Collaborative Research: Upper Ocean Paleotemperatures: Direct Measurement Using ODP Geothermal Instrumentation

合作研究：上层海洋古温度：使用 ODP 地热仪器直接测量

• 批准号: 9416735
• 负责人: Andrew Fisher
• 金额: --
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-03-15 至 1997-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9416735&HistoricalAwards=false
• 关键词: Collaborative; Research; Upper; Ocean; Paleotemperatures

9416735 Fisher This project involves researchers from Woods Hole Oceanographic Institution and Indiana University. They will analyse temperature and thermal conductivity measurements of sediments at two sites drilled on the eastern U.S. continental slope by the Ocean Drilling Program (ODP). The will also carry out instrument calibrations which will allow future collection of such data at drilling sites of opportunity. The objective of the research is to examine ocean temperature change, particularly in "intermediate" water depths, which is important in understanding global climate change over the past few thousand years. The data in hand was collected at two ODP sites located only 4.4 kilometers apart near the edge of the Gulf Stream off New Jersey. The two temperature profiles show a dramatic difference in the upper sediment temperature gradient, and the investigators have modelled the data, suggesting that a plausible interpretation is that the position of the Gulf Stream has changed measurably over the past 100 to 130 years, affecting the shallower site but not the deeper one. Their observations are consistent with a 5-7 degree (Celsius) temperature change over that time period at the shallower site, in about 440 meters water depth. Such large temperature change is not commonly observed at these depths. The research carried out under this award will allow them to extend their modelling to examine both the hypothesis they propose (changes in Gulf Stream location) as well as other possible causes (subsurface aquifer flow, sediment slumping are examples) for the observed temperature and conductivity profiles. Data will be compared with historical measurements of water column temperature in the region, as well as with published "proxy" measurements of longer-term temperature which are obtained through analysis of isotopes of oxygen preserved in planktonic foraminifera skeletons. This award also provides funds to carry out a precise calibration of the instrumentation for measuring subs urface temperatures to remove uncertainties associated with instrument error in the future. ***

9416735费舍尔这个项目涉及来自伍兹霍尔海洋研究所和印第安纳州大学的研究人员。 他们将分析大洋钻探计划（ODP）在美国东部大陆斜坡钻探的两个地点的沉积物的温度和热导率测量结果。 他们还将进行仪器校准，以便将来在有机会的钻探地点收集这些数据。 这项研究的目的是研究海洋温度的变化，特别是在“中间”水深，这对了解过去几千年来的全球气候变化很重要。 手头的数据是在两个ODP站点收集的，这两个站点相距仅4.4公里，靠近新泽西的墨西哥湾流边缘。 这两个温度剖面显示，上层沉积物温度梯度存在巨大差异，调查人员对数据进行了建模，表明一种合理的解释是，墨西哥湾流的位置在过去100至130年中发生了可测量的变化，影响了较浅的地点，但没有影响较深的地点。 他们的观测结果与在大约440米水深的较浅地点的5-7摄氏度温度变化一致。 如此大的温度变化在这些深度并不常见。 在该奖项下进行的研究将使他们能够扩展他们的建模，以检查他们提出的假设（墨西哥湾流位置的变化）以及其他可能的原因（地下含水层流动，沉积物滑塌是例子）。 数据将与该地区水柱温度的历史测量值以及通过分析南极有孔虫骨骼中保存的氧同位素获得的已发表的长期温度“代用”测量值进行比较。 该奖项还提供资金，用于对测量地下温度的仪器进行精确校准，以消除未来与仪器误差相关的不确定性。 ***