東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Modeling the Dynamics of Thwaites Gl...

Yu, Hongju.

FindBook

Google Book

Amazon

博客來

Modeling the Dynamics of Thwaites Glacier, West Antarctica.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Modeling the Dynamics of Thwaites Glacier, West Antarctica./
作者:	Yu, Hongju.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
面頁冊數:	126 p.
附註:	Source: Dissertations Abstracts International, Volume: 80-03, Section: B.
Contained By:	Dissertations Abstracts International80-03B.
標題:	Geophysics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10825001
ISBN:	9780438296459

Modeling the Dynamics of Thwaites Glacier, West Antarctica.
Yu, Hongju.

Modeling the Dynamics of Thwaites Glacier, West Antarctica. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 126 p.

Source: Dissertations Abstracts International, Volume: 80-03, Section: B.

Thesis (Ph.D.)--University of California, Irvine, 2018.

This item must not be sold to any third party vendors.

Thwaites Glacier (TG), West Antarctica, has been experiencing rapid mass loss and grounding line retreat in the past few decades. The mass loss of TG is now responsible for 4% of global sea level rise. It is therefore crucial to simulate the future evolution of TG to make projections for future sea level rise. The cause of the dramatic changes is dynamic through the loss of buttressing from its ice shelf due to calving and ice shelf melting. In this thesis, we employ various numerical ice sheet models to study the calving dynamics of TG and the response of TG to enhanced ice shelf melting. We combine a two-dimensional ice flow model with the linear elastic fracture mechanics (LEFM) theory to model crevasse propagation and ice fracturing. We find that the combination of a full-Stokes (FS) model and LEFM produces surface and bottom crevasses that are consistent with the distribution of depth and width of surface and bottom crevasses observed, whereas the combinations of simplified models with LEFM do not. We find that calving is enhanced when pre-existing surface crevasses are present, when the ice shelf is shortened, or when the ice shelf front is undercut. We show that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line of a glacier for constraining crevasse formation and iceberg calving. We then simulate the evolution of TG under different ice shelf melt scenarios and different ice sheet model configurations. We find that the grounding line retreat and its sensitivity to ocean forcing is enhanced when a full-Stokes model is used, ice shelf melt is applied on partially floating elements, and a Budd friction is used. Initial conditions also impact the model results. Yet, all simulations suggest a rapid, sustained retreat along the same preferred pathway. The highest retreat rate occurs on the eastern side of the glacier and the lowest rate on a subglacial ridge on the western side. Combining the results, we find the differences among simulations are small in the first 30 years, with a cumulative contribution to sea level rise of 5 mm, similar to the current rate. After 30 years, the mass loss highly depends on the model configurations, with a 300% difference over the next 100 years, ranging from 14 to 42 mm.

ISBN: 9780438296459Subjects--Topical Terms:

535228
Geophysics.

Modeling the Dynamics of Thwaites Glacier, West Antarctica.
LDR:03338nmm a2200313 4500 001 2210429
005 20191121124219.5
008 201008s2018 ||||||||||||||||| ||eng d
020 $a 9780438296459
035 $a (MiAaPQ)AAI10825001
035 $a (MiAaPQ)uci:15072
035 $a AAI10825001
040 $a MiAaPQ $c MiAaPQ
100 1 $a Yu, Hongju. $3 3283587
245 1 0 $a Modeling the Dynamics of Thwaites Glacier, West Antarctica.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 126 p.
500 $a Source: Dissertations Abstracts International, Volume: 80-03, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Rignot, Eric.
502 $a Thesis (Ph.D.)--University of California, Irvine, 2018.
506 $a This item must not be sold to any third party vendors.
520 $a Thwaites Glacier (TG), West Antarctica, has been experiencing rapid mass loss and grounding line retreat in the past few decades. The mass loss of TG is now responsible for 4% of global sea level rise. It is therefore crucial to simulate the future evolution of TG to make projections for future sea level rise. The cause of the dramatic changes is dynamic through the loss of buttressing from its ice shelf due to calving and ice shelf melting. In this thesis, we employ various numerical ice sheet models to study the calving dynamics of TG and the response of TG to enhanced ice shelf melting. We combine a two-dimensional ice flow model with the linear elastic fracture mechanics (LEFM) theory to model crevasse propagation and ice fracturing. We find that the combination of a full-Stokes (FS) model and LEFM produces surface and bottom crevasses that are consistent with the distribution of depth and width of surface and bottom crevasses observed, whereas the combinations of simplified models with LEFM do not. We find that calving is enhanced when pre-existing surface crevasses are present, when the ice shelf is shortened, or when the ice shelf front is undercut. We show that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line of a glacier for constraining crevasse formation and iceberg calving. We then simulate the evolution of TG under different ice shelf melt scenarios and different ice sheet model configurations. We find that the grounding line retreat and its sensitivity to ocean forcing is enhanced when a full-Stokes model is used, ice shelf melt is applied on partially floating elements, and a Budd friction is used. Initial conditions also impact the model results. Yet, all simulations suggest a rapid, sustained retreat along the same preferred pathway. The highest retreat rate occurs on the eastern side of the glacier and the lowest rate on a subglacial ridge on the western side. Combining the results, we find the differences among simulations are small in the first 30 years, with a cumulative contribution to sea level rise of 5 mm, similar to the current rate. After 30 years, the mass loss highly depends on the model configurations, with a 300% difference over the next 100 years, ranging from 14 to 42 mm.
590 $a School code: 0030.
650 4 $a Geophysics. $3 535228
690 $a 0373
710 2 $a University of California, Irvine. $b Earth System Science - Ph.D.. $3 2100202
773 0 $t Dissertations Abstracts International $g 80-03B.
790 $a 0030
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10825001