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| Titel |
New chronology for Red Sea sea-level record reveals phase relationship between changes in polar climate and ice volume |
| VerfasserIn |
K. M. Grant, E. J. Rohling, C. Bronk Ramsey, M. Bar-Matthews, C. Satow, M. Medina-Elizalde, A. P. Roberts |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250061115
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| Zusammenfassung |
| Understanding process relationships within the climate system requires records of individual
climate components with excellent time control. Continuous records of ice volume, a key
component in the climate system, now exist from several sea level reconstruction methods.
However, none of these have sufficient time control to allow detailed comparison with other
climate records, or systematic evaluation of rates of change. Here we present a tightly
controlled U-series chronology for the high-resolution Red Sea sea-level record through the
last 150,000 years. This chronology is based on strong signal similarity between δ18O records
from the Red Sea and the nearby eastern Mediterranean. We constrain the chronology
of the latter with U-series dating of Soreq Cave (Israel) speleothems and dated
volcanic ash horizons. The resultant sea level chronology is validated using the
timing of major sea level transitions in a global compilation of coral data, and for
the first time characterises the timing of ice volume variability throughout the last
150,000 years on millennial timescales. We then use a probabilistic assessment of our
new sea-level record to show where variations in global ice volume significantly
agree (within the 67 and 85% probability range) with variations in Antarctic and/or
Greenland climate. Next, by performing a series of lagged correlations and cross-spectral
phase analyses, we show that polar climate and ice volume are strongly coupled
within a relatively fast (generally 100-200 years) response time. Most significantly,
rates of change in polar climate and ice volume appear to be directly in phase, and
rates of sea-level rise during six major deglaciations are at least 2 m per century. |
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