Other ID: 85 Leg 1; FRNL 85-1 F185GM
Status: Completed
Organization(s): USGS, Woods Hole Coastal and Marine Science Center
Funding Program(s): Other (Other)
Principal Investigator(s): Bonnie McGregor
Affiliate Investigator(s): Guy Rothwell - IOS
Information Specialist(s): Other
Data Type(s): Electro-Magnetic: Magnetics, Location-Elevation: Navigation, Seismics: Air Gun / Water Gun, Seismics: Sub Bottom Profiler, Sonar: Sidescan, Sonar: Single Beam
Scientific Purpose/Goals: The purpose of this cruise was to map the sea floor between approximately the shelf edge and the seaward limit of the EEZ using the GLORIA system owned and operated by IOS. Leg 1 focused on the western half of the Gulf of Mexico seaward of Texas and Louisiana abutting GLORIA coverage from a 1982 survey. This portion of the Gulf is dominated by salt tectonics. The area mapped with GLORIA during this leg was 45,000 sq nautical miles.
Vehicle(s):
Start Port/Location: Miami, FL
End Port/Location: New Orleans, LA
Start Date: 1985-08-07
End Date: 1985-09-03
Equipment Used: ABC navigation system, Other, 3.5 kHz, 10 kHz Bathymetry, GLORIA sidescan, Marine magnetometer, Loran-C, Single channel hydrophone, Air gun
Information to be Derived: As part of a cooperative program between the U.S. Geological Survey and the Institute of Oceanographic Sciences (IOS), U.K., a survey of the Exclusive Economic Zone (EEZ) in the Gulf of Mexico was conducted aboard the M/V FARNELLA. The purpose of the cruise was to map the sea floor between approximately the shelf edge and the seaward limit of the EEZ, using the GLORIA (Geologic LOng-Range Inclined Asdic) system owned and operated by IOS. Additional geophysical data collected simultaneously with the sidescan data include: 10 kHz, 3.5 kHz, air gun (160 cubic-inch chamber) with two-channel hydrophone, and magnetometer. Navigation was principally based on Loran-C, although transit satellite and Global Positioning System (GPS) data were also logged for comparison. All geophysical data were recorded digitally on magnetic tape and the airgun data were recorded on analog magnetic tape. A preliminary mosaic of the sidescan data was constructed at sea at a scale of 1:375,000, using an anamorphic camera to adjust the images to the ship's track. Post-cruise image processing and enhancement of the data are planned before construction of the final mosaic.
Summary of Activity and Data Gathered: Hurricane Denny resulted in a loss of 13 hours of operation on August 14, 1985, and Hurricane Elena delayed arrival in New Orleans one day, from September 2 to September 3, 1985. The impact that the warm surface water and strong thermocline present in the Gulf of Mexico in the summer would have on the range of the GLORIA system was not realized. Although GLORIA was run at a 30 sec. repetition rate, 45 km swath width, the maximum swath width actually obtained was 8 km in approximately 1000 m of water. This required reducing the trackline spacing and adding additional tracklines and limited the effort in water depths shallower than 1000 m. Initially much time was spent getting all equipment operational. The GLORIA system suffered from logging problems resulting in a loss of approximately 24 hours of data during the cruise. The longest continuous down time period was 12 hours. Dirt particles in the air being pulled across the recording heads by the air conditioning system appears to have been the major problem. The air gun system was down a total of approximately 24 hours due to compressor, streamer and gun problems. The longest continuous period of down time was 7 hours. The magnetometer required 3 days to get operational initially but this was partly a result of its lower priority. A new computer system was installed for this cruise. Most of the leg was required to get the system operating properly. Navigation has to be plotted by hand for the duration of the cruise. Summary data plots for the cruise, however, were completed with the computer system at the end of the cruise. The data in the western Gulf are very interesting geologically. The Sigsbee Escarpment can be identified on the sonographs with piles of debris in places at its base. A continuous channel can be traced from the shelf edge through the diapir province of the slope, forming a reentrant in the Sigsbee Escarpment, and then meandering seaward across the rise into the deep water of the Gulf. The fan of the Rio Grande has a braided channel system and features which are interpreted to be bedforms on it. Similar bedforms are present seaward of the Sigsbee Escarpment suggesting that strong bottom currents are present in the region.
Staff: Dann Blackwood
Affiliate Staff:
Bonnie McGregor - co-Ch. Sci.
USGS-Miami; Robert Mattick - geologist
USGS-Reston; Guy Rothwell - co-Ch. Sci.
IOS; Derek Bishop - GLORIA engineer
IOS; Alan Gray - airgun tech.
IOS; Quentin Huggett - geologist
IOS; Christopher Jackson - shipboard computing
RVS; Michael Somers - GLORIA engineer
IOS; Ross Walker - GLORIA engineer
IOS; E. Cooper; William Sweet - geologist
MMS; Kim Benjamin - engineer
WHOI
Notes: Data holdings also at PCMSC; added FACS ID to AKA
Bonnie McGreggor and Guy Rothwell; PIs
Platform; Farnella
Original Center People field contained: Dann Blackwood - photographer, Woods Hole.
Project = GLORIA Gulf of Mexico survey 1985, GLORIA Gulf of Mexico survey 1985
Location:
western Gulf of Mexico, Texas, Louisiana, United States, North America, North Atlantic;
| Boundaries | |||
|---|---|---|---|
| North: 28 | South: 25 | West: -96 | East: -88 |
Platform(s):
 Farnella |
Lubinski, D.J., and Twichell, D.C., 1989, Magnetic and bathymetric data from R/V FARNELLA cruises FRNL85-1, 85-2, and 85-3 in the U.S. Gulf of Mexico EEZ: U.S. Geological Survey Open-File Report 89-156, 6 p., URL: https://doi.org/10.3133/ofr89156.
Paskevich, V.F., 1996, Digital mosaics of the GLORIA sidescan sonar data of the Gulf of Mexico: U.S. Geological Survey Open-File Report, https://doi.org/10.3133/ofr96657.
Paskevich, V.F., 2000, Gulf of Mexico GLORIA sidescan sonar geologic interpretation—ArcView data coverages: U.S. Geological Survey Open-File Report 2000-019, https://doi.org/10.3133/ofr0019.
Twichell, D.C. Cross, V.A., Paskevich, V.F., Hutchinson, D.R., Winters, W.J., and Hart, P.E., 2006, GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey: U.S. Geological Survey Open-File Report 2005-1071, DVD-ROM, also available from https://doi.org/10.3133/ofr20051071.
Twichell, D.C., McGregor, B.A., and Lubinski, D.J., 1989, Seismic-reflection data from R/V FARNELLA cruises FRNL82-7, FRNL85-1, FRNL85-2, and FRNL85-3A in the U.S. Gulf of Mexico EEZ: U.S. Geological Survey Open-File Report 89-549, 7 p., URL: https://doi.org/10.3133/ofr89549.
Twichell, D.C., and Paskevich, V.F., 1996, GLORIA sidescan-sonar field data and navigation data collected in the Gulf of Mexico during R/V FARNELLA cruises in 1982 and 1985: U.S. Geological Survey Open-File Report 96-707, https://doi.org/10.3133/ofr96707.
| Title | Survey Equipment | Description |
|---|---|---|
| Cruise report | (document not focused on specific equipment) | Chief Scientist's cruise report includes personnel and a summary for each leg of the operation (covers 2 cruises - 85027 and 85028) as well as trackmaps. |
| Survey Equipment | Survey Info | Data Type(s) | Data Collected |
|---|---|---|---|
| ABC navigation system | --- | Navigation | |
| Other | --- | --- | --- |
| 3.5 kHz | --- | Sub Bottom Profiler | |
| 10 kHz Bathymetry | --- | Single Beam | 1985-027-FA-BA-001 (Digital tape(s) of GLORIA, NV,BT, GULF COMPOSITE, NV/BATHY/MAG, ) NGDC MGD77 data 1985-027-FA-BA-002 (CD ROM disk of GLORIA IMAGES, GLORIA ATLANTIC GEOTIFF, GLORIA GULF MEXICO GEOTIFF, GLORIA/MOSAIC 1-16, ) |
| GLORIA sidescan | --- | Sidescan | 1985-027-FA-SO-002 (CD ROM disk of GLORIA IMAGES, GLORIA ATLANTIC GEOTIFF, GLORIA GULF MEXICO GEOTIFF, GLORIA/MOSAIC 1-16, ) GLORIA sidescan data |
| Marine magnetometer | --- | Magnetics | NGDC MGD77 data |
| Loran-C | --- | Navigation | 1985-027-FA-LN-001-01 (Trackline map for R/V FARNELLA cruise FRNL85-1) 1985-027-FA-SE-003 (Digital tape(s) of GLORIA, NV,BT, GULF COMPOSITE, NV/BATHY/MAG, ) Nav data |
| Single channel hydrophone | --- | Air Gun / Water Gun Boomer Bubble Gun Sparker Sub Bottom Profiler | 1985-027-FA-SE-002 (analog tape of seismic data) 1985-027-FA-SE-001 (microfilm of ) 1985-027-FA-SE-004 (Collection of paper record displays of seismic data.) 1985-027-FA-SE-004-01 (Electronic scans of some paper seismic profiles.) |
| Air gun | --- | Air Gun / Water Gun |
