The ultra-warm Arctic ca. 90 million years ago

超温暖的北极大约。

• 批准号: 1107801
• 负责人: John Tarduno
• 金额: $ 92.53万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1107801&HistoricalAwards=false
• 关键词: ultra; warm; Arctic; ca.; 90

The geologic history of the Arctic region records past climatic conditions that can provide insight into modern conditions and the potential for future change. The focus of this proposed work is on an excursion within the Cretaceous greenhouse world to ultra-warm conditions, approximately 90 million years ago. Evidence for both high temperature and anomalous CO2 volcanic outgassing is found in the geology of the High Arctic. The former comes in the form of a spectacular assemblage of vertebrate fossils found on Axel Heiberg Island, including large-bodied crocodile-like champsosaurs, turtles and fish. The latter is inferred by the presence of continental flood basalts and the Alpha-Mendeleev Oceanic Ridge; these features may form one of Earth's most voluminous large igneous provinces. The investigators propose multidisciplinary studies in the High Arctic to improve understanding of the absolute age and paleotemperatures associated with the vertebrate fossils (carbon and oxygen isotope analyses) and the absolute age and duration of the anomalous volcanism (radiometric age and paleomagnetic analyses). With these data, the investigators will test prior interpretations calling for high mean annual temperatures without seasonal ice, and whether contemporaneous pulses of volcanic activity could have contributed to the inferred warming by altering atmospheric CO2. The work proposed will contribute to at least one Ph.D. thesis and will involve undergraduates who will receive field training in the High Arctic and in the laboratory. The investigators also propose outreach efforts including collaboration with local K-12 schools and the use of new media to disseminate results of their study to the general public.

北极地区的地质历史记录了过去的气候状况，可以洞悉现代条件以及未来变化的潜力。这项拟议的工作的重点是大约9000万年前，在白垩纪温室世界中的一次旅行。高温和异常的二氧化碳火山量超过散热的证据都在高北极的地质学中发现。前者以在Axel Heiberg岛上发现的脊椎动物化石组合形式出现，其中包括大型鳄鱼，乌龟和鱼类。大陆洪水盆地和Alpha-Mendeleev Oceanic Ridge的存在是推断后者的；这些特征可能构成了地球最庞大的大火成岩省之一。研究人员提出了高北极的多学科研究，以提高对与脊椎动物化石（碳和氧同位素分析）以及异常火山主义（辐射年龄和古征分析）相关的绝对年龄和古植物的了解。通过这些数据，研究人员将测试先前的解释，要求没有季节性冰的高平均年度温度，以及火山活动的同期脉冲是否可以通过改变大气CO2来导致推断变暖。拟议的工作将至少贡献一位博士学位。论文并将涉及将在北极和实验室接受现场培训的大学生。调查人员还提出了推广工作，包括与当地K-12学校的合作以及使用新媒体将其研究结果传播给公众。