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Titel |
Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr |
VerfasserIn |
E. M. Gayo, C. Latorre, C. M. Santoro, A. Maldonado, R. Pol-Holz |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 8, no. 1 ; Nr. 8, no. 1 (2012-02-21), S.287-306 |
Datensatznummer |
250005374
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Publikation (Nr.) |
copernicus.org/cp-8-287-2012.pdf |
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Zusammenfassung |
Paleoclimate reconstructions reveal that Earth system has
experienced sub-millennial scale climate changes over the past two millennia
in response to internal/external forcing. Although sub-millennial
hydroclimate fluctuations have been detected in the central Andes during
this interval, the timing, magnitude, extent and direction of change of
these events remain poorly defined. Here, we present a reconstruction of
hydroclimate variations on the Pacific slope of the central Andes based on
exceptionally well-preserved plant macrofossils and associated
archaeological remains from a hyperarid drainage (Quebrada Maní, ∼21° S,
1000 m a.s.l.) in the Atacama Desert. During the late Holocene,
riparian ecosystems and farming social groups flourished in the hyperarid
Atacama core as surface water availability increased throughout this
presently sterile landscape. Twenty-six radiocarbon dates indicate that
these events occurred between 1050–680, 1615–1350 and 2500–2040 cal yr BP.
Regional comparisons with rodent middens and other records suggest that
these events were synchronous with pluvial stages detected at
higher-elevations in the central Andes over the last 2500 yr. These
hydroclimate changes also coincide with periods of pronounced SST gradients
in the Tropical Pacific (La Niña-like mode), conditions that are
conducive to significantly increased rainfall in the central Andean
highlands and flood events in the low-elevation watersheds at inter-annual
timescales. Our findings indicate that the positive anomalies in the
hyperarid Atacama over the past 2500 yr represent a regional response of
the central Andean climate system to changes in the global hydrological
cycle at centennial timescales. Furthermore, our results provide support for
the role of tropical Pacific sea surface temperature gradient changes as the
primary mechanism responsible for climate fluctuations in the central Andes.
Finally, our results constitute independent evidence for comprehending the
major trends in cultural evolution of prehistoric peoples that inhabited the
region. |
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