Knowledge Resource Center for Ecological Environment in Arid Area
| 项目编号 | 1850807 |
| The Southern Ocean's Iron Cycle through the Cenozoic | |
| Ann Dunlea (Principal Investigator) | |
| 主持机构 | Woods Hole Oceanographic Institution |
| 开始日期 | 2019 |
| 结束日期 | 2022 |
| 资助经费 | 415529(USD) |
| 项目类别 | Standard Grant |
| 资助机构 | US-NSF（美国国家科学基金会） |
| 语种 | 英语 |
| 国家 | 美国 |
| 英文简介 | Iron limits primary productivity in the modern Southern Ocean. This, in turn, reduces the amount of atmospheric carbon dioxide that is taken up by the high-latitude oceans. These observations raise a number of fascinating and hitherto unanswered questions, namely: what are the major sources of iron to the Southern Ocean? How resilient or variable is the supply of iron from these sources over geologic time? How has the iron cycle responded to long-term changes in Earth's climate? Have changes in the iron cycle influenced those of other nutrients, such as silica? This project will address these questions by means of a multifaceted approach examining the origin of the sediment, deposition rates, and quantification of iron sources therein. The detailed records obtained will be used to examine how changes in ocean nutrient cycles relate to the major tectonic, climatic, and biogeochemical reorganizations that have occurred over the past 66 million years ago. The holistic framework used will consider the interplay of these major Earth system processes and quantify their individual roles in shaping iron delivery to the largest iron-limited biome on Earth. This project will quantify the major sources of iron to the Southern Ocean and how they changed in space and time, based on the geochemistry of metal-rich deep-sea clay sequences drilled by the International Ocean Discovery Program. This will be achieved by combining statistical modeling of the origin of the clay with radiometrically-constrained deposition rates and explicit quantification of iron sources therein. The resultant reconstructions will be used to test hypotheses regarding: the significance of hydrothermally-derived iron to the high-latitude oceans over the Cenozoic; how the opening of tectonic gateways redistributed deeply-sourced iron within the Southern Ocean; how the supply of dust-derived iron changed as Australia became a desert; and, if there were changes in the iron cycle associated with the proliferation of diatoms. This project complements ongoing research conducted as part of the GEOTRACES program, will engage K-12 students from communities underrepresented in STEM, and will support two early-career researchers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. |
| 资源类型 | 项目 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/356185 |
| 推荐引用方式 GB/T 7714 | Ann Dunlea .The Southern Ocean's Iron Cycle through the Cenozoic.2019. |
| 条目包含的文件 | 条目无相关文件。 | |||||
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