Inversion of scalar magnetic anomalies of regional scale to crustal magnetization anomalies

1985 ◽  
Author(s):  
J. Arkani-Hamed ◽  
D. W. Strangway
Keyword(s):  
Regional Scale ◽  
Magnetic Anomalies ◽  
Crustal Magnetization

Differential reduction‐to‐the‐pole of regional magnetic anomalies

Geophysics ◽  
1988 ◽  
Vol 53 (12) ◽  
pp. 1592-1600 ◽  
Author(s):  
J. Arkani‐Hamed
Keyword(s):  
Frequency Domain ◽  
Regional Scale ◽  
Magnetic Anomalies ◽  
Positive Anomaly ◽  
Low Latitude ◽  
Mean Values ◽  
The North ◽  
Differential Reduction ◽  
Reduction To The Pole ◽  
Spectral Frequency

I present a differential reduction‐to‐the‐pole technique that reduces regional scale magnetic anomalies to the geomagnetic pole, while taking into account the variations in the direction of the geomagnetic field and that of the magnetization of the crust over the region. The technique is developed in the spectral frequency domain as an inverse problem solved iteratively using a perturbation method. I regard the variations in the directions as finite perturbations about the mean values of the directions over the region and evaluate the nonlinear coupling terms due to these perturbations in the space domain at each iteration before transforming them into the spectral frequency domain. The technique is applied to the magnetic anomalies of three semiinfinite prisms, which are inductively magnetized and located at high, mid, and low latitudes in a region where the inclination of the ambient field changes from 10 to 90 degrees and its declination changes from −30 to +30 degrees. The differential reduction to the pole shifts the positive anomaly of the low‐latitude prism toward the north more than it shifts that of the mid‐latitude prism, which in turn is shifted northward more than that of the high‐latitude prism. The reduction also suppresses the negative lobes to the north of the mid and low‐latitude prisms and moves the positive anomalies to points directly over the prisms. I also apply the technique to the marine magnetic anomalies off the east coast of Canada. The positive magnetic anomalies in the southern part of the area are displaced northward by about 30 km, whereas those in the northern part are not moved significantly.

Crustal magnetization in the South Atlantic from inversion of magnetic anomalies

1989 ◽  
Vol 94 (B11) ◽  
pp. 15463-15480 ◽  
Author(s):  
Nancy A. Wittpenn ◽  
Christopher G. A. Harrison ◽  
David W. Handschumacher
Keyword(s):  
Magnetic Anomalies ◽  
South Atlantic ◽  
The South ◽  
Crustal Magnetization

Koreans across the Sea: Migration of Laborers to the Metropole, 1910–1937

2019 ◽  
pp. 161-200
Author(s):  
Mikwi Cho
Keyword(s):  
Capital Accumulation ◽  
Regional Scale ◽  
Living Conditions ◽  
Colonial Period ◽  
Global City ◽  
Japanese Empire ◽  
Chain Migration ◽  
Free Mobility

This paper is concerned with Korean farmers who were transformed into laborers during the Korean colonial period and migrated to Japan to enhance their living conditions. The author’s research adopts a regional scale to its investigation in which the emergence of Osaka as a global city attracted Koreans seeking economic betterment. The paper shows that, despite an initial claim to permit the free mobility of Koreans, the Japanese empire came to control this mobility depending on political, social, and economic circumstances of Japan and Korea. For Koreans, notwithstanding poverty being a primary trigger for the abandonment of their homes, the paper argues that their migration was facilitated by chain migration and they saw Japan as a resolution to their economic hardships in the process of capital accumulation by the empire.

Zooplankton community responses to regional-scale weather variability: a synoptic climatology approach

2015 ◽  
Vol 62 (3) ◽  
pp. 189-198 ◽  
Author(s):  
AL Primo ◽  
DG Kimmel ◽  
SC Marques ◽  
F Martinho ◽  
UM Azeiteiro ◽  
...  
Keyword(s):  
Regional Scale ◽  
Zooplankton Community ◽  
Synoptic Climatology ◽  
Community Responses ◽  
Weather Variability
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