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Developing Water-Isotope Records From Stratigraphically Disturbed Blue Ice: Observations, Limitations, and Insights From the Allan Hills of Antarctica
Developing Water-Isotope Records From Stratigraphically Disturbed Blue Ice: Observations, Limitations, and Insights From the Allan Hills of Antarctica
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202103101
- ISBN
- 9798288820823
- DDC
- 551.6
- 서명/저자
- Developing Water-Isotope Records From Stratigraphically Disturbed Blue Ice: Observations, Limitations, and Insights From the Allan Hills of Antarctica
- 발행사항
- [Sl] : University of Washington, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 160 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-01, Section: B.
- 주기사항
- Advisor: Steig, Eric J.
- 학위논문주기
- Thesis (Ph.D.)--University of Washington, 2025.
- 초록/해제
- 요약Polar ice cores contain direct archives of past atmosphere and past precipitation, and water-isotope measurements of polar ice-core samples are used to reconstruct Earth's past climate. Ice cores from stable domes or ice divides - where post-depositional ice flow results primarily from compression of more recently accumulated snowfall - have produced continuous climate records as old as 800 ka. Climate records from older ice cores are of interest due to a notable change in Earth's climatic fluctuations around 1 Ma. Extending the ice-core paleoclimate record beyond 1 Ma likely requires measurements from more complicated depositional environments, such as from blue ice areas at the margins at the Antarctic ice sheet. The Allan Hills blue-ice area contains ice as old as 6 Ma at relatively shallow depths (200 m below the surface), but cores from this region are typically discontinuous and stratigraphically disturbed. In addition, they have likely experienced orders of magnitude more thinning than more typical ice cores, severely limiting their temporal resolution.The development and interpretation of ice-core climate records from blue-ice areas is still in nascent stages, and is only possible due to the development of an absolute dating technique by the analysis of atmospheric 40Ar (Bender et al., 2008). Age constraints at discrete depths along the core provide information about the average age of the ice, but significant uncertainty remains about the amount of time represented by each measurement. Here, I present new water-isotope records from discontinuous blue-ice cores from the Allan Hills blue ice area of Antarctica, and explore the implications and limitations of those data. This thesis uses high-resolution water-isotope data to explore the integrated history of ice recovered from the Allan Hills. This thesis (1) details advancements in high-resolution water-isotope measurement methodology by continuous-flow analysis, which is the preferred method for analyzing many Allan Hills cores, (2) advances our understanding of water-isotope signal preservation and alteration in blue ice by examining the reproducibility of the water-isotope record at lateral distances of 0.22 to 140 m, (3) demonstrates that climate signals are preserved in some disturbed Allan Hills ice and provides insights into ice accumulation and climate history in this area, and (4) explores differences in water-isotope distillation pathways caused by atmosphere and ocean changes between the present-day and a warmer (i.e. 6-Ma) world.
- 일반주제명
- Paleoclimate science
- 일반주제명
- Geochemistry
- 일반주제명
- Environmental science
- 키워드
- Blue ice
- 키워드
- Ice core science
- 키워드
- Paleoclimate
- 키워드
- Water isotopes
- 기타저자
- University of Washington Earth and Space Sciences
- 기본자료저록
- Dissertations Abstracts International. 87-01B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■020 ▼a9798288820823
■035 ▼a(MiAaPQ)AAI31934262
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a551.6
■1001 ▼aDavidge, Lindsey.
■24510▼aDeveloping Water-Isotope Records From Stratigraphically Disturbed Blue Ice: Observations, Limitations, and Insights From the Allan Hills of Antarctica
■260 ▼a[Sl]▼bUniversity of Washington▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a160 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-01, Section: B.
■500 ▼aAdvisor: Steig, Eric J.
■5021 ▼aThesis (Ph.D.)--University of Washington, 2025.
■520 ▼aPolar ice cores contain direct archives of past atmosphere and past precipitation, and water-isotope measurements of polar ice-core samples are used to reconstruct Earth's past climate. Ice cores from stable domes or ice divides - where post-depositional ice flow results primarily from compression of more recently accumulated snowfall - have produced continuous climate records as old as 800 ka. Climate records from older ice cores are of interest due to a notable change in Earth's climatic fluctuations around 1 Ma. Extending the ice-core paleoclimate record beyond 1 Ma likely requires measurements from more complicated depositional environments, such as from blue ice areas at the margins at the Antarctic ice sheet. The Allan Hills blue-ice area contains ice as old as 6 Ma at relatively shallow depths (200 m below the surface), but cores from this region are typically discontinuous and stratigraphically disturbed. In addition, they have likely experienced orders of magnitude more thinning than more typical ice cores, severely limiting their temporal resolution.The development and interpretation of ice-core climate records from blue-ice areas is still in nascent stages, and is only possible due to the development of an absolute dating technique by the analysis of atmospheric 40Ar (Bender et al., 2008). Age constraints at discrete depths along the core provide information about the average age of the ice, but significant uncertainty remains about the amount of time represented by each measurement. Here, I present new water-isotope records from discontinuous blue-ice cores from the Allan Hills blue ice area of Antarctica, and explore the implications and limitations of those data. This thesis uses high-resolution water-isotope data to explore the integrated history of ice recovered from the Allan Hills. This thesis (1) details advancements in high-resolution water-isotope measurement methodology by continuous-flow analysis, which is the preferred method for analyzing many Allan Hills cores, (2) advances our understanding of water-isotope signal preservation and alteration in blue ice by examining the reproducibility of the water-isotope record at lateral distances of 0.22 to 140 m, (3) demonstrates that climate signals are preserved in some disturbed Allan Hills ice and provides insights into ice accumulation and climate history in this area, and (4) explores differences in water-isotope distillation pathways caused by atmosphere and ocean changes between the present-day and a warmer (i.e. 6-Ma) world.
■590 ▼aSchool code: 0250.
■650 4▼aPaleoclimate science
■650 4▼aGeochemistry
■650 4▼aEnvironmental science
■653 ▼aBlue ice
■653 ▼aIce core science
■653 ▼aMid-Pleistocene transition
■653 ▼aPaleoclimate
■653 ▼aWater isotopes
■690 ▼a0653
■690 ▼a0996
■690 ▼a0768
■71020▼aUniversity of Washington▼bEarth and Space Sciences.
■7730 ▼tDissertations Abstracts International▼g87-01B.
■790 ▼a0250
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17356919▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
