Extinct spreading center in the Labrador Sea: Crustal structure from a two-dimensional seismic refraction velocity model

1995 ◽  
Vol 100 (B2) ◽  
pp. 2261-2278 ◽  
Author(s):  
John C. Osler ◽  
Keith E. Louden
Keyword(s):  
Crustal Structure ◽  
Seismic Refraction ◽  
Velocity Model ◽  
Spreading Center ◽  
Labrador Sea ◽  
Two Dimensional

Geophysical Studies in Baffin Bay and some Tectonic Implications

1972 ◽  
Vol 9 (3) ◽  
pp. 239-256 ◽  
Author(s):  
C. E. Keen ◽  
D. L. Barrett ◽  
K. S. Manchester ◽  
D. I. Ross
Keyword(s):  
Oceanic Crust ◽  
Seismic Reflection ◽  
Seismic Refraction ◽  
The Arctic ◽  
Spreading Center ◽  
Labrador Sea ◽  
Baffin Bay ◽  
Definitive Evidence ◽  
Nares Strait ◽  
The North

A recent seismic refraction experiment in the deep central region of Baffin Bay showed that it is underlain by oceanic crust. This paper describes the results of gravity, magnetic, and seismic reflection profiling measurements in the bay. There is no definitive evidence for a buried ridge or for magnetic lineations in the center of the area. The magnetic and gravity anomaly fields have been used to define the boundary between the oceanic and continental crust around the bay and therefore the extent of oceanic crust presumed to have been formed by sea-floor spreading. Some of the characteristics of the seismic reflection lines across the continental margins, perhaps typical of this area, are also discussed. The results have been used to reconstruct the history of opening of Baffin Bay in conjuction with geophysical measurements in the Labrador Sea to the south and over the Alpha Ridge in the Arctic Ocean to the north. An attempt has been made to reconcile the geometry of opening with continental geology. Two phases of spreading are suggested. The first involves openings, in both the Labrador Sea and in Baffin Bay, about a pole in the Canadian Arctic Islands. The second, most recent stage of opening, requires that the Nares Strait was once a transform fault, perhaps connecting a Baffin Bay spreading center to the Alpha Ridge to the north.

scholarly journals The oceanic crustal structure at the extinct, slow to ultraslow Labrador Sea spreading center

2015 ◽  
Vol 120 (7) ◽  
pp. 5249-5272 ◽  
Author(s):  
Matthias Delescluse ◽  
Thomas Funck ◽  
Sonya A. Dehler ◽  
Keith E. Louden ◽  
Louise Watremez
Keyword(s):  
Crustal Structure ◽  
Spreading Center ◽  
Labrador Sea ◽  
Oceanic Crustal Structure

Crustal structure of the Reykjanes Ridge near 62°N, on the basis of seismic refraction and gravity data

2007 ◽  
Vol 43 (1) ◽  
pp. 55-72 ◽  
Author(s):  
Wolfgang R. Jacoby ◽  
Wilfred Weigel ◽  
Tanya Fedorova
Keyword(s):  
Crustal Structure ◽  
Gravity Data ◽  
Seismic Refraction ◽  
Reykjanes Ridge

Reconnaissance seismic refraction-reflection surveys in northwestern New Mexico

1984 ◽  
Vol 74 (4) ◽  
pp. 1263-1274
Author(s):  
Lawrence H. Jaksha ◽  
David H. Evans
Keyword(s):  
New Mexico ◽  
Wave Velocity ◽  
Lower Crust ◽  
Seismic Waves ◽  
Seismic Refraction ◽  
Velocity Model ◽  
P Wave ◽  
Uppermost Mantle ◽  
P Wave Velocity ◽  
Crustal Thinning

Abstract A velocity model of the crust in northwestern New Mexico has been constructed from an interpretation of direct, refracted, and reflected seismic waves. The model suggests a sedimentary section about 3 km thick with an average P-wave velocity of 3.6 km/sec. The crystalline upper crust is 28 km thick and has a P-wave velocity of 6.1 km/sec. The lower crust below the Conrad discontinuity has an average P-wave velocity of about 7.0 km/sec and a thickness near 17 km. Some evidence suggests that velocity in both the upper and lower crust increases with depth. The P-wave velocity in the uppermost mantle is 7.95 ± 0.15 km/sec. The total crustal thickness near Farmington, New Mexico, is about 48 km (datum = 1.6 km above sea level), and there is evidence for crustal thinning to the southeast.

scholarly journals A Seismic Refraction Study of the Crust and Upper Mantle in the Vicinity of Bass Strait

1969 ◽  
Vol 22 (5) ◽  
pp. 573 ◽  
Author(s):  
R Underwood
Keyword(s):  
Crustal Structure ◽  
Upper Mantle ◽  
Seismic Refraction ◽  
Travel Times ◽  
Crust And Upper Mantle ◽  
Australian Institute ◽  
First Arrival Travel Times ◽  
First Arrival ◽  
Future Work

A reconnaissance seismic refraction study of the crust and upper mantle of Bass Strait and adjacent land was undertaken in 1966 under the sponsorship of the Geophysics Group of the Australian Institute of Physics. The shot locations and times, the station locations, distances, and first arrival travel times are presented. Analysis of these data is described; they indicate a P n velocity below 8 km sec-I. Time terms are less than expected and do not agree with previous work. Crustal thicknesses cannot be computed until studies of upper crustal structure are made. These, and several mantle refraction studies, are suggested for future work.

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