Extent of the South Pacific Superswell | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Extent of the South Pacific Superswell

Type de publication:

Journal Article

Source:

Journal of Geophysical Research-Solid Earth, Volume 110, Ticket B9, p.B09408 ; doi : 10.1029/2004JB003465 (2005)

ISBN:

0148-0227

Numéro d'accès:

ISI:000232182100001

URL:

http://www.agu.org/

Mots-clés:

MANTLE; BATHYMETRY; HOTSPOT; GRAVITY; SWELLS; DEPTH

Résumé:

The South Pacific Superswell is known as a broad area beneath French Polynesia characterized by numerous volcanic chains and very shallow seafloor compared to the depth predicted for its age by classical seafloor subsidence models. So far, its exact extent has not yet been established. Thanks to better bathymetric coverage and a specially adapted filtering method, we present here a new, complete, and precise mapping of the superswell. We show that the superswell covers a region broader than previously expected. It extends between latitudes 10 degrees N and 30 degrees S and longitudes 130 degrees W and 160 degrees W and has a maximum amplitude of 680 m. It is composed of two branches that display different characteristics when compared to other geophysical observations. Under the southern branch a dip in the geoid is observed which could be linked to upwelling in a convective mantle where the low-velocity zone is located immediately below the lithosphere as indicated by tomography models. Under the northern branch, there is a 12 m high in the geoid surface anomaly that may be explained by isostatic compensation of a mass deficiency located in the mantle at 300 km depth. The northern branch could also be related to another superplume that is now going down but which was rising up 30-90 m.y. ago, when it initiated the secondary plumes which created the Line Islands.

Notes:

J. Geophys. Res.-Solid EarthISI Document Delivery No.: 968SHTimes Cited: 4Cited Reference Count: 50Cited References:ADAM C, 2005, GEOCHEM GEOPHY GEOSY, V6BERCOVICI D, 1997, PHYS EARTH PLANET IN, V101, P119BONNEVILLE A, 2001, 2 U POL FRANCBONNEVILLE A, 2002, GEOLOGY, P1023COCHRAN JR, 1986, GEOPHYS J ROY ASTRON, V87, P421CROUGH ST, 1978, GEOPHYS J ROY ASTRON, V55, P451CROUGH ST, 1983, ANNU REV EARTH PL SC, V11, P165DAVAILLE A, 1999, NATURE, V402, P756DESONIE DL, 1993, J GEOPHYS RES-SOL EA, V98, P17649DIRAISON C, 1991, THESIS U BRETAGNE OCDUNCAN RA, 1976, J VOLCANOL GEOTH RES, V1, P197EKSTROM G, 1998, NATURE, V394, P168GABORET C, 2002, THESIS I PHYS GLOBEGOODWILLIE AM, 1993, EARTH PLANET SC LETT, V118, P311GRAND SP, 1997, GSA TODAY, V7, P1HAGER BH, 1984, J GEOPHYS RES, V89, P6003HAGER BH, 1989, MANTLE CONVECTION, P657HILLIER JK, 2004, J GEOPHYS RES-SOL EA, V109JELLINEK AM, 2002, GEOPHYS RES LETT, V29LEBARS M, 2004, J GEOPHYS RES-SOL EA, V109LEMOINE F, 1998, NASATP1998206861LEVITT DA, 1996, EARTH PLANET SC LETT, V139, P1MALEVSKY AV, 1993, GEOPHYS RES LETT, V20, P383MAMMERICKX J, 1980, GEOL SOC AM BULL, V91, P263MCNUTT MK, 1987, GEOPHYS MONOGR SER, V43, P25MCNUTT MK, 1990, SCIENCE, V248, P969MCNUTT MK, 1996, GEOPHYS RES LETT, V23, P3397MCNUTT MK, 1998, REV GEOPHYS, V36, P211MONTAGNER JP, 2002, EARTH PLANET SC LETT, V632, P1MORGAN JP, 1995, J GEOPHYS RES-SOLID, V100, P8045MULLER D, 1997, J GEOPHYS RES, V102, P3211NORRIS RA, 1969, J GEOPHYS RES, V74, P650OLSON P, 1993, J GEOPHYS RES-SOLID, V98, P6829PARSONS B, 1977, J GEOPHYS RES, V82, P803RABINOWICZ M, 1993, J GEOPHYS RES-SOLID, V98, P7851ROMANOWICZ B, 2002, SCIENCE, V296, P513SANDWELL DT, 1995, J GEOPHYS RES-SOL EA, V100, P15087SANDWELL DT, 1997, J GEOPHYS RES-SOL EA, V102, P10039SCHLANGER S, 1984, J GEOPHYS RES, V89, P11216SCHUBERT G, 2004, PHYS EARTH PLANET IN, V146, P147SICHOIX L, 1998, J GEOPHYS RES-SOL EA, V103, P27123SMITH WHF, 1997, SCIENCE, V277, P1956STEIN CA, 1992, NATURE, V359, P123STOFFERS P, 1990, MAR GEOL, V95, P51SU WJ, 1992, EOS T AGU S, V73, P201TALANDIER J, 1987, GEOPHYS J ROY ASTRON, V88, P499VANWYKHOUSE R, 1973, TR233 NAT OC OFFVIDAL V, 2004, J GEOPHYS RES-SOL EA, V109WATTS AB, 1985, GEOPHYS J ROY ASTRON, V83, P263WESSEL P, 1991, EOS T AM GEOPHYS UN, V72, P445B09408