Magnetic Data Over Gulf of Maine and Adjacent Land Areas: Preparation of a Data Base For Construction of a 1:500,000 Magnetic Anomaly Map

Magnetic data over the continental margin of eastern Canada: preparation of a data base and construction of a 1:5 million magnetic anomaly map

10.4095/130339 ◽

1987 ◽

Cited By ~ 2

Author(s):

J Verhoef ◽

R Macnab

Keyword(s):

Data Base ◽

Magnetic Anomaly ◽

Continental Margin ◽

Magnetic Data ◽

Eastern Canada ◽

Anomaly Map

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GEOLOGIC IMPLICATIONS OF AEROMAGNETIC DATA FOR THE EASTERN CONTINENTAL MARGIN OF THE UNITED STATES

Geophysics ◽

10.1190/1.1439970 ◽

1968 ◽

Vol 33 (5) ◽

pp. 755-780 ◽

Cited By ~ 79

Author(s):

Patrick T. Taylor ◽

Isidore Zietz ◽

Leonard S. Dennis

Keyword(s):

New England ◽

Continental Slope ◽

Magnetic Anomaly ◽

East Coast ◽

Gulf Of Maine ◽

The United States ◽

Structural Features ◽

Magnetic Data ◽

Aeromagnetic Survey ◽

Line Spacing

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.

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Presentation of magnetic anomaly map data by stereo projection of magnetic shadowgrams

Canadian Journal of Earth Sciences ◽

10.1139/e85-030 ◽

1985 ◽

Vol 22 (2) ◽

pp. 311-314 ◽

Cited By ~ 5

Author(s):

John Broome ◽

Réjean Simard ◽

Dennis Teskey

Keyword(s):

Magnetic Anomaly ◽

Geological Mapping ◽

Geological Survey ◽

Magnetic Data ◽

Stereo Pair ◽

Magnetic Intensity ◽

Fine Detail ◽

Anomaly Map ◽

Map Data ◽

Shaded Relief

Coloured magnetic maps published at the 1:1 000 000 scale by the Geological Survey of Canada have been found to be useful aids in support of regional geological mapping and compilation projects. However, because of the quantization into colour intervals, some of the fine detail contained in the original magnetic data is lost. These smaller features can be brought out quite effectively with the shaded relief technique, although there is an attendant loss of amplitude information, which can be recovered by means of stereo-shadowgrams. A second shadowgram is produced by offsetting the original shadowgram by an amount proportional to the magnetic intensity of each data point and then the offset and original shadowgrams are viewed as a stereo pair. An example of the effectiveness of these techniques is the detail that can be seen on the shadowgrams and stereo-shadowgrams for the Lockhart River (IMW NP 12/13) and the Thelon River (IMW NQ 12/13/14) map sheets.

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U.S. National Magnetic Anomaly Survey Specifications Workshop Report

Geophysics ◽

10.1190/1.1440991 ◽

1979 ◽

Vol 44 (5) ◽

pp. 991-992

Author(s):

William J. Hinze

Keyword(s):

Magnetic Anomaly ◽

North American ◽

Executive Committee ◽

Ad Hoc ◽

Magnetic Data ◽

Aeromagnetic Data ◽

Workshop Report ◽

The North ◽

Anomaly Map ◽

The U.S

The National Magnetic Anomaly Map (NMAM) Committee, which was formed as an ad hoc committee in 1975 by the SEG Executive Committee, has recommended a multistage program for improving the aeromagnetic data of the U.S. On behalf of the geoscience community, the committee and the U.S. Geological Survey are currently engaged in the preparation of a photo‐composite map of the U.S. derived from publicly available data plus regional magnetic data contributed from the private sector. This map is at present being compiled and is to be pulished by the U.S.G.S. at a scale of [Formula: see text]. Eventually, utilizing this map, the committee plans to assist in the preparation of a North American magnetic anomaly map to supplement the North American tectonic map and the proposed continental gravity anomaly map.

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The World Digital Magnetic Anomaly Map: version 2.1

10.5194/egusphere-egu2020-22098 ◽

2020 ◽

Cited By ~ 1

Author(s):

Jerome Dyment ◽

Yujin Choi ◽

Vincent Lesur ◽

Andreina Garcia-Reyes ◽

Manuel Catalan ◽

...

Keyword(s):

Magnetic Anomaly ◽

International Association ◽

Magnetic Data ◽

International Polar Year ◽

The World ◽

International Polar ◽

Geological Map ◽

Version 2.0 ◽

Anomaly Map ◽

The Antarctic

The World Digital Magnetic Anomaly Map (WDMAM) is an initiative of the IAGA (International Association of Geomagnetism and Aeronomy) supported by the CGMW (Commission for the Geological Map of the World) of UNESCO. The second version was released in 2015 (Dyment et al., 2015; Lesur et al., 2016), and mandate was given to the authors to update this version 2.0 using the same methodology as often as newly available data would make it necessary. Five better datasets justify the preparation and release of version 2.1: (1) the complete digital aeromagnetic map of Brasil made available to CGMW by Ag&#234;ncia Nacional do Petr&#243;leo, G&#225;s Natural e Biocombust&#237;veis; (2) an improved version of the aeromagnetic map of Russia prepared at VSEGEI; (3) the second version of the Antarctic Digital Magnetic Anomaly maP (ADMAP; Golynsky et al., 2018) which construction results from a remarkable international effort during and after the Second International Polar Year; (4) a new map of the Caribbean plate and Gulf of Mexico resulting from the compilation and re-processing of existing marine and aeromagnetic data in the area (Garcia, 2018); and (5) a new compilation of marine magnetic data worldwide. The new map shows significant improvements over the previous versions and will be shortly available at wdmam.org.

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Magnetic anomaly map of the world: merging satellite, airborne, marine and ground-based magnetic data sets

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2007.05.040 ◽

2007 ◽

Vol 260 (1-2) ◽

pp. 56-71 ◽

Cited By ~ 40

Author(s):

Kumar Hemant ◽

Erwan Thébault ◽

Mioara Mandea ◽

Dhananjay Ravat ◽

Stefan Maus

Keyword(s):

Magnetic Anomaly ◽

Magnetic Data ◽

Data Sets ◽

The World ◽

Anomaly Map

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Insights into the Red Sea area from magnetic and gravity analysis

10.5194/egusphere-egu21-10872 ◽

2021 ◽

Author(s):

Ran Issachar ◽

Jörg Ebbing ◽

Dilixiati Yixiati ◽

Nils Holzrichter

Keyword(s):

Magnetic Anomaly ◽

Red Sea ◽

Magnetic Measurements ◽

Magnetic Data ◽

Lithosphere Structure ◽

The North ◽

Southern Central ◽

Anomaly Map ◽

Sea Floor Spreading ◽

Sea Area

We explore the lithosphere structure of the Red Sea using gravity and magnetic data.We re-processed marine data form past surveys conducted during the 70&#8217;s and the 80&#8217;s, available at the NGDC database. By correcting the magnetic measurements according to the DGRF (definitive magnetic reference field), leveling and replacing the long wavelengths with satellite data (LCS1 model) we managed to generate a consistent magnetic anomaly map for the entire length of the Red Sea that is composed of 10 different surveys and contain overs 100,000 measuring points. The magnetic anomaly map highlights structural differences between the southern, central and northern parts of the Red Sea.Using forward gravity approach, constrains from seismic, wells and petrophysical data, and by integrating insights from magnetic analysis, we define the lithospheric model of the Red Sea to address key questions regarding rifting, sea floor spreading and transition processes.&#160; For example, the southern parts of the Red Sea are characterized by shallow and wide asthenosphere upwelling, while in the axial trough lithosphere is thin with thicknesses of less than 15 km. The lithosphere thickness increase asymmetrically towards the rift shoulders. In general, the lithosphere is thicker on the eastern sides than on the western sides. In the central parts of the Red Sea, the lithosphere structure is not significantly different from the southern parts, however, asthenosphere upwelling is slightly narrower. In northern parts of the Red Sea asthenosphere upwelling significantly narrows and focused mainly beneath the axial trough and the lithosphere is thicker. This architecture reflects the currently transition from continental rifting (in the north) to oceanic seafloor spreading (in the south) in the Red Sea.

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