Bathymetry and marine geophysical observations of the Ayu Trough, Southern Philippine Sea: Implications for crustal extension and structure SCOPUS KCI

Title
Bathymetry and marine geophysical observations of the Ayu Trough, Southern Philippine Sea: Implications for crustal extension and structure
Author(s)
Jung, M.-S.; Lee, S.-M.
Alternative Author(s)
정미숙; 이상묵
Publication Year
2002-09
Abstract
The Ayu Trough, located in the southern end of the Philippine Sea, represents a divergent boundary between the Philippine Sea and the Caroline plates. A detailed geophysical survey was carried out in the Ayu Trough by R/V Onnuri. Topographically, the Ayu Trough resembles an slow spreading ridge. The trough can be divided into three sections: the south (0°-1°30'N), middle (1°30'-4°N), and north (4°-6°30'N). The seafloor in the middle section is characterized by features asymmetric with respect to the axis. These features were probably produced by NW-SE and NNW-SSE extensions and seem to support the argument that the opening of the Ayu Trough occurred in an oblique fashion. Farther south, a long transform fault but with a short offset defines the boundary between middle and southern sections. The axial depth increases a stepwise to the south of 1°30'N. A clear difference can be seen between the southern and middle sections with the latter exhibiting much higher mantle Bouguer anomaly values in the axial region. The anomaly indicates that the axial crust perhaps experienced a much higher degree of extension in the middle than in the southern section. The analyses of magnetic field data reveal that the region beyond 100 km exhibits considerable variations, whereas the magnetic anomalies within 100 km from the trough axis are very much subdued. This observation suggests that the opening of the Ayu Trough involved an initial stage of rifting of existing volcanic arcs, followed by production of new seafloor.
ISSN
1598-141X
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/5758
DOI
10.4217/OPR.2002.24.3.179
Bibliographic Citation
Ocean and Polar Research, v.24, no.3, pp.179 - 187, 2002
Publisher
Korea Ocean Research and Development Institute
Keywords
Magnetic equator; Oblique fashion; Slow-spreading ridge
Type
Article
Language
Korean
Document Type
Article
Publisher
Korea Ocean Research and Development Institute
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