RRS Discovery D155
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Discovery (74E3) |
| Cruise identifier | D155 |
| Cruise period | 1985-05-17 — 1985-06-10 |
| Status | Completed |
| Port of departure | Govan, United Kingdom |
| Port of return | Falmouth, United Kingdom |
| Purpose | Research |
| Objectives | The main objective of this cruise was to investigate the structure of the continent-ocean crustal transition from Hatton Bank to the Atlantic on the northwest UK continental margin. The main techniques were: to shoot a grid of multichannel normal incidence seismic profiles to determine the thickness and shape of sediment crustal reflectors; to run a number of two-ship synthetic aperture profiles (SAP) across the margin to image the deep structure and to measure lateral variations in velocity; to shoot a number of expanding spread profiles (ESP) along and across using large airguns or explosive sources to find the variation of velocity with depth; and to measure underway bathymetry, magnetic and gravity fields to help constrain models of the crustal structure.
Other objectives included determination of the crustal structure in Rockall Trough by an explosion ESP, to run a long two-ship synthetic aperture profile from Hatton Bank to Rockall Trough across Rockall Plateau and the Hatton-Rockall Trough, and to study the variations in crustal structure across small Atlantic fracture zones. |
| Chief scientist | Robert S White (University of Cambridge Department of Earth Sciences) |
| Cruise report |  (0.62 MB) |
| Ocean/sea areas | |
| General | North East Atlantic Ocean (limit 40W) |
| Specific | Northeastern Atlantic - Hatton Bank - Rockall area of the N.W. UK Continental Margin |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Quantity: track kilometres = 5797 Description: T only |
| Geology and geophysics | |
| Multi-beam echosounding | Quantity: track kilometres = 5797 |
| Single channel seismic reflection | Quantity: track kilometres = 2532 |
| Seismic refraction | Quantity: track kilometres = 1111 |
| Gravity measurements | Quantity: track kilometres = 5797 |
| Magnetic measurements | Quantity: track kilometres = 5797 |
