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| Titel |
The Caribbean conundrum of Holocene sea level. |
| VerfasserIn |
Luke Jackson, Jon Mound |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090662
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| Publikation (Nr.) |
 EGU/EGU2014-4915.pdf |
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| Zusammenfassung |
| In the tropics, pre-historic sea-level curve reconstruction is often problematic because it relies
upon sea-level indicators whose vertical relationship to the sea surface is poorly constrained.
In the Caribbean, fossil corals, mangrove peats and shell material dominate the pre-historic
indicator record. The common approach to reconstruction involves the use of modern
analogues to these indicators to establish a fixed vertical habitable range. The aim of these
reconstructions is to find spatial variability in the Holocene sea level in an area gradually
subsiding (< 1.2 mm yr-1) due the water loading following the deglaciation of the Laurentide
ice sheet.
We construct two catalogues: one of published Holocene sea-level indicators and the
other of published, modern growth rates, abundance and coverage of mangrove and coral
species for different depths. We use the first catalogue to calibrate 14C ages to give a
probabilistic age range for each indicator. We use the second catalogue to define a depth
probability distribution function (pdf) for mangroves and each coral species. The Holocene
indicators are grouped into 12 sub-regions around the Caribbean. For each sub-region we
apply our sea-level reconstruction, which involves stepping a fixed-length time window
through time and calculating the position (and rate) of sea-level (change) using
a thousand realisations of the time/depth pdfs to define an envelope of probable
solutions.
We find that the sub-regional relative sea-level curves display spatio-temporal variability
including a south-east to north-west 1500 year lag in the arrival of Holocene sea level to
that of the present day. We demonstrate that these variations are primarily due to
glacial-isostatic-adjustment induced sea-level change and that sub-regional variations (where
sufficient data exists) are due to local uplift variability. |
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