Inversion of Magnetic Measurements of the Swarm A Satellite of the Bangui Magnetic Anomaly

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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Magnetic Measurements Over Darnley Bay, N.W.T.

Canadian Journal of Earth Sciences ◽

10.1139/e72-081 ◽

1972 ◽

Vol 9 (8) ◽

pp. 972-978 ◽

Cited By ~ 4

Author(s):

R. P. Riddihough ◽

G. V. Haines

Keyword(s):

Gravity Anomaly ◽

Magnetic Anomaly ◽

Magnetic Measurements ◽

Three Dimensional ◽

The Body ◽

Magnetic Data ◽

Conical Shape ◽

Level 3 ◽

High Level

Five high level, 3-component, magnetic profiles outline a large magnetic anomaly approximately coincident with the previously observed, 130 mgal, positive gravity anomaly. Three-dimensional interpretations of the magnetic data establish the major dimensions of the source body but do not distinguish between a normal and inverted conical shape. Directions of magnetization derived from the interpretations suggest that the body is geologically related to the Precambrian Franklin Diabases.

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EMAG2: A 2-arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements

Geochemistry Geophysics Geosystems ◽

10.1029/2009gc002471 ◽

2009 ◽

Vol 10 (8) ◽

pp. n/a-n/a ◽

Cited By ~ 259

Author(s):

S. Maus ◽

U. Barckhausen ◽

H. Berkenbosch ◽

N. Bournas ◽

J. Brozena ◽

...

Keyword(s):

Magnetic Anomaly ◽

Magnetic Measurements

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Land Magnetic survey along a profile from Akaz to Rutba town and its applications

Baghdad Science Journal ◽

10.21123/bsj.9.1.63-71 ◽

2012 ◽

Vol 9 (1) ◽

pp. 63-71

Author(s):

Baghdad Science Journal

Keyword(s):

Magnetic Anomaly ◽

Magnetic Measurements ◽

Continuation Method ◽

Vertical Component ◽

Base Station ◽

Western Desert ◽

Magnetic Survey ◽

Fracture Density ◽

Geological Time ◽

Near Surface

A land magnetic survey was carried out along regional profile, which is located at the north part of the Iraqi western desert. It starts from al –Qaam City (at north) toward Rutba City (at south) with a total length of 238km. The survey was carried out along the paved road between the two cities, About 113 measuring points were done with inter-station distance of 2 km (for 198 km) and 2 to 5km (for 40km). Two proton magnetometers were used in this survey. One of them is used for base station monitoring, which was fixed as of Salah Aldin field (Akkas). Its readings were used for diurnal corrections. All magnetic measurements were corrected for normal and topographic corrections. The readings were reduced to a certain base level. The resulted magnetic anomalies show a good correlation with those of Arial - magnetic survey anomalies conducted by (C.G.G, 1974). This is true for those anomalies with wavelength more than 50km. While the land magnetic survey has shown more small anomalies which may reflect near surface sources. In addition, there is a considerable difference between the magnetic intensity values of both surveys. The downward continuation method was used in this study for detecting the depth of magnetic anomaly source. But before applying this method the total magnetic field was converted to its vertical component using computer program packages. The 2.5 mathematical modeling techniques were used for interpreting magnetic anomaly. Several models were suggested according to the geological and geophysical surface and subsurface data. These models clearly suggest that the tectonic of the studied area may be completely affected by deep faults that could reach the basements or even cut it. These faults resulted in tectonic blocks with relative movements that could happen through the geological time, and they may be responsible for the tectonic features of the western desert. These faults could also responsible for the lateral and vertical variations that are noticed in subsurface rocks of the studied area. The subsurface lateral susceptibility variation between the different blocks could result from the variation in physical parameter of the rocks (like porosity, fracture density…) and there is a possibility that rocks beneath 18km (lower crust) still possess some magnetic properties.

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3D reduction of satellite magnetic measurements to obtain magnetic anomaly coverage over Europe

Journal of Geodynamics ◽

10.1016/s0264-3707(01)00058-8 ◽

2002 ◽

Vol 33 (1-2) ◽

pp. 117-129 ◽

Cited By ~ 3

Author(s):

K.I. Kis ◽

G. Wittmann

Keyword(s):

Magnetic Anomaly ◽

Magnetic Measurements

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Research on expanding the range of reproduction of magnetic flux density of the DC field of the state primary standard GET12-2011

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-4-3-7 ◽

2020 ◽

pp. 3-7

Author(s):

Vladlen Ya. Shifrin ◽

Denis I. Belyakov ◽

Alexander E. Shilov ◽

Denis D. Kosenko

Keyword(s):

Magnetic Flux ◽

Magnetic Induction ◽

Frequency Conversion ◽

Magnetic Measurements ◽

Primary Standard ◽

Uncertainty Budget ◽

The State ◽

State Primary Standard ◽

Magnetic Flux Density ◽

Constant Field

The results of works aimed at increasing the level of uniformity of measurements of the magnetic induction of a constant field – the basic value in the field of magnetic measurements. A set of equipment for reproducing a unit of magnetic induction of a constant field in the range of 1–25 mT was created and described. The inclusion of this complex in the State primary standard of units of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient GET 12-2011 will ensure the reproduction and direct transmission of the unit of permanent magnetic induction in the ranges of not only weak (10–3–1 mT), but medium (1–25 mT) and strong (0.025–1 T) magnetic fields. A quantum cesium magnetometer based on the resolved structure of cesium atoms was created to transmit the unit of magnetic induction to the region of medium fields. The procedure for calculating the frequency conversion coefficients to magnetic induction of the created quantum cesium magnetometer is described. The uncertainty budget for reproducing a unit of magnetic induction of a constant field using the created complex is estimated.

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