Christopher J. Davies , Anne Pommier , Sam Greenwood , Alfred Wilson
{"title":"具有层状 Fe-Si(-S)内核的水星的热演化和磁演化","authors":"Christopher J. Davies , Anne Pommier , Sam Greenwood , Alfred Wilson","doi":"10.1016/j.epsl.2024.118812","DOIUrl":null,"url":null,"abstract":"<div><p>Elucidating the structure and composition of Mercury is important for understanding its interior dynamics and evolution. The planet is characterised by unusual chemical characteristics and a weak magnetic field generated in a large metallic core, and its early evolution was also marked by the presence of a magnetic field, widespread volcanism and global contraction. Here we develop a parameterised model of coupled core-mantle thermal and magnetic evolution considering a layered Fe-Si(-S) core structure with chemical and physical properties of the mantle and the core based on previous laboratory studies. We seek successful solutions that are consistent with observations of Mercury's long-lived dynamo, total global contraction, present-day crustal thickness, and present-day interior structure. Successful solutions have a mantle reference viscosity <span><math><mo>></mo><msup><mrow><mn>10</mn></mrow><mrow><mn>21</mn></mrow></msup></math></span> Pa s (corresponding to a present-day bulk mantle viscosity <span><math><mo>></mo><mn>2</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>20</mn></mrow></msup></math></span> Pa s), a silicon concentration in the core >13 wt%, a present inner core radius of <span><math><mo>∼</mo><mn>1000</mn><mo>−</mo><mn>1200</mn></math></span> km and a thermally stable layer ∼ <span><math><mn>500</mn><mo>−</mo><mn>800</mn></math></span> km thick below the core-mantle boundary. Our results show that if present, a molten FeS layer atop the core has minimal effect on Mercury's long-term thermal and magnetic evolution. Predictions from our models can be tested with upcoming Bepi-Colombo observations.</p></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0012821X24002450/pdfft?md5=fd9a671970d3ac4ec1d8c772fed14d12&pid=1-s2.0-S0012821X24002450-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Thermal and magnetic evolution of Mercury with a layered Fe-Si(-S) core\",\"authors\":\"Christopher J. Davies , Anne Pommier , Sam Greenwood , Alfred Wilson\",\"doi\":\"10.1016/j.epsl.2024.118812\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Elucidating the structure and composition of Mercury is important for understanding its interior dynamics and evolution. The planet is characterised by unusual chemical characteristics and a weak magnetic field generated in a large metallic core, and its early evolution was also marked by the presence of a magnetic field, widespread volcanism and global contraction. Here we develop a parameterised model of coupled core-mantle thermal and magnetic evolution considering a layered Fe-Si(-S) core structure with chemical and physical properties of the mantle and the core based on previous laboratory studies. We seek successful solutions that are consistent with observations of Mercury's long-lived dynamo, total global contraction, present-day crustal thickness, and present-day interior structure. Successful solutions have a mantle reference viscosity <span><math><mo>></mo><msup><mrow><mn>10</mn></mrow><mrow><mn>21</mn></mrow></msup></math></span> Pa s (corresponding to a present-day bulk mantle viscosity <span><math><mo>></mo><mn>2</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>20</mn></mrow></msup></math></span> Pa s), a silicon concentration in the core >13 wt%, a present inner core radius of <span><math><mo>∼</mo><mn>1000</mn><mo>−</mo><mn>1200</mn></math></span> km and a thermally stable layer ∼ <span><math><mn>500</mn><mo>−</mo><mn>800</mn></math></span> km thick below the core-mantle boundary. Our results show that if present, a molten FeS layer atop the core has minimal effect on Mercury's long-term thermal and magnetic evolution. Predictions from our models can be tested with upcoming Bepi-Colombo observations.</p></div>\",\"PeriodicalId\":11481,\"journal\":{\"name\":\"Earth and Planetary Science Letters\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-06-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0012821X24002450/pdfft?md5=fd9a671970d3ac4ec1d8c772fed14d12&pid=1-s2.0-S0012821X24002450-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Earth and Planetary Science Letters\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0012821X24002450\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earth and Planetary Science Letters","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0012821X24002450","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Thermal and magnetic evolution of Mercury with a layered Fe-Si(-S) core
Elucidating the structure and composition of Mercury is important for understanding its interior dynamics and evolution. The planet is characterised by unusual chemical characteristics and a weak magnetic field generated in a large metallic core, and its early evolution was also marked by the presence of a magnetic field, widespread volcanism and global contraction. Here we develop a parameterised model of coupled core-mantle thermal and magnetic evolution considering a layered Fe-Si(-S) core structure with chemical and physical properties of the mantle and the core based on previous laboratory studies. We seek successful solutions that are consistent with observations of Mercury's long-lived dynamo, total global contraction, present-day crustal thickness, and present-day interior structure. Successful solutions have a mantle reference viscosity Pa s (corresponding to a present-day bulk mantle viscosity Pa s), a silicon concentration in the core >13 wt%, a present inner core radius of km and a thermally stable layer ∼ km thick below the core-mantle boundary. Our results show that if present, a molten FeS layer atop the core has minimal effect on Mercury's long-term thermal and magnetic evolution. Predictions from our models can be tested with upcoming Bepi-Colombo observations.
期刊介绍:
Earth and Planetary Science Letters (EPSL) is a leading journal for researchers across the entire Earth and planetary sciences community. It publishes concise, exciting, high-impact articles ("Letters") of broad interest. Its focus is on physical and chemical processes, the evolution and general properties of the Earth and planets - from their deep interiors to their atmospheres. EPSL also includes a Frontiers section, featuring invited high-profile synthesis articles by leading experts on timely topics to bring cutting-edge research to the wider community.