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DOI	10.1016/j.epsl.2019.116006
	Constraints on mantle viscosity and Laurentide ice sheet evolution from pluvial paleolake shorelines in the western United States
	Austermann J.; Chen C.Y.; Lau H.C.P.; Maloof A.C.; Latychev K.
发表日期	2020
ISSN	0012821X
卷号	532
英文摘要	The deformation pattern of the paleoshorelines of extinct Lake Bonneville were among the first features to indicate that Earth's interior responds viscoelastically to changes in surface loads (Gilbert, 1885). Here we revisit and extend this classic study of isostatic rebound with updated lake chronologies for Lake Bonneville and Lake Lahontan as well as revised elevation datasets of shoreline features. The first order domal pattern in the shoreline elevations can be explained by rebound associated with the removal of the lake load. We employ an iterative scheme to calculate the viscoelastic lake rebound, which accounts for the deformation of the solid Earth and gravity field, to calculate a lake load that is consistent with the load-deformed paleotopography. We find that the domal deformation requires a regional Earth structure that exhibits a thin elastic thickness of the lithosphere (15–25 km) and low sublithospheric Maxwell viscosity (∼1019 Pa s). After correcting for rebound due to the lake load, shoreline feature elevations reveal a statistically significant northward dipping trend. We attribute this trend to continent-scale deformation caused by the ice peripheral bulge of the Laurentide ice sheet, and take advantage of the position of these lakes on the distal flank of the peripheral bulge to provide new insights on mantle viscosity and Laurentide ice sheet reconstructions. We perform ice loading calculations to quantify the deformation of the solid Earth, gravity field, and rotation axis that is caused by the growth and demise of the Laurentide ice sheet. We test three different ice reconstructions paired with a suite of viscosity profiles and confirm that the revealed trend can be explained by deformation associated with the Laurentide ice sheet when low viscosities below the asthenosphere are adopted. We obtain best fits to shoreline data using ice models that do not have the majority of ice in the eastern sectors of the Laurentide ice sheet, with the caveat that this result can be affected by lateral variations in viscosity. We show that pluvial lakes in the western United States can place valuable constraints on the Laurentide ice sheet, the shape of its peripheral bulge, and the underlying mantle viscosity. © 2019 Elsevier B.V.
关键词	glacial isostatic adjustment Lake Bonneville Lake Lahontan Laurentide ice sheet mantle viscosity paleoshorelines
英文关键词	Deformation; Glaciers; Iterative methods; Lakes; Repair; Viscosity; Deformation pattern; Glacial Isostatic Adjustments; Isostatic rebound; Lateral variations; Laurentide ice sheets; Mantle viscosity; Paleoshorelines; Western United States; Ice; asthenosphere; coastal evolution; deformation; glacioisostasy; gravity field; Laurentide Ice Sheet; mantle source; paleoceanography; viscoelasticity; viscosity; Great Salt Lake; United States; Utah
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202474
作者单位	Lamont Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States; Massachusetts Institute of Technology, Woods Hole Oceanographic Institution Joint Program, Cambridge, MA 02139, United States; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, United States; Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, NJ 08544, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States
推荐引用方式 GB/T 7714	Austermann J.,Chen C.Y.,Lau H.C.P.,et al. Constraints on mantle viscosity and Laurentide ice sheet evolution from pluvial paleolake shorelines in the western United States[J],2020,532.
APA	Austermann J.,Chen C.Y.,Lau H.C.P.,Maloof A.C.,&Latychev K..(2020).Constraints on mantle viscosity and Laurentide ice sheet evolution from pluvial paleolake shorelines in the western United States.Earth and Planetary Science Letters,532.
MLA	Austermann J.,et al."Constraints on mantle viscosity and Laurentide ice sheet evolution from pluvial paleolake shorelines in the western United States".Earth and Planetary Science Letters 532(2020).