The University of Southampton
University of Southampton Institutional Repository

Oceanic crust and Moho of the Pacific Plate in the eastern Ogasawara Plateau region

Oceanic crust and Moho of the Pacific Plate in the eastern Ogasawara Plateau region
Oceanic crust and Moho of the Pacific Plate in the eastern Ogasawara Plateau region
To show the structure of oceanic crust and Moho around the eastern Ogasawara Plateau, we have analyzed industry-standard two-dimensional multichannel seismic reflection data. To obtain improved velocity models, phase information of seismic signals was used for velocity analysis and velocity models for oceanic crust above Moho were determined. We apply this velocity analysis technique to seismic reflection data around the eastern Ogasawara Plateau, with the result of clear images of structures within oceanic crust and Moho. South of the Ogasawara Plateau, Moho deepens proximal to the Plateau. Moho distal to the Plateau is ca 7 km below sea floor (bsf), whereas it is ca 10 km bsf near the Plateau. The characters of oceanic crust and Moho differ significantly north and south of the Plateau. To the north, the structure of oceanic crust is ambiguous, the sea floor is shallower and less smooth, and Moho is discontinuous. To the south, structures within oceanic crust and Moho are imaged clearly, and the sea floor is deeper. A strong Moho reflection south of the Plateau might represent a sharp boundary between layered gabbro and peridotite. However, discontinuous Moho reflections north of the Plateau might represent rough topography because of intensive magmatism or a gradual downward increase in velocity within a thick Moho transition zone. A fracture zone north of the Plateau also appears to separate oceanic crust and Moho of different characters, suggesting vigorous magmatism between the Plateau and the fracture zone, and that the Ogasawara Plateau and the fracture zone influenced the genesis of oceanic crust and upper mantle. Differences in acoustic characteristics to the north and south of the Plateau are apparent in profiles illuminated by seismic attributes.
magmatic activities, Moho, oceanic crust, Ogasawara Plateau, seismic attributes, seismic velocity
1038-4871
361-373
Tsuji, T.
6dc740d8-07e2-4a72-99f6-08987d688c77
Nakamura, Y.
e0f3fa39-599e-4a46-b7db-74c65ac2c66d
Tokuyama, H.
61c84b89-7a69-4de7-9f0e-28c9e2383960
Coffin, M.F.
b8285650-5efd-4129-ae91-1cf3f5911e89
Koda, K.
0094a764-11c9-4338-b63d-3b967ebc577b
Tsuji, T.
6dc740d8-07e2-4a72-99f6-08987d688c77
Nakamura, Y.
e0f3fa39-599e-4a46-b7db-74c65ac2c66d
Tokuyama, H.
61c84b89-7a69-4de7-9f0e-28c9e2383960
Coffin, M.F.
b8285650-5efd-4129-ae91-1cf3f5911e89
Koda, K.
0094a764-11c9-4338-b63d-3b967ebc577b

Tsuji, T., Nakamura, Y., Tokuyama, H., Coffin, M.F. and Koda, K. (2007) Oceanic crust and Moho of the Pacific Plate in the eastern Ogasawara Plateau region. The Island Arc, 16 (3), 361-373. (doi:10.1111/j.1440-1738.2007.00589.x).

Record type: Article

Abstract

To show the structure of oceanic crust and Moho around the eastern Ogasawara Plateau, we have analyzed industry-standard two-dimensional multichannel seismic reflection data. To obtain improved velocity models, phase information of seismic signals was used for velocity analysis and velocity models for oceanic crust above Moho were determined. We apply this velocity analysis technique to seismic reflection data around the eastern Ogasawara Plateau, with the result of clear images of structures within oceanic crust and Moho. South of the Ogasawara Plateau, Moho deepens proximal to the Plateau. Moho distal to the Plateau is ca 7 km below sea floor (bsf), whereas it is ca 10 km bsf near the Plateau. The characters of oceanic crust and Moho differ significantly north and south of the Plateau. To the north, the structure of oceanic crust is ambiguous, the sea floor is shallower and less smooth, and Moho is discontinuous. To the south, structures within oceanic crust and Moho are imaged clearly, and the sea floor is deeper. A strong Moho reflection south of the Plateau might represent a sharp boundary between layered gabbro and peridotite. However, discontinuous Moho reflections north of the Plateau might represent rough topography because of intensive magmatism or a gradual downward increase in velocity within a thick Moho transition zone. A fracture zone north of the Plateau also appears to separate oceanic crust and Moho of different characters, suggesting vigorous magmatism between the Plateau and the fracture zone, and that the Ogasawara Plateau and the fracture zone influenced the genesis of oceanic crust and upper mantle. Differences in acoustic characteristics to the north and south of the Plateau are apparent in profiles illuminated by seismic attributes.

This record has no associated files available for download.

More information

Published date: September 2007
Keywords: magmatic activities, Moho, oceanic crust, Ogasawara Plateau, seismic attributes, seismic velocity

Identifiers

Local EPrints ID: 52472
URI: http://eprints.soton.ac.uk/id/eprint/52472
ISSN: 1038-4871
PURE UUID: 4913ef36-6deb-4b0e-ac06-835f134bd79c

Catalogue record

Date deposited: 01 Jul 2008
Last modified: 08 Jan 2022 10:04

Export record

Altmetrics

Contributors

Author: T. Tsuji
Author: Y. Nakamura
Author: H. Tokuyama
Author: M.F. Coffin
Author: K. Koda

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×