NE Pacific sedimentary geomagnetic network analysis (GNA) to facilitate a better understanding of time, climate, and the geomagnetic field

GSTDTAP

项目编号	1929486
	NE Pacific sedimentary geomagnetic network analysis (GNA) to facilitate a better understanding of time, climate, and the geomagnetic field
	Joseph Stoner (Principal Investigator)
主持机构	Oregon State University
项目开始年	2019
	2019-08-01
项目结束日期	2021-07-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	498378(USD)
国家	美国
语种	英语
英文摘要	Chronology and dating of paleo-records is a fundamental challenge that confronts our understanding of global systems. Radiocarbon is a remarkable tool for meeting this challenge by allowing determination of precise ages in diverse environments that are less than around 50,000 years old. However, beyond the Holocene (last 11,500 years), due to limitations of the method, it is often impossible to make meaningful comparisons between records where uncertainties of a thousand years or less are required. Century to millennial variations in the direction and intensity of the Earth's geomagnetic field, known as paleomagnetic secular variation (PSV), offer an alternate signal that can be used for detailed stratigraphic alignment. This project will further the development of geomagnetic network analysis (GNA), a new approach based on the combining of multiple PSV records to improve our use of radiocarbon to tell time in the past. Utilizing a series of Integrated Ocean Drilling Program (IODP) drill cores from the NE Pacific, the research team will produce critical data that will improve understanding of Earth's magnetic field and yield high-resolution age models that will benefit the larger earth science community. The resulting chronology will improve our understanding of NE Pacific millennial scale climate, while also serving as a foundation for global paleomagnetic comparisons needed to test our understanding of secular variation and magnetic field changes. The project supports two early career investigators, one from an underrepresented group, and provides student training at the graduate and undergraduate levels. In addition, a short course will be developed and implemented to train other potential users. Improved radiocarbon to calendar age corrections and new data modeling approaches constrain and reduce uncertainties of both dates and the age models that run between them, making radiocarbon an almost 'one-stop shop' for high precision, highly accurate, and well constrained chronologies. Yet, beyond the Holocene, due to a host of both practical and intrinsic limitations on the number, the precision, and accuracy of those dates, it is often impossible to make meaningful comparisons between records where millennial or shorter uncertainties are required, making it difficult to test many Earth system hypotheses. The paleomagnetic record of geomagnetic change offers several approaches that may avoid some of these pitfalls. Centennial to millennial variations in direction and intensity of the geomagnetic field, known as paleomagnetic secular variation (PSV), offer an environmentally independent signal that can be used for detailed stratigraphic alignment. Based on the reasonable assumption that sediments within a limited geographic region have experienced a common geomagnetic history, one can use the PSV record to align stratigraphies irrespective of age. These depth-to-depth correlations, referred to as a geomagnetic network analysis (GNA), allow regional organization of chronological constraints from multiple sequences to be combined into a single age-depth profile. As a result, chronological precision and even accuracy can be improved, while reconstructing the paleomagnetic record of a region through time. GNA could greatly benefit our chronological understanding at many locations around the globe but needs to be tested and evaluated. This project will develop, assess, and quantify many of the aspects of GNA starting with a series of IODP cores from the NE Pacific that are optimal because of their very high sedimentation rates. The research team will obtain additional radiocarbon dates, XRF scanning, CT scanning, and paleomagnetic data (u-channel and discrete) to facilitate a chronostratigraphic modeling study that will combine the records using PSV and their independent radiocarbon chronologies into a single merged depth scale to facilitate a much more detailed understanding of the depth to age transformation. As a result, this project potentially sets the stage for the next generation of magnetic stratigraphy. The project will support two early career researchers and includes student training at the graduate and undergraduate levels. 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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/214173
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Joseph Stoner .NE Pacific sedimentary geomagnetic network analysis (GNA) to facilitate a better understanding of time, climate, and the geomagnetic field.2019.