https://scholars.lib.ntu.edu.tw/handle/123456789/493033
標題: | High-resolution speleothem record of precipitation from the Yucatan Peninsula spanning the Maya Preclassic Period | 作者: | Medina-Elizalde, M. Burns, S.J. Polanco-Mart?nez, J.M. Beach, T. Lases-Hern?ndez, F. CHUAN-CHOU SHEN Wang, H.-C. |
關鍵字: | Maya; Oxygen isotopes; Precipitation; Preclassic Period; Speleothem; Stalagmite | 公開日期: | 2016 | 卷: | 138 | 起(迄)頁: | 93-102 | 來源出版物: | Global and Planetary Change | 摘要: | We produced a new high-resolution absolute U-Th dated stalagmite oxygen isotope record (δ18O) from Río Secreto, Playa del Carmen, Yucatan Peninsula (YP). This new 1434-year stalagmite record (named Itzamna after the Maya god of creation) spans the time interval between BCE 1037 and CE 397 with an average resolution of 8 ± 2 years. It provides a novel view of climate evolution over the Preclassic and early Classic periods in Maya history. To understand the controls of regional precipitation δ18O on seasonal time scales, we characterized the amount effect between precipitation amount (P) and precipitation δ18O (δP). We found that precipitation δ18O in the Yucatan Peninsula is controlled by the amount effect on seasonal scales (δP/δP = -0.0137 ± 0.0031‰ per mm, r = 0.9), as suspected but never before demonstrated. Cave drip δ18O is consistent with the annual amount-weighted δ18O composition of precipitation. Multiple lines of evidence suggest that stalagmite δ18O reflects isotopic equilibrium conditions and thus stalagmite δ18O changes are interpreted to reflect precipitation amount. We determined quantitative precipitation changes from the stalagmite δ18O record following previous methods (Medina-Elizalde and Rohling, 2012). The stalagmite precipitation record suggests twelve periods of anomalous precipitation reductions ranging between about 30 and 70% below mean conditions at the time and with durations from 6 years to 31 years. Between BCE 520 and 166, the speleothem precipitation record suggests that the YP experienced an interval of high precipitation labeled the Late Preclassic Humid Period (LPHP) with precipitation maxima of up to +86 ± 20%. Preclassic Maya cultural expansion in El Mirador Basin, located in northern Guatemala, took place while the peninsula transitioned from the LPHP to an interval with below average precipitation. We find that the Preclassic abandonment of major centers in the Mirador Basin and others around the Maya Lowlands was synchronous with two unprecedented multi-decadal events of severe precipitation reduction with magnitudes of -55 ± 13% and -49 ± 12 and centered at CE 186 and 234, respectively. We also find evidence that centennial scale precipitation variability in the YP during the Preclassic Period may have been associated with shifts in rainfall fluxes from Atlantic tropical cyclones. © 2015 Elsevier B.V. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/493033 | DOI: | 10.1016/j.gloplacha.2015.10.003 | SDG/關鍵字: | Isotopes; Precipitation (chemical); Storms; Maya; Oxygen isotopes; Preclassic Period; Speleothem; Stalagmite; Precipitation (meteorology); climate variation; extreme event; oxygen isotope; paleoclimate; precipitation assessment; speleothem; stalagmite; uranium series dating; Maya Lowlands; Mirador Basin; Yucatan Peninsula |
顯示於: | 地質科學系 |
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