Cretaceous palaeoclimate and palaeoceanography in the Pacific Ocean

太平洋白垩纪古气候和古海洋学

• 批准号: NE/H014071/1
• 负责人: Stuart Robinson
• 金额: $ 1.24万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH014071%2F1
• 关键词: Cretaceous; palaeoclimate; palaeoceanography; Pacific; Ocean

For much of Earth history atmospheric CO2 levels and average global temperatures are thought to have been much higher than present. These periods of time are known as 'greenhouse' climates. The Cretaceous (145 to 65 million years ago) was an extreme end-member of a greenhouse climate. Then the climate was much warmer than it is today; there was little or no polar ice and sea-levels were high. In polar areas, like Alaska and Antarctica, which are cold today, dinosaurs, crocodiles and tropical plants flourished. However, what the actual temperature of the ocean was during the Cretaceous is still much debated. Modern techniques allow us to use the chemical remains of bacteria found in ancient sediments to estimate what sea-surface temperatures were like in the past. To date, much of the work using this technique has focused on the Atlantic Ocean. However, during the Cretaceous the Pacific Ocean was the largest marine environment and thus estimates of temperature from there are most likely to represent 'global' conditions. Furthermore our knowledge of the environmental history of the Pacific Ocean during the Cretaceous is poor due to the small number of localities that have been sampled by deep-sea drilling. This project will determine Cretaceous sea-surface temperatures and environmental conditions by using samples from new sediment cores that will be drilled during Expedition 324 of the Integrated Ocean Drilling Program to Shatsky Rise in the northwest Pacific. By quantifying sea-surafce temperatures and oceanic environments in the Pacific Ocean during the Early Cretaceous we will be able to determine how warm the greenhouse climate was; whether temperatures varied between different ocean basins; and establish how oceanographic conditions varied through time.

在地球历史的大部分时间里，大气中的二氧化碳水平和平均全球温度被认为比现在高得多。这些时期被称为“温室”气候。白垩纪（145至6500万年前）是温室气候的极端成员。然后气候比今天温暖得多。几乎没有或没有极地冰，海平面很高。如今，如今寒冷的阿拉斯加和南极，如阿拉斯加和南极，恐龙，鳄鱼和热带植物蓬勃发展。但是，在白垩纪期间，海洋的实际温度仍在争论。现代技术使我们能够使用古代沉积物中发现的细菌的化学遗迹来估计过去的海面温度。迄今为止，使用这种技术的许多工作都集中在大西洋。但是，在白垩纪，太平洋是最大的海洋环境，因此，从那里开始的温度估计最有可能代表“全球”条件。此外，由于白垩纪期间太平洋环境历史的了解很差，因为深海钻探已经采样了少数地区。该项目将通过使用新的沉积物核心的样品来确定白垩纪的海面温度和环境条件，这些样品将在综合海洋钻探计划的探险324期间进行钻探，以达到西北太平洋的Shatsky上升。在白垩纪早期的太平洋中量化了太平洋的海上气温和海洋环境，我们将能够确定温室气候的温暖程度。不同的海盆之间的温度是否有所不同；并确定海洋条件如何随时间变化。

项目成果

An emerging palaeoceanographic 'missing link': multidisciplinary study of rarely recovered parts of deep-sea Santonian-Campanian transition from Shatsky Rise

新兴的古海洋学“缺失环节”：对沙茨基海隆深海桑托尼亚-坎帕尼亚过渡部分罕见恢复的部分进行多学科研究

• DOI: 10.1144/jgs2012-137
• 发表时间: 2013
• 期刊: Journal of the Geological Society
• 影响因子: 2.7
• 作者: Ando A