气候变化领域集成服务门户(CCPortal): Geophysical constraints on the properties of a subglacial lake in northwest Greenland

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DOI	10.5194/tc-15-3279-2021
	Geophysical constraints on the properties of a subglacial lake in northwest Greenland
	Maguire R.; Schmerr N.; Pettit E.; Riverman K.; Gardner C.; Dellagiustina D.N.; Avenson B.; Wagner N.; Marusiak A.G.; Habib N.; Broadbeck J.I.; Bray V.J.; Bailey S.H.
发表日期	2021
ISSN	19940416
起始页码	3279
结束页码	3291
卷号	15 期号:7
英文摘要	In this study, we report the results of an active-source seismology and ground-penetrating radar survey performed in northwestern Greenland at a site where the presence of a subglacial lake beneath the accumulation area has previously been proposed. Both seismic and radar results show a flat reflector approximately 830-845ĝ€¯m below the surface, with a seismic reflection coefficient of -0.43ĝ€¯±ĝ€¯0.17, which is consistent with the acoustic impedance contrast between a layer of water and glacial ice. Additionally, in the seismic data we observe an intermittent lake bottom reflection arriving between 14-20ĝ€¯ms after the lake top reflection, corresponding to a lake depth of approximately 10-15ĝ€¯m. A strong coda following the lake top and lake bottom reflections is consistent with a package of lake bottom sediments although its thickness and material properties are uncertain. Finally, we use these results to conduct a first-order assessment of the lake origins using a one-dimensional thermal model and hydropotential modeling based on published surface and bed topography. Using these analyses, we narrow the lake origin hypotheses to either anomalously high geothermal flux or hypersalinity due to local ancient evaporite. Because the origins are still unclear, this site provides an intriguing opportunity for the first in situ sampling of a subglacial lake in Greenland, which could better constrain mechanisms of subglacial lake formation, evolution, and relative importance to glacial hydrology. © Author(s) 2021.
英文关键词	assessment method; geoaccumulation; geothermal power; ground penetrating radar; lacustrine deposit; salinity; sampling; seismic data; seismic reflection; subglacial environment; topography; Arctic; Greenland
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202369
作者单位	Department of Geology, University of Maryland, College Park, MD 20742, United States; Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, United States; College of Earth Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331-5503, United States; Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, United States; Department of Geosciences, Utah State University, Logan, UT 84322-4505, United States; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092, United States; Silicon Audio Inc., Pflugerville, TX 78660, United States; Department of Geosciences, University of Alaska, Fairbanks, AK 99775, United States
推荐引用方式 GB/T 7714	Maguire R.,Schmerr N.,Pettit E.,et al. Geophysical constraints on the properties of a subglacial lake in northwest Greenland[J],2021,15(7).
APA	Maguire R..,Schmerr N..,Pettit E..,Riverman K..,Gardner C..,...&Bailey S.H..(2021).Geophysical constraints on the properties of a subglacial lake in northwest Greenland.Cryosphere,15(7).
MLA	Maguire R.,et al."Geophysical constraints on the properties of a subglacial lake in northwest Greenland".Cryosphere 15.7(2021).