RRS John Murray JM8/69 Leg 2
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS John Murray (74MJ) |
| Cruise identifier | JM8/69 Leg 2 |
| Cruise period | 1969-10-11 — 1969-10-21 |
| Status | Completed |
| Port of departure | Barry, United Kingdom |
| Port of return | Barry, United Kingdom |
| Purpose | Research |
| Objectives | 1) To measure the noise levels of towed hydrophone arrays under different conditions including ship speed.
2) To record the noise spectrum of the ship under different engine conditions, 3) To make extensive tests of recent design modifications to the air-gun and to test its reliabilty. 4) To obtain Grab samples from five areas of small sand waves to the south of the Isle of Wight. |
| Chief scientist | Brian S McCartney (National Institute of Oceanography) |
| Cruise report |  (0.31 MB) |
| Ocean/sea areas | |
| General | English Channel |
| Specific | Isle of Wight and Channel Islands |
| Measurements | |
| Biology and fisheries | |
| Gear research | Description: 9 N.I.O hydrophones ranging in size were towed and noise spectra obtained at 3 ship speeds |
| Gear research | Description: Solenoid triggered air guns tested: solenoids; top liners; leakage, lower and upper flange |
| Geology and geophysics | |
| Grab | Quantity: number of hauls = 33 Description: sediment samples |
| Single channel seismic reflection | Description: 9 N.I.O hydrophones ranging in size were towed and noise spectra obtained at 3 ship speeds |
| Magnetic measurements | Description: 9 N.I.O hydrophones ranging in size were towed and noise spectra obtained at 3 ship speeds |
| Other geological/geophysical measurements | Description: 'Ewing' type air gun high versus low pressure readings obtained |
