Linear feature analysis for aeromagnetic data

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. L61-L67 ◽  
Author(s):  
R. O. Hansen ◽  
Eduard deRidder
Keyword(s):  
New York ◽  
Principal Curvature ◽  
New York State ◽  
Synthetic Data ◽  
Depth Estimation ◽  
Structural Features ◽  
Horizontal Gradient ◽  
Aeromagnetic Data ◽  
Linear Feature ◽  
Total Gradient

This paper presents a new approach to detecting and two approaches to displaying lineaments associated with high-angle magnetic contacts, based on analysis of the curvature of the total horizontal gradient of the total magnetic field reduced to the pole. The first display is a contour or color plot of minus the principal curvature of largest absolute value. The second is a point plot of the local maxima of minus the largest principal curvature in regions where this curvature is negative. The paper also develops a depth-estimation technique for magnetic contacts based on the ratio of the curvature of the total gradient to the total gradient itself. Tests on synthetic data yield excellent results in detecting and delineating magnetic contact edges, and reasonable performance in producing depth estimates for the magnetic contacts. Results obtained using aeromagnetic data from the Finger Lakes region of New York State show good correlation with known structural features.

scholarly journals Structural features derived from a Multiscale Analysis and 2.75D Modelling of Aeromagnetic Data over the Pitoa-Figuil Area (Northern Cameroon)

2020 ◽  
Author(s):  
Voltaire Souga Kassia ◽  
Theophile Ndougsa-Mbarga ◽  
Arsène Meying ◽  
Jean Daniel Ngoh ◽  
Steve Ngoa Embeng
Keyword(s):  
Multiscale Analysis ◽  
Structural Features ◽  
Magnetic Data ◽  
Horizontal Gradient ◽  
Aeromagnetic Data ◽  
Near Surface ◽  
Subsurface Structures ◽  
Northern Cameroon ◽  
Processing Techniques ◽  
Geological Formations

Abstract. In the Pitoa-Figuil area (Northern Cameroon), an interpretation of aeromagnetic data was conducted. The aim of this investigation was first to emphasize lineaments hidden under geological formations and secondly to propose two 2.75D models of the subsurface structures. Different magnetic data processing techniques were used, notably horizontal gradient magnitude, analytic signal, and Euler deconvolution. These techniques in combination with the 2.75D modelling to the aeromagnetic anomaly reduced to the equator permit to understand the stratification of the deep and near surface structures, which are sources of the observed anomalies. We managed to put in evidence and characterize 18 faults and some intrusive bodies. According to Euler's solutions, anomaly sources go up to a depth of 5.3 km.

scholarly journals Evidence of Major Structural Features over the Pan-African Domain in the Bertoua-Mbangue Area (East Cameroon) from a Multiscale Approach of Modeling and Interpretation of Aeromagnetic Data

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Owono Amougou Olivier Ulrich Igor ◽  
Ndougsa Mbarga Theophile ◽  
Meying Arsène ◽  
Assembe Stephane Patrick ◽  
Ngoh Jean Daniel ◽  
...  
Keyword(s):  
High Amplitude ◽  
Structural Features ◽  
Short Wave ◽  
The Other ◽  
Horizontal Gradient ◽  
Multiscale Approach ◽  
Magnetic Intensity ◽  
Aeromagnetic Data ◽  
Pan African ◽  
Basement Structures

The aim of this study is to investigate crustal structures from East Cameroon, using aeromagnetic data. The modeling of aeromagnetic data is conducted using the Oasis Montaj 8.0 software. The total magnetic intensity map reduced to the equator (RTE-TMI) shows important anomalies features, namely, the Northern East magnetic anomalies of high amplitude, the Southwest where very low values of the magnetic intensity were observed, and a corridor with negative values relatively high, separating the anomalies. The horizontal gradient map shows on the one hand brittle and folded structures carried out in the area of study and on the other hand various rectilinear, narrow, and short-wave anomalies that can be classified as a family of little faults. The maxima observed on the RTE-TMI maps are correlated to intrabasement contacts; and the map derived from Euler’s solutions permitted to evaluate the depth of the geological accidents observed from the other filters. This map also reveals new faults with a depth greater than 5000 m. The lineaments identified in the Southwestern part could be linked to the Pan-African orogeny and seem to correspond to deep-seated basement structures, which are referred to the tectonic boundary between Congo Craton and the Pan-African orogeny belt. A 23/4-D modeling confirmed the observations derived from the RTE-TMI and HGM maps analyses. It shows intrusive bodies composed of gneiss and porphyroid granite and some domes with their roof situated at various depths not exceeding 1800 m from the surface. The structural map of the study area shows the trending of the structural features observed, namely, NE-SW, NW-SE, ENE-WSW, and WNW-ESE, respectively, while the E-W and N-S are secondary orientation of the observed tectonic evidence. Moreover, circular anomalies observed over the area are assimilated to intrusions of high magnetic materials or to granitic domes.

scholarly journals Structural Elements and Neotectonics of Prince Edward County, Southern Ontario

2007 ◽  
Vol 47 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Gail H. McFall
Keyword(s):  
New York ◽  
New York State ◽  
Lake Ontario ◽  
Structural Features ◽  
Structural Elements ◽  
Southern Ontario ◽  
York State ◽  
Salmon River ◽  
Middle Ordovician ◽  
Prince Edward County

ABSTRACT The seismically active Clarendon-Linden Fault of western New York State appears to connect with the Salmon River Fault and possibly with the Picton Fault, both of which cut through Prince Edward County, southern Ontario. Bedrock exposures display a variety of structural features including faults, fractures, and pop-ups which indicate that the region has been subjected to repeated tectonism since the Middle Ordovician. Thus, despite the general perception that Prince Edward County and the rest of the Lake Ontario region is one of low seismic potential, geological and geophysical data suggest otherwise.

Cultural Competence Needed to Distinguish Disorder from Difference: Beyond Kumbaya

2015 ◽  
Vol 22 (2) ◽  
pp. 64-76 ◽  
Author(s):  
Catherine J. Crowley ◽  
Kristin Guest ◽  
Kenay Sudler
Keyword(s):  
New York ◽  
New York City ◽  
Public Schools ◽  
Cultural Competence ◽  
York City ◽  
Cultural Sensitivity ◽  
Graduate Program ◽  
Language Disorder ◽  
New York State ◽  
Deep Understanding

What does it mean to have true cultural competence as an speech-language pathologist (SLP)? In some areas of practice it may be enough to develop a perspective that values the expectations and identity of our clients and see them as partners in the therapeutic process. But when clinicians are asked to distinguish a language difference from a language disorder, cultural sensitivity is not enough. Rather, in these cases, cultural competence requires knowledge and skills in gathering data about a student's cultural and linguistic background and analyzing the student's language samples from that perspective. This article describes one American Speech-Language-Hearing Association (ASHA)-accredited graduate program in speech-language pathology and its approach to putting students on the path to becoming culturally competent SLPs, including challenges faced along the way. At Teachers College, Columbia University (TC) the program infuses knowledge of bilingualism and multiculturalism throughout the curriculum and offers bilingual students the opportunity to receive New York State certification as bilingual clinicians. Graduate students must demonstrate a deep understanding of the grammar of Standard American English and other varieties of English particularly those spoken in and around New York City. Two recent graduates of this graduate program contribute their perspectives on continuing to develop cultural competence while working with diverse students in New York City public schools.

Cryptosporidiosis From Water Park Tapering Off in New York State

2005 ◽  
Vol 38 (20) ◽  
pp. 8
Author(s):  
MICHELE G. SULLIVAN
Keyword(s):  
New York ◽  
New York State ◽  
York State

New York State Assisted Outpatient Treatment Program Evaluation

2009 ◽  
Author(s):  
Marvin S. Swartz ◽  
Jeffrey W. Swanson ◽  
Henry J. Steadman ◽  
Pamela Clark Robbins ◽  
John Monahan
Keyword(s):  
New York ◽  
Program Evaluation ◽  
Treatment Program ◽  
Outpatient Treatment ◽  
New York State ◽  
York State ◽  
Assisted Outpatient Treatment
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