Magnetic anomalies in the western part of the North Anatolian Fault Zone and their implications for active fault structure.

Işıkara, A. M.; Honkura, Yoshimori; Watanabe, Nobuo; Orbay, Naci; Kolçak, D.; Ohshiman, N.; Gündoğdu, Oğuz; Tanaka, Haruo

doi:10.5636/jgg.37.541

Cited by 19 publications

(15 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ground magnetic survey along the North Anatolian fault defined a number of coherent magnetic anomalies supposed to be caused by sheet-shaped sources (ISIKARA et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Ground Magnetic Anomalies in the Tanna Fault and Their Implications.

Okubo

Mizugaki

Kanaya

1991

J. geomagn. geoelec

View full text Add to dashboard Cite

The Tanna fault is a left lateral fault extending in the middle of the Izu Peninsula. We carried out a detailed ground magnetic survey at a grid spacing of 50 to 150 m along the Tanna fault and constructed a magnetic model based on the ground survey with the help of drilling data in the Tanna basin and measurement of rock magnetism.Total intensity distribution obtained by the ground magnetic survey represents a distinguished contrast forming relative magnetic highs in the west to the fault and lows in the east. The Tanna fault is a remarkable border terminating magnetic highs.Drillings revealed that formations filling the Tanna basin are mainly the middle Pleistocene Taga volcanics which possess high susceptibility as a whole. A recent work suggests that the Taga volcanics were produced in normal polarity and had strong remanent magnetization. Therefore, remanent magnetization is inferred to be dominant in the total magnetization.The magnetic contrast forms almost a north-south trend throughout the study area. The magnetic modeling using E-W profiles delineated strong normally magnetized sources of 6 A/ m confined to the west to the fault. Three drillings indicated that the east formations to the fault were wholly disintegrated and the west formations, by contrast, included fresh lavas. These evidences suggest that the major cause of magnetic contrast is not the difference of geologic unit but instead the weakened remanent magnetization in the east adjacent area to the fault.Seismic reflection and shallow drillings indicate the possibility of existence of shallow wrench fault. Bending usuallly appears along a strike slip and actually several basins such as Tanna basin and the Tashiro basin exist along the fault, and some magnetic lows are supposed to be caused by sinking of volcanic layer or pull-apart movements. The striking magnetic discontinuity, on the other hand, implies that the fault surface been displaced ever since Pleistocene has always been the known Tanna fault.In conclusion, the cause of relative magnetic lows in the east to the fault is responsible for effects of, either remanent magnetization reduced, and sinking and truncating of magnetic sources deformed, by the fault activities.

show abstract

“…The ground magnetic survey along the North Anatolian fault defined a number of coherent magnetic anomalies supposed to be caused by sheet-shaped sources (ISIKARA et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Ground Magnetic Anomalies in the Tanna Fault and Their Implications.

Okubo

Mizugaki

Kanaya

1991

J. geomagn. geoelec

View full text Add to dashboard Cite

show abstract

“…The magnetic anomalies found near the active fault constituting the southern branch could be well interpreted in terms of a dike-like structure, which in turn provided information on the surface extension of the fault plane as well as its dip angle I IKARA et al, 1985). Folding may also disturb the subsurface magnetic structure and yield a magnetic anomaly to be observed at the Earth's surface.…”

Section: Introductionmentioning

confidence: 88%

Magnetic Anomalies Related to Active Folds in the North Anatolian Fault Zone.

Tunçer

Honkura²,

Oshiman

et al. 1991

J. geomagn. geoelec

Self Cite

View full text Add to dashboard Cite

“…We can apply a dike model, as used by ISIKARA et al (1985), to the magnetic anomaly observed along the line A. Figure 10 shows the result of inversion for a dike model.…”

Section: Interpretation Of the Observed Anomaliesmentioning

confidence: 99%

Electric and magnetic anomalies at the Atotsugawa fault and their implications for fault activity.

Ohshiman

Honkura²,

Kuge³

et al. 1987

J. geomagn. geoelec

Self Cite

View full text Add to dashboard Cite

Observations of the geomagnetic total intensity, electric self-potential and surface resistivity were carried out at the Atotsugawa fault, a 60 km long active fault of strike-slip type located in central Japan, in order to investigate the active fault structure and fault activity from electric and magnetic aspects. Notable anomalies were found along a measurement line selected in the central segment of the Atotsugawa fault. The anomalies are summarized as follows. The surface resistivity, as derived from VLF-MT, of the zone bounded on the north by one fault line and on the south by another is lower than that outside the zone. A very local anomaly in self-potential exists at the northern fault line which constitutes the northern boundary of the low resistivity zone. Inside this low resistivity zone exists a somewhat more resistive body. It should be highly magnetized as deduced from a magnetic anomaly amounting to about 600 nT which was observed over the resistive body . The low resistivity zone seems to correspond to the fractured zone bounded by the two fault lines, and the northern one would be more active as implied by the self-potential anomaly which can be interpreted in terms of the electrokinetic effect associated with groundwater flow along the fault plane.

show abstract

Magnetic anomalies in the western part of the North Anatolian Fault Zone and their implications for active fault structure.

Cited by 19 publications

References 5 publications

Ground Magnetic Anomalies in the Tanna Fault and Their Implications.

Ground Magnetic Anomalies in the Tanna Fault and Their Implications.

Magnetic Anomalies Related to Active Folds in the North Anatolian Fault Zone.

Electric and magnetic anomalies at the Atotsugawa fault and their implications for fault activity.

Contact Info

Product

Resources

About