| 项目编号: | 1725798
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| 项目名称: | EAR-PF: Mesozoic Geomagnetic Field Behavior: Exploring Mesozoic core dynamics by tuning numerical geodynamo simulations to paleomagnetic observations |
| 作者: | Margaret Avery
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| 承担单位: | Avery Margaret S
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| 批准年: | 2017
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| 开始日期: | 2017-11-01
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| 结束日期: | 2019-10-31
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| 资助金额: | 108649
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| 资助来源: | US-NSF
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| 项目类别: | Fellowship
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | magnetic field
; year
; field strength
; reversal rate
; core dynamics
; earth
; core-mantle
; observational constraint
; stem field
; numerical geodynamo simulation
; paleomagnetic observation
; research link
; geodynamo simulation
; core-mantle boundary condition
; core-mantle interaction
; time
; earth evolution
; numerical geodynamo numerical simulation
; nsf ear postdoctoral fellowship
; dr. avery
; outer-core flow
|
| 英文摘要: | Dr. Margaret S. Avery has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education activities at the University of California - Berkeley. The investigation focuses on building an updated compilation of paleomagnetic datasets for rocks from the Mesozoic area (251 - 65.5 million years ago) and running numerical geodynamo simulations. Using the geomagnetic field strength data measured from igneous rocks, Dr. Avery explores the relationship between polarity reversal rate and paleomagnetic field strength. This research links advanced geodynamo simulations with expanded paleomagnetic observations to enable better understanding of core dynamics and core-mantle boundary conditions during an important period of Earth evolution. For the education activities, Dr. Avery is developing and teaching a "Data Science Connector" course focused on geophysical data, specifically geomagnetism. In addition, she mentors an undergraduate student through the UC Berkeley's Society of Women in the Physical Sciences, and participates outreach activities, like the Expanding Your Horizons conference that introduces 5th-8th grade girls to careers in STEM fields.
The Earth's magnetic field varies on a broad range of timescales. It is to first order dipolar in structure, but the dipole varies is strength and polarity. The rate of polarity reversals varies on time-scales of tens of millions of years. For example, the magnetic field has reversed ~4 times per million years over the past 20 Myr, whereas no polarity reversals occurred for 38 Myr during the Cretaceous normal-polarity superchron. During the Jurassic, the reversal rate was much higher than the present rate (up to 14 reversals per million years). These drastic changes in reversal rate occur on such long periods that they likely are related to slow changes in the mantle that modulate the outer-core flow, providing information about Earth's thermal evolution. During times when the field strength was higher on average the reversal rate was low; in contrast, during times when the field strength was lower on average there was a high rate of reversals. Dr. Avery uses improved observational constraints and a new suite of numerical geodynamo numerical simulations. The geodynamo software Calypso is used to explore core dynamics and core-mantle interactions that could cause these differing geomagnetic field behaviors, and to test the hypothetical positive correlation between polarity reversal rate and paleointensity. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/88668
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Margaret Avery. EAR-PF: Mesozoic Geomagnetic Field Behavior: Exploring Mesozoic core dynamics by tuning numerical geodynamo simulations to paleomagnetic observations. 2017-01-01.
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