scispace - formally typeset
SciSpace - Your AI assistant to discover and understand research papers | Product Hunt

Journal ArticleDOI

Lithospheric magnetic mapping of the northern Caribbean region

01 Jan 2013-Geologica Acta (Universitat de Barcelona)-Vol. 11, Iss: 3, pp 311-320

AbstractA more complete crustal perspective of the northernmost part of the Venezuela Basin is provided by data from an international public database processed with new geomagnetic models (CM4) together with data from aeromagnetic surveys and from a recent marine cruise in areas offshore Puerto Rico and the Dominican Republic. The magnetic anomaly map set off three main domains: the North Atlantic plate, a narrow zone extending from the Dominican Republic to Puerto Rico-Virgin Islands, and the North Caribbean Plate. We focused mainly on the latter, applying the Euler deconvolution algorithm in the Venezuela Basin. Shallow and middle depth sources (located between 2km and 12km) are inferred to be the dominant sources (85%), while deep sources are located mostly in the Venezuela Basin, and scarcely appear in the Beata and Aves Ridges. We performed 2D+1/2 modeling on an eastwest transect, using Bouguer gravity and magnetic anomaly data to derive a more detailed crustal description of the northern part of the Venezuela Basin. The model suggests that in the Caribbean crust, long wavelengths (>200km) are controlled by variations in crustal thickness, whereas the intermediate ones (50-100km) are mainly controlled by variations in their magnetic properties. It also suggests the presence of a local anomalous body located in the east-west transect, between 487km and 560km, displaying a remarkable positive magnetization contrast (0.3 SI) with regard to the rest of the basin. This body shows a slight increase in density (3010kg/m3), and extends from the bottom of the UCL (Underplate Cumulate Layer) to a depth of 7.5km. We correlate it with the volcanic wedge reported by Driscoll and Diebold (1998).

Topics: Bouguer anomaly (56%), Magnetic anomaly (55%)

...read more

Content maybe subject to copyright    Report

Citations
More filters

Journal ArticleDOI
Abstract: The complex tectonic region of NE Caribbean, where Hispaniola and Puerto Rico are located, is bordered by subduction zone with oblique convergence in the north and by incipient subduction zone associated to Muertos Trough in the south. Central Caribbean basin is characterized by the presence of a prominent topographic structure known as Beata Ridge, whose oceanic crustal thickness is unusual. The northern part of Beata Ridge is colliding with the central part of Hispaniola along a transverse NE alignment, which constitutes a morphostructural limit, thus producing the interruption of the Cibao Valley and the divergence of the rivers and basins in opposite directions. The direction of this alignment coincides with the discontinuity that could explain the extreme difference between west and east seismicity of the island. Different studies have provided information about Beata Ridge, mainly about the shallow structure from MCS data. In this work, CARIBE NORTE (2009) wide-angle seismic data are analyzed along a WNW-ESE trending line in the northern flank of Beata Ridge, providing a complete tectonic view about shallow, middle and deep structures. The results show clear tectonic differences between west and east separated by Beata Island. In the Haiti Basin area, sedimentary cover is strongly influenced by the bathymetry and its thickness decreases toward to the island. In this area, the Upper Mantle reaches 20 km deep increasing up to 24 km below the island where the sedimentary cover disappears. To the east, the three seamounts of Beata Ridge provoke the appearance of a structure completely different where sedimentary cover reaches thicknesses of 4 km between seamounts and Moho rises up to 13 km deep. This study has allowed to determine the Moho topography and to characterize seismically the first upper mantle layers along the northern Beata Ridge, which had not been possible with previous MCS data.

13 citations


Cites background from "Lithospheric magnetic mapping of th..."

  • ...north–southward magnetic anomalies (east of the Beata Ridge) can be found distributed over a negative terrace (CATALÁN and MARTÍN DÁVILA 2013)....

    [...]


Journal ArticleDOI
Abstract: In recent years, the Oceanographic and Hydrographic Research Center (part of the General Maritime Directorate of Colombia (DIMAR) has made important efforts to advance research in the field of marine geophysics, in particular, the techniques of geomagnetism, sub-bottom profiling, and side-scan sonar, the first being the most developed at the present time. A method is presented for the acquisition of geomagnetic data in marine environments, as used by DIMAR in the Colombian maritime territory. The development of the geomagnetic method not only offers the opportunity to advance basic scientific knowledge, but it is also of great importance in support of national sovereignty issues. Among other applications, the most representative uses of the geomagnetic method are the location of pipelines and metal plates, detection of buried ordnance, identification of sites of archaeological interest, and the identification and characterization of geological structures. As a result of testing the method, a grid of geomagnetic data was surveyed in an area close to the Island of San Andres in the north-west of the Colombian maritime territory. The survey was prepared with a regional geometric arrangement, the result of which was compared with survey data obtained from the National Oceanic and Atmospheric Administration (NOAA) magnetic data repository and carried out in the same study area. Despite the long time interval between the two surveys, almost 50 years, no significant differences were observed in terms of the analyzed variables. Finally, results show negligible differences between the magnetic data obtained for the years 1970 and 2018 for all the variables measured, such as the inclination, declination, and total magnetic field. These differences may be attributable to a geological component or also to the acquisition and processing methods used in the 1970s.

1 citations


References
More filters

Journal ArticleDOI
TL;DR: GMT allows users to manipulate (x,y,z) data, and generate PostScript illustrations, including simple x-y diagrams, contour maps, color images, and artificially illuminated, perspective, and/or shaded-relief plots using a variety of map projections.
Abstract: Version 31 of the Generic Mapping Tools (GMT) has been released More than 6000 scientists worldwide are currently using this free, public domain collection of UNIX tools that contains programs serving a variety of research functions GMT allows users to manipulate (x,y) and (x,y,z) data, and generate PostScript illustrations, including simple x-y diagrams, contour maps, color images, and artificially illuminated, perspective, and/or shaded-relief plots using a variety of map projections (see Wessel and Smith [1991] and Wessel and Smith [1995], for details) GMT has been installed under UNIX on most types of workstations and both IBM-compatible and Macintosh personal computers

6,358 citations


"Lithospheric magnetic mapping of th..." refers methods in this paper

  • ...ACKNOWLEDGMENTS All figures were done using GMT software (Wessel, 1989; Wessel and Smith, 1998)....

    [...]


Journal ArticleDOI
26 Sep 1997-Science
Abstract: A digital bathymetric map of the oceans with a horizontal resolution of 1 to 12 kilometers was derived by combining available depth soundings with high-resolution marine gravity information from the Geosat and ERS-1 spacecraft. Previous global bathymetric maps lacked features such as the 1600-kilometer-long Foundation Seamounts chain in the South Pacific. This map shows relations among the distributions of depth, sea floor area, and sea floor age that do not fit the predictions of deterministic models of subsidence due to lithosphere cooling but may be explained by a stochastic model in which randomly distributed reheating events warm the lithosphere and raise the ocean floor.

4,200 citations


Journal ArticleDOI
Abstract: Closely spaced satellite altimeter profiles collected during the Geosat Geodetic Mission (-6 km) and the ERS 1 Geodetic Phase (8 km) are easily converted to grids of vertical gravity gradient and gravity anomaly. The long-wavelength radial orbit error is suppressed below the noise level of the altimeter by taking the along-track derivative of each profile. Ascending and descending slope profiles are then interpolated onto separate uniform grids. These four grids are combined to form comparable grids of east and north vertical deflection using an iteration scheme that interpolates data gaps with minimum curvature. The vertical gravity gradient is calculated directly from the derivatives of the vertical deflection grids, while Fourier analysis is required to construct gravity anomalies from the two vertical deflection grids. These techniques are applied to a combination of high-density data from the dense mapping phases of Geosat and ERS 1 along with lower-density but higher-accuracy profiles from their repeat orbit phases. A comparison with shipboard gravity data shows the accuracy of the satellite- derived gravity anomaly is about 4-7 mGal for random ship tracks. The accuracy improves to 3 mGal when the ship track follows a Geosat Exact Repeat Mission track line. These data provide the first view of the ocean floor structures in many remote areas of the Earth. Some applications include inertial navigation, prediction of seafloor depth, planning shipboard surveys, plate tectonics, isostasy of volcanoes and spreading ridges, and petroleum exploration.

1,626 citations


Journal ArticleDOI
Abstract: Magnetic‐survey data in grid form may be interpreted rapidly for source positions and depths by deconvolution using Euler’s homogeneity relation The method employs gradients, either measured or calculated Data need not be pole‐reduced, so that remanence is not an interfering factor Geologic constraints are imposed by use of a structural index Model studies show that the method can locate or outline confined sources, vertical pipes, dikes, and contacts with remarkable accuracy A field example using data from an intensively studied area of onshore Britain shows that the method works well on real data from structurally complex areas and provides a series of depth‐labeled Euler trends which mark magnetic edges, notably faults, with good precision

1,199 citations


"Lithospheric magnetic mapping of th..." refers background or methods in this paper

  • ...We applied the Euler deconvolution algorithm (Thomson, 1982; Reid et al., 1990) to the magnetic anomaly grid (Fig....

    [...]

  • ...We believe this is an intermediate case, best reflected by an index of 2.5 (Reid et al., 1990)....

    [...]


Journal ArticleDOI
TL;DR: A method for rapidly making depth estimates from large amounts of magnetic data is described, based upon Euler’s homogeneity relationship, which can be applied in a wider variety of geologic situations than can model‐dependent techniques.
Abstract: A method for rapidly making depth estimates from large amounts of magnetic data is described The technique is based upon Euler’s homogeneity relationship (hence, the acronym EULDPH) and differs from similar techniques which are currently available in that no basic geologic model is assumed Therefore, EULDPH can be applied in a wider variety of geologic situations than can model‐dependent techniques The price paid for this increased flexibility is a heavier burden on the interpreter Successful interpretation of EULDPH results is partially dependent upon the interpreter’s intuitive understanding of the concept of the equivalent stratum and also partially dependent upon experience with model studies The theoretical basis, the computational algorithm, and applications of EULDPH to model and real data are presented

1,026 citations


"Lithospheric magnetic mapping of th..." refers background or methods in this paper

  • ...We applied the Euler deconvolution algorithm (Thomson, 1982; Reid et al., 1990) to the magnetic anomaly grid (Fig....

    [...]

  • ...The Euler equation relates the magnetic (or gravity) field and its gradients, and the location of the source to the degree of homogeneity N, which may be interpreted as a Structural Index (SI) (Thomson, 1982)....

    [...]