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Mid-Pacific microatolls record sea-level stability over the past 5000 yr

Journal Article


Abstract


  • There has been geographical variation in sea level since rapid postglacial melting of polar ice ceased ~6 k.y. ago, reflecting isostatic adjustments of Earth and ocean surfaces to past (and ongoing) redistribution of ice and water loads. A new data set of over 100 fossil microatolls from Christmas (Kiritimati) Island provides a Holocene sea-level record of unparalleled continuity. Living reef-flat corals grow up to a low-tide level. Adjacent fossil microatolls, long-lived Porites corals up to several meters in diameter, occur at similar elevations (±0.1 m), and extensive fossil microatolls in the island interior are at consistent elevations within each population. Collectively, they comprise an almost continuous sequence spanning the past 5 k.y., indicating that, locally, sea level has been within 0.25 m of its present position, and precluding global sea-level oscillations of one or more meters inferred from less stable locations, or using other sea-level indicators. This mid-Pacific atoll is tectonically stable and far from former ice sheets. The precisely surveyed and radiometrically dated microatolls indicate that sea level has not experienced significant oscillations, in accordance with geophysical modeling, which implies that the eustatic contribution from past ice melt and the isostatic adjustment of the ocean floor to loading largely cancel each other at this site. © 2012 Geological Society of America.

Publication Date


  • 2012

Citation


  • Woodroffe, C. D., McGregor, H. V., Lambeck, K., Smithers, S. G. & Fink, D. (2012). Mid-Pacific microatolls record sea-level stability over the past 5000 yr. Geology (Boulder), 40 (10), 951-954.

Scopus Eid


  • 2-s2.0-84868683185

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4709

Has Global Citation Frequency


Number Of Pages


  • 3

Start Page


  • 951

End Page


  • 954

Volume


  • 40

Issue


  • 10

Place Of Publication


  • United States

Abstract


  • There has been geographical variation in sea level since rapid postglacial melting of polar ice ceased ~6 k.y. ago, reflecting isostatic adjustments of Earth and ocean surfaces to past (and ongoing) redistribution of ice and water loads. A new data set of over 100 fossil microatolls from Christmas (Kiritimati) Island provides a Holocene sea-level record of unparalleled continuity. Living reef-flat corals grow up to a low-tide level. Adjacent fossil microatolls, long-lived Porites corals up to several meters in diameter, occur at similar elevations (±0.1 m), and extensive fossil microatolls in the island interior are at consistent elevations within each population. Collectively, they comprise an almost continuous sequence spanning the past 5 k.y., indicating that, locally, sea level has been within 0.25 m of its present position, and precluding global sea-level oscillations of one or more meters inferred from less stable locations, or using other sea-level indicators. This mid-Pacific atoll is tectonically stable and far from former ice sheets. The precisely surveyed and radiometrically dated microatolls indicate that sea level has not experienced significant oscillations, in accordance with geophysical modeling, which implies that the eustatic contribution from past ice melt and the isostatic adjustment of the ocean floor to loading largely cancel each other at this site. © 2012 Geological Society of America.

Publication Date


  • 2012

Citation


  • Woodroffe, C. D., McGregor, H. V., Lambeck, K., Smithers, S. G. & Fink, D. (2012). Mid-Pacific microatolls record sea-level stability over the past 5000 yr. Geology (Boulder), 40 (10), 951-954.

Scopus Eid


  • 2-s2.0-84868683185

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4709

Has Global Citation Frequency


Number Of Pages


  • 3

Start Page


  • 951

End Page


  • 954

Volume


  • 40

Issue


  • 10

Place Of Publication


  • United States