Topography and a magnetic analysis of an area south-east of the Azores (36°N, 23°W)

Autor: Twigt, W., Slootweg, A. P., Collette, B. J.
Zdroj: Marine Geophysical Researches; August 1979, Vol. 4 Issue: 1 p91-104, 14p
Abstrakt: A detailed survey of a 1°×1°-square of seafloor 100 miles south-east of the Azores shows a strong correlation between directions of regional topographic and magnetic lineations. The area is dissected by the East Azores Fracture Zone at 36°55'N, identified as the active Eurasian-African plate boundary, and by another large, non-active fracture zone at 36°10'N. Both fracture zones strike 265° and are accompanied by large amplitude magnetic anomalies. The general strike in the area in between is 000°–015°. The skewing effect at this magnetic latitude is very sensitive to variations in strike of the magnetic contrasts. This effect was eliminated by a non-linear transformation which also gives the positions of magnetic contrasts. Some N-S contrasts were identified as sea floor spreading polarity contrasts (anomalies 31 and 32). Weak contrasts could be identified as topographic effects and gave a magnetization intensity of 5 A m-1. The identified sea floor spreading anomalies to both sides of the fracture zone at 36°10'N agree very well, also quantatively, with a three-dimensional model for the fracture zone anomalies. This model describes the non-linear anomalies as end effects of the magnetic layer which is divided in blocks of alternating polarity.
Databáze: Supplemental Index
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