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Investigating the Origin of the Plume-Thermal Dichotomy on Venus
Investigating the Origin of the Plume-Thermal Dichotomy on Venus
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105159
- ISBN
- 9798270241667
- DDC
- 550
- 서명/저자
- Investigating the Origin of the Plume-Thermal Dichotomy on Venus
- 발행사항
- [Sl] : University of California, San Diego, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 224 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-06, Section: B.
- 주기사항
- Advisor: Stegman, David R.
- 학위논문주기
- Thesis (Ph.D.)--University of California, San Diego, 2025.
- 초록/해제
- 요약Venus's largest scale plume-driven features present themselves in a roughly bimodal distribution. Coronae, defined by their fractured annuli between ≈60 km to 1000 km (mean ≈240 km) in diameter, are generally smaller and more numerous (N 700) than large topographic rises (1000 km and N≈10) which are thought to be the surface expression of longer-lived plumes from the deep mantle. This dissertation explores the role that mineral phase transitions may play in the development of an internal boundary layer from which the small-scale (coronae-forming) plumes originate. Using 2D numerical simulations of compressible mantle convection of a pyrolite composition, stagnant lid planets such as Venus are shown to have a higher propensity towards mantle layering and mantle avalanches than mobile-lid planets, such as Earth, if they are similarly composed (Chapter 1). Additionally, this system of mantle layering and avalanches may provide a framework through which to explain the coexistence of coronae and large topographic rises on Venus: small-scale plumes develop from this internal boundary layer as well as via return flow from the mantle avalanches. Multiple scales as well as a diversity in the formation mechanisms and sizes of both mantle upwellings and downwellings are noted. Additionally, the dynamic topography signature in the numerical models is compared to the observed dynamic topography along a 7,000 km lava channel on Venus (Chapter 2). In Chapter 3, a closer look is taken at the effects of the same set of mineral phase transitions in pyrolite on the dynamics of heat flow through the surface of the planet. The study finds a nonintuitive trend in the Rayleigh-Nusselt scaling for hotter mantles where secondary convection occurs in the upper mantle. In Chapter 4, the challenge of quantitatively measuring plumes within numerical models of mantle convection is approached. The power-law trend in plume size and Rayleigh number is recovered as has been reported in experimental work with analog fluids. A Python toolkit is described that was developed for this purpose in Boussinesq convection models with future work aimed at applying the analysis to compressible convection models with mineral phase transitions.
- 일반주제명
- Geophysics
- 일반주제명
- Planetology
- 키워드
- Coronae
- 키워드
- Geodynamics
- 키워드
- Mantle plumes
- 키워드
- Venus
- 기타저자
- University of California, San Diego Scripps Institution of Oceanography
- 기본자료저록
- Dissertations Abstracts International. 87-06B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008260126s2025 us c eng d■001000017359694
■00520260202105159
■006m o d
■007cr#unu||||||||
■020 ▼a9798270241667
■035 ▼a(MiAaPQ)AAI32244414
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a550
■1001 ▼aKerr, Madeleine Carolyn.
■24510▼aInvestigating the Origin of the Plume-Thermal Dichotomy on Venus
■260 ▼a[Sl]▼bUniversity of California, San Diego▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a224 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-06, Section: B.
■500 ▼aAdvisor: Stegman, David R.
■5021 ▼aThesis (Ph.D.)--University of California, San Diego, 2025.
■520 ▼aVenus's largest scale plume-driven features present themselves in a roughly bimodal distribution. Coronae, defined by their fractured annuli between ≈60 km to 1000 km (mean ≈240 km) in diameter, are generally smaller and more numerous (N 700) than large topographic rises (1000 km and N≈10) which are thought to be the surface expression of longer-lived plumes from the deep mantle. This dissertation explores the role that mineral phase transitions may play in the development of an internal boundary layer from which the small-scale (coronae-forming) plumes originate. Using 2D numerical simulations of compressible mantle convection of a pyrolite composition, stagnant lid planets such as Venus are shown to have a higher propensity towards mantle layering and mantle avalanches than mobile-lid planets, such as Earth, if they are similarly composed (Chapter 1). Additionally, this system of mantle layering and avalanches may provide a framework through which to explain the coexistence of coronae and large topographic rises on Venus: small-scale plumes develop from this internal boundary layer as well as via return flow from the mantle avalanches. Multiple scales as well as a diversity in the formation mechanisms and sizes of both mantle upwellings and downwellings are noted. Additionally, the dynamic topography signature in the numerical models is compared to the observed dynamic topography along a 7,000 km lava channel on Venus (Chapter 2). In Chapter 3, a closer look is taken at the effects of the same set of mineral phase transitions in pyrolite on the dynamics of heat flow through the surface of the planet. The study finds a nonintuitive trend in the Rayleigh-Nusselt scaling for hotter mantles where secondary convection occurs in the upper mantle. In Chapter 4, the challenge of quantitatively measuring plumes within numerical models of mantle convection is approached. The power-law trend in plume size and Rayleigh number is recovered as has been reported in experimental work with analog fluids. A Python toolkit is described that was developed for this purpose in Boussinesq convection models with future work aimed at applying the analysis to compressible convection models with mineral phase transitions.
■590 ▼aSchool code: 0033.
■650 4▼aGeophysics
■650 4▼aPlanetology
■653 ▼aCoronae
■653 ▼aGeodynamics
■653 ▼aMantle convection
■653 ▼aMantle plumes
■653 ▼aMineral phase transitions
■653 ▼aVenus
■690 ▼a0373
■690 ▼a0590
■690 ▼a0467
■71020▼aUniversity of California, San Diego▼bScripps Institution of Oceanography.
■7730 ▼tDissertations Abstracts International▼g87-06B.
■790 ▼a0033
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359694▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
