Hurricane Impact on Seepage Water in Larga Cave, Puerto Rico
Hurricane Impact on Seepage Water in Larga Cave, Puerto Rico
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DOI：
10.1002/2017jg004218
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
R. Vieten;Sophie F. Warken;A. Winter;A. Schröder‐Ritzrau;D. Scholz;C. Spötl
中科院分区：
文献类型：
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作者：
R. Vieten;Sophie F. Warken;A. Winter;A. Schröder‐Ritzrau;D. Scholz;C. Spötl
波多黎各上空的飓风引起的降雨具有特征性的δ 18 O值，比当地降雨事件更负。因此，飓风可以记录在洞穴沉积物从拉尔加洞，波多黎各，作为特征氧同位素漂移。2012年至2013年期间，84个当地降雨样本的降雨量范围为-6.2至+0.3‰，而飓风艾萨克（2012年8月23日至24日）雨带的9个降雨样本的降雨量范围为-11.8至-7.1 ‰。洞穴监测涵盖了2014年飓风季节，并调查了飓风降雨对滴水化学的影响。对洞穴上方月降水样品进行了δ 18 O测定。在洞穴内，分析了瞬时滴水样品的δ 18 O值，并记录了6个滴水点的滴水速率。最有效的补给似乎发生在潮湿的月份（4月至5月和8月至11月）。瞬时滴水样品的δ 18 O值范围为−3.5 ‰至−2.4‰。2014年4月和2015年4月，一些滴水点的δ 18 O值比有效降雨量（-2.9 ‰）更负，这意味着飓风降雨在事件发生后数月至数年通过分层渗流到达洞穴。Larga洞穴滴水点的洞穴沉积物具有很高的古风暴学研究潜力。
Hurricane‐induced rainfall over Puerto Rico has characteristic δ18O values which are more negative than local rainfall events. Thus, hurricanes may be recorded in speleothems from Larga cave, Puerto Rico, as characteristic oxygen isotope excursions. Samples of 84 local rainfall events between 2012 and 2013 ranged from −6.2 to +0.3‰, whereas nine rainfall samples belonging to a rainband of hurricane Isaac (23–24 August 2012) ranged from −11.8 to −7.1‰. Cave monitoring covered the hurricane season of 2014 and investigated the impact of hurricane rainfall on drip water chemistry. δ18O values were measured in cumulative monthly rainwater samples above the cave. Inside the cave, δ18O values of instantaneous drip water samples were analyzed and drip rates were recorded at six drip sites. Most effective recharge appears to occur during the wet months (April–May and August–November). δ18O values of instantaneous drip water samples ranged from −3.5 to −2.4‰. In April 2014 and April 2015 some drip sites showed more negative δ18O values than the effective rainfall (−2.9‰), implying an influence of hurricane rainfall reaching the cave via stratified seepage flow months to years after the event. Speleothems from these drip sites in Larga cave have a high potential for paleotempestology studies.