airgun), 10 and 11 (300m3 airgun).
GLORIA - 2-second pulse every 40 seconds used. Trouble was experienced with interference from the SRP but SRP not normally run. Problem of apparent beam widening, 47 tapes (3 digital), 8 hours each. 4600 nautical miles in total during cruise of seismic reflection data logged by the 3.5 kHz high resolution SRP. Compressors gave little trouble and all faults recorded were electrical. Each airgun was fun for 5 days. Barringer magnetometer performed well. The gravimeter produced a noisy but acceptable record, average errors of 3.66m gal. 5 sonobuoy stations successfully occupied during the cruise. 1 further buoys failed to transmit useful data.
|Chief scientist||Jack A Revie (Institute of Oceanographic Sciences Wormley Laboratory)|
|Cruise report||(0.64 MB)|
|General||North Atlantic Ocean|
|Geology and geophysics|
|Multi-beam echosounding||Quantity: track kilometres = 5600|
Description: in total during 1/81 and 2/81
|Long/short range side scan sonar||Quantity: track kilometres = 5790|
Description: GLORIA, 47 tapes (3 digital) of 8hours each, ~3600 miles
|Multichannel seismic reflection||Quantity: track kilometres = 7400|
Description: 4600 miles in total during 1/81 and 2/81, 2 channel array SPR used
|Gravity measurements||Quantity: track kilometres = 15560|
Description: in total during 1/81 and 2/81, average errors of 3.66 m gal
|Magnetic measurements||Quantity: track kilometres = 10370|
Description: in total during 1/81 and 2/81, Barringer magnetometer
|Other geological/geophysical measurements||Quantity: number of deployments = 5|
Description: sonobuoys, 3 with 1000m3 and 2 with 300m3 airgun