A model of the 4000-year paleohydrology (δ 18 O) record from Lake Salpetén, Guatemala
A model of the 4000-year paleohydrology (δ 18 O) record from Lake Salpetén, Guatemala
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DOI：
10.1016/j.gloplacha.2015.07.006
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发表时间：
2016-03
影响因子：
3.9
通讯作者：
M. Rosenmeier;M. Brenner;D. Hodell;Jonathan B. Martin;J. Curtis;M. W. Binford
中科院分区：
文献类型：
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作者：
M. Rosenmeier;M. Brenner;D. Hodell;Jonathan B. Martin;J. Curtis;M. W. Binford
一个简单的质量平衡模型提供了深入了解流域植被变化和气候变化对水文和稳定氧同位素（δ 18 O）的演变萨尔佩滕湖，在危地马拉北方玛雅低地的影响。过去4000年的模型模拟纳入花粉推断的植被覆盖的变化，并占75%的变异观察到的生物碳酸盐δ 18 O记录从一个长的湖泊沉积物核心。然而，植被驱动的水文变化，未能捕捉到完整的晚全新世沉积物芯δ 18 O的变化。该模型需要纳入额外的变化，流域植被覆盖，包括区域降水量的变化，或可能两者兼而有之，以解释观察到的湖芯氧同位素记录的波动。对模型结果的气候解释表明，大约2400年至1800年前，有相对较大的水分可用性，但δ 18 O值的增加集中在~ 3300，2900，500和200日历年前（cal yr BP），表明降水量突然减少。有证据表明，长期干旱之间1500和800卡年BP。
A simple mass-balance model provides insights into the influence of catchment vegetation changes and climate variability on the hydrologic and stable oxygen isotope (δ18O) evolution of Lake Salpetén, in the Maya Lowlands of northern Guatemala. Model simulations for the last 4000 years incorporate pollen-inferred changes in vegetation cover and account for 75% of the variance observed in the biogenic carbonate δ18O record from a long lake sediment core. Vegetation-driven hydrologic changes, however, failed to capture the full range of late Holocene sediment core δ18O variability. The model requires incorporation of additional shifts in catchment vegetation cover, inclusion of regional precipitation changes, or likely both, to explain the fluctuations observed in the lake core oxygen isotope record. Climatic interpretation of the model results suggests that there was relatively greater moisture availability between about 2400 and 1800 years ago, but increased δ18O values centered at ~ 3300, 2900, 500, and 200 calendar years before present (cal yr BP) indicate abrupt precipitation decreases. There is evidence for protracted aridity between 1500 and 800 cal yr BP.