气候变化领域集成服务门户(CCPortal): Tidal Pressurization of the Ocean Cavity Near an Antarctic Ice Shelf Grounding Line

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DOI	10.1029/2019JC015562
	Tidal Pressurization of the Ocean Cavity Near an Antarctic Ice Shelf Grounding Line
	Begeman C.B.; Tulaczyk S.; Padman L.; King M.; Siegfried M.R.; Hodson T.O.; Fricker H.A.
发表日期	2020
ISSN	21699275
卷号	125 期号:4
英文摘要	Mass loss from the Antarctic ice sheet is sensitive to conditions in ice shelf grounding zones, the transition between grounded and floating ice. To observe tidal dynamics in the grounding zone, we moored an ocean pressure sensor to Ross Ice Shelf, recording data for 54 days. In this region the ice shelf is brought out of hydrostatic equilibrium by the flexural rigidity of ice, yet we found that tidal pressure variations at a constant geopotential surface were similar within and outside of the grounding zone. This implies that the grounding zone ocean cavity was overpressurized at high tide and underpressurized at low tide by up to 10 kPa with respect to glaciostatic pressure at the ice shelf base. Phase lags between ocean pressure and vertical ice shelf motion were tens of minutes for diurnal and semidiurnal tides, an effect that has not been incorporated into ocean models of tidal currents below ice shelves. These tidal pressure variations may affect the production and export of meltwater in the subglacial environment and may increase basal crevasse heights in the grounding zone by several meters, according to linear elastic fracture mechanics. We find anomalously high tidal energy loss at the K1 constituent in the grounding zone and hypothesize that this could be explained by seawater injection into the subglacial environment at high tide or internal tide generation through interactions with topography. These observations lay the foundation for improved representation of the grounding zone and its tidal dynamics in ocean circulation models of sub–ice shelf cavities. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	ice fracture; Ross Ice Shelf; Ross Sea; subglacial hydrology; tide; Whillans Ice Stream
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186928
作者单位	Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, United States; Fluid Dynamics and Solid Mechanics, Los Alamos National Laboratory, Los Alamos, NM, United States; Earth and Space Research, Corvallis, OR, United States; School of Geography and Spatial Sciences, School of Technology, Environments and Design, University of Tasmania, Hobart, TAS, Australia; Institute of Geophysics and Planetary Physics, Scripps Institute of Oceanography, University of California, La Jolla, CA, United States; Department of Geophysics, Colorado School of Mines, Golden, CO, United States; Department of Geology and Environmental Geosciences, Northern Illinois University, DeKalb, IL, United States
推荐引用方式 GB/T 7714	Begeman C.B.,Tulaczyk S.,Padman L.,et al. Tidal Pressurization of the Ocean Cavity Near an Antarctic Ice Shelf Grounding Line[J],2020,125(4).
APA	Begeman C.B..,Tulaczyk S..,Padman L..,King M..,Siegfried M.R..,...&Fricker H.A..(2020).Tidal Pressurization of the Ocean Cavity Near an Antarctic Ice Shelf Grounding Line.Journal of Geophysical Research: Oceans,125(4).
MLA	Begeman C.B.,et al."Tidal Pressurization of the Ocean Cavity Near an Antarctic Ice Shelf Grounding Line".Journal of Geophysical Research: Oceans 125.4(2020).