USGS CMG L-2-84-AN Metadata

Seismic reflection profiles, gravity, magnetics, lithology,
and bathymetry.

Approximately 2,350-line km of multichannel
seismic-reflection data, as well as 4,500 km of other geophysical
profile data including gravity, magnetic gradiometer, and
echo-sounding profiles for the western Ross Sea, Antarctica
were collected.

 The seismic source consisted of a tuned five-airgun array
totaling 1,311 cu.in. pressurized to 1,900 psi, towed at a
depth of 10.5 m.

The receiver consisted of a 24-channel
hydrophone streamer, with 100-m group lengths containing 60
hydrophones in each group.

The streamer was towed at a
depth of 12.5 m.

The data were recorded with a GUS Model
HDDR-4200 recording system.

All lines were recorded to 12
sec, with exception of Line 407 (15 sec) and Line 419 (8
sec).
Magnetic data were recorded continuously with a
Geometrics proton-procession gradiometer to remove the large
temporal magnetic variations commonly recorded at polar
latitudes.

The gradiometer system consisted of two proton-precession
magnetometers separated horizontally by 500 ft
(152 m) with the forward sensor lying 225 m aft of the ship.

Both sensors were towed at a depth of approximately 20-40m.
Data were sampled at 4-sec intervals.
Gravity data were
recorded continuously with a LaCoste and Romberg sea
gravimeter (S53) on a two-axis stabilized platform.

The data were collected at 20-sec intervals and subsequently
desampled to 2 min or greater for plotting and modeling.

! Converted to time format with year at start.
!
DATA COLLECTION OVERVIEW  (use NGDC GEODAS CD to retrieve data)

MCG Data Collection ID ---         L284AN
Institution Data Collection ID --- L284AN
NGDC ID ---                        06050069
Funding ---                        (unspecified)
Project, Cruise & Leg ---          ANTARCTICA - ROSS SEA
Study region ---                   -43.00000,-78.00000,+163.00000,-173.00000
Chief Scientist(s) ---             ALAN COOPER,FRED DAVEY
Date field data collection started --- 02/03/84     LV MCMURDO
Date field data collection ended ---   03/03/84     ARRIVE LYTTLETON, N.Z.
Parameters surveyed ---
   Bathymetry:                     surveyed, contained in data file
   Magnetics:                      surveyed, contained in data file
   Gravity:                        surveyed, contained in data file
   High-resolution seismics:       (unspecified)
   Deep penetration seismics:      (unspecified)
Format --- 

(I1,A8,F5.2,4I2,F5.3,F8.5,F9.5,I1,F6.4,F6.1,I2,i1,3F6.1,I1,F5.1,F6.0,F7.1,F6.1,F5.1,A8,4I1)
Date of data input to NGDC ---     08/05/87
Contributing institution ---       USGS Branch of Pacific Marine Geology
Country ---                        United States

Navigation instrumentation ---     NAV SATELLITE / INTEGRATED NAV
Position determination method ---  (unspecified)

Bathymetry instrumentation ---            12KHZ
Additional forms of bathymetric data ---  ANALOG
General rate of bathymetry in file ---    0.9 minutes
General collection rate of bathymetry --- (unspecified)
Assumed sound velocity ---                (unspecified)
Bathymetric datum code ---                No correction applied (sea level)
Bathmetry interpolation scheme ---        (unspecified)

Magnetics instrumentation ---            (unspecified)
Additional forms of magnetics data ---   (unspecified)
General rate of magnetics in file ---    0.9 minutes
General collection rate of magnetics --- (unspecified)
Magnetic sensor tow distance ---         (unspecified)
Magnetic sensor depth ---                (unspecified)
Two sensor horizontal separation ---     (unspecified)
Residual magnetics reference field ---   (unspecified)
Method of applying residual field ---    (unspecified)

Gravity instrumentation ---            SHIPBOARD GRAVITY METER
Additional forms of gravity data ---   ANALOG RECORDS
General rate of gravity in file ---    0.7 minutes
General collection rate of gravity --- (unspecified)
Theoretical gravity formula ---        (unspecified)
Reference system ---                   (unspecified)
Corrections applied ---                (unspecified)
Starting land tie ---                  (unspecified)
Ending land tie   ---                  (unspecified)

Seismic instrumentation --- 3.5KHZ,24 CHAN,SNGL CHAN AIRGUN,UNIBOOM
Formats of seismic data --- ANALOG

Notes ---
SONOBOUY

Davey, F.J., and Cooper, A.K., 1984, U.S.G.S. geoscience survey; Ross Sea, 
Antarctica:
New Zealand Antarctic Record, v. 5, no. 3, p. 41-43. 


Cooper, Allen K., 1984, Geophysical and geologic studies of Ross Sea continental 
margin,
Antarctica, in 1984 American Association of Petroleum Geologists annual 
convention with
divisions, Society For Sedimentary Geology/EMD/DPA: American Association of 
Petroleum
Geologists Bulletin, v. 68, no. 4, p. 465.


Cooper, A.K., and Davey, F.J., 1985, Marine geological and geophysical 
investigations in
the Ross Sea, Antarctica: Antarctic Journal of the United States, v. 19, no. 5, 
p. 80-82.


Cooper, Alan K., and Davey, F.J., 1985, Episodic rifting of Phanerozoic rocks in 
the
Victoria Land Basin, western Ross Sea, Antarctica: Science, v. 229, no. 4718, p. 
1085-1087.


Cooper, Alan K., Mann, D.M., Childs, Jonathan R., and Davey, F.J., 1986, Marine 
geophysical
data from the western Ross Sea, Antarctica: U.S. Geological Survey Open-File 
Report 86-0634, 14 p.


Dadisman, S.V., Ryan, H.F., and Mann, D.M., 1987, Recording and processing 
procedures for
multichannel seismic-reflection data collected in the western Ross Sea, 
Antarctica, in Cooper, Alan
K., and Davey, Frederick J., eds., The Antarctic continental margin; geology and 
geophysics of the
western Ross Sea: Circum-Pacific Council for Energy and Mineral Resources, Earth 
Science Series,
v. 5B, p. 17-26.


Hansen, R.O., and Childs, J.R., 1987, The Antarctic continental margin magnetic 
gradiometer data;
suppression of time variations, in Cooper, Alan
K., and Davey, Frederick J., eds., The Antarctic continental margin; geology and 
geophysics of the
western Ross Sea: Circum-Pacific Council for Energy and Mineral Resources, Earth 
Science Series,
v. 5B, p. 139-153.


Behrendt, J.C., Cooper, Alan K., and Yuan, A., 1987, Interpretation of marine 
magnetic gradiometer
and multichannel seismic-reflection observations over the western Ross Sea 
shelf, Antarctica, in
Cooper, Alan K., and Davey, Frederick J., eds., The Antarctic continental 
margin; geology and
geophysics of the western Ross Sea: Circum-Pacific Council for Energy and 
Mineral Resources,
Earth Science Series, v. 5B, p. 155-177.


Barron, J.A., and Burckle, L.H., 1987, Diatoms from the 1984 USGS Antarctic 
cruise in the Ross
Sea, in Cooper, Alan K., and Davey, Frederick J., eds., The Antarctic 
continental margin; geology
and geophysics of the western Ross Sea: Circum-Pacific Council for Energy and 
Mineral Resources,
Earth Science Series, v. 5B, p. 225-230.


Wong, F.L., Barrett, P.J., Gamble, J., and Howell, D.G., 1987, Petrography of 
rock samples
dredged from Iselin Bank, Ross Sea, Antarctica, in Cooper, Alan
K., and Davey, Frederick J., eds., The Antarctic continental margin; geology and 
geophysics of the
western Ross Sea: Circum-Pacific Council for Energy and Mineral Resources, Earth 
Science Series,
v. 5B, p. 231-253.


Wold, Richard J., and Cooper, Alan K., 1989, Marine magnetic gradiometer; a tool 
for the
seismic interpreter: Geophysics: The Leading Edge of Exploration, v. 8, no. 8, 
p. 22-27.


Bartek, Louis R., and Anderson, John B., 1990, Neogene stratigraphy of the Ross 
Sea continental
shelf; revelations from Leg 2 of the 1990 Ross Sea expedition of the R/V Polar 
Duke, in
Cooper, Alan K., and Webb, Peter N., eds., International workshop on Antarctic 
offshore acoustic
stratigraphy (Antostrat); overview and extended abstracts: U.S. Geological 
Survey Open-File Report
90-0309, p. 53-62.


Childs, Jonathan R., and Cochrane, Guy R., 1990, Sonobuoy seismic data over the 
Ross Sea and Wilkes
Land continental margins, in Cooper, Alan K., and Webb, Peter N., eds., 
International workshop on
Antarctic offshore acoustic stratigraphy (Antostrat); overview and extended 
abstracts: U.S.
Geological Survey Open-File Report 90-0309, p. 97-101.


Cochrane, Guy R., Cooper, Alan K., Childs, Jonathan R., and Hart, Patrick E., 
1992,
USGS seismic refraction surveys in the Ross Sea, 1984-1990: U.S. Geological 
Survey
Open-File Report 92-0556, 17 p.


http://www.ngdc.noaa.gov/mgg/fliers/87mgg09.html