Holocene and Glacial Climate Change in the Desert Southwest, USA: New Isotopic Records from Speleothems

北美西南部沙漠的极端气候控制着水的可用性以及许多人类和自然系统的可持续性。仪器记录显示了过去一个世纪气候的显著变化，特别是与厄尔尼诺-南方涛动（ENSO）系统有关。来自树木年轮重建的更长的记录揭示了近几个世纪以来显著延长的（十年一次到几十年一次）干旱的复发。目前缺乏全新世和冰期尺度上西南沙漠气候的连续高分辨率记录。该奖项将资助一项研究计划，以开发该地区有前途的气候信息档案，即保存在洞穴沉积物中的记录。这项工作将产生第一个高度精确、年代准确、校准、复制的西南沙漠全新世和冰川气候记录。这项工作将包括扩大洞穴取样、现代洞穴监测校准、改进U/Th定年方法，以及开发和解释新的、可复制的全新世高分辨率气候记录。这项工作将对重建美国西南沙漠的气候记录作出重要贡献。外联部分包括当地洞穴探险者的参与、K-12教育和美国林务局的合作。

Climatic extremes in the desert southwest of North America control the availability of water and the sustainability of many human and natural systems. Instrumental records demonstrate significant variability of climate in the past century, particularly related to the El Nino-Southern Oscillation (ENSO) system. Longer records from tree-ring reconstructions reveal the recurrence of significant prolonged (decadal to multidecadal) droughts in recent centuries. Continuous high-resolution records of desert southwest climate on Holocene and glacial time scales are lacking. This award will fund a research program to develop a promising archive of climate information in this region, the records preserved in speleothems (cave deposits). This work will generate the first highly resolved, well-dated, calibrated, replicated records of Holocene and glacial climate in the desert southwest. This work will include expanded speleothem sampling, modern cave monitoring for calibration, improvement of U/Th dating methodologies, and the development and interpretation of new, replicated high-resolution climate records for the Holocene. This work should make important contributions to the reconstructed climatic records of the US desert southwest. Outreach components include the involvement of local cavers, K-12 education, and US Forest Service collaboration.