Analysis of multipath scintillations from long range acoustic transmissions on the New England continental slope and shelf

2005 ◽  
Vol 117 (3) ◽  
pp. 1038-1057 ◽  
Author(s):  
Andrew Fredricks ◽  
John A. Colosi ◽  
James F. Lynch ◽  
Glen Gawarkiewicz ◽  
Ching-Sang Chiu ◽  
...  
2018 ◽  
pp. 223-265
Author(s):  
Ronald T. Marple ◽  
James D. Hurd, Jr. ◽  
Robert J. Altamura

 Enhancements of recently available high-resolution multibeam echosounder data from the western Gulf of Maine and Atlantic continental margin and light detection and ranging (LiDAR) and digital elevation model data from southeastern Quebec (Canada) and the northeastern United States have revealed numerous ring-shaped morphological features and interpreted small seamounts between the Monteregian Hills igneous province and the New England seamounts. The morphological features onshore are mainly ring-shaped depressions, several of which surround mapped igneous intrusions in the Monteregian Hills igneous province and White Mountain magma series. Most of the rings offshore are also depressions, although a few rings are curved ridges above the seafloor. The largest ring in the western Gulf of Maine is the 30-km-diameter Tillies ring that lies 20 km east of Cape Ann, MA. Several small (<3 km in diameter) round, flat-topped submerged hills that we interpret to be volcanic necks are also present beneath the western Gulf of Maine. The rings between Cape Cod and the continental slope are more subtle because of thicker sediments and poorer spatial resolution of the sonar data in this area. The southernmost ring-shaped features are located on the continental slope and upper continental rise and coincide with the northwestern end of the New England seamount chain. The concentration of these features between the Monteregian Hills igneous province and the New England seamounts suggests that they are igneous features that may be associated with the New England hotspot track. 


Geophysics ◽  
1968 ◽  
Vol 33 (5) ◽  
pp. 755-780 ◽  
Author(s):  
Patrick T. Taylor ◽  
Isidore Zietz ◽  
Leonard S. Dennis

An aeromagnetic survey extending from the Gulf of Maine to the tip of Florida was conducted by the U. S. Naval Oceanographic Office between 1964 and 1966. Flight traverses were flown in a northwesterly direction at right angles to the geologic grain. The flight lines were approximately 800 km long and had an 8‐km separation. The survey traversed part of the New England, Piedmont, and Coastal Plain provinces and extended some 320 km beyond the continental shelf into the Atlantic Ocean. Despite the wide flight‐line spacing, numerous geological and structural features became apparent from this survey. Interpretation of these features was aided by using the available gravity and seismic data in addition to the State and Provincial geologic maps. The residual aeromagnetic map shows a continuous magnetic high on or near the continental slope as far south as the 31st parallel. At about the 36th parallel, this east‐coast magnetic anomaly splits into two branches, and both of them parallel the 850‐fathom contour. At the 31st parallel, the outer branch of the anomaly swings westward and crosses the coastline near Brunswick, Georgia. This continuous magnetic anomaly may result from an igneous intrusive body that parallels the edge of the pre‐Paleozoic continental landmass. These magnetic data suggest that Florida and part of Georgia were added to the paleo‐continent in pre‐Paleozoic time. Landward from the east‐coast anomaly, the magnetic field is quite variable, whereas oceanward it has an extremely small gradient. The absence of magnetic anomalies east of the continental slope suggests that in this region layer 2 may be composed of metamorphosed basalt. The characteristic magnetic patterns observed over the Piedmont and New England provinces extend oceanward to the east‐coast anomaly.


Science ◽  
1963 ◽  
Vol 141 (3578) ◽  
pp. 358-359 ◽  
Author(s):  
R. L. Wigley

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