Glacial isostatic adjustment in 3-D earth models: Implications for the analysis of tide gauge records along the US east coast

被引:12
作者
Davis, Jonathan E. [1 ]
Latychev, Konstantin [1 ]
Mitrovica, Jerry X. [1 ]
Kendall, Roblyn [1 ]
Tamisiea, Mark E. [2 ]
机构
[1] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada
[2] Proudman Oceanog Lab, Liverpool L3 5DA, Merseyside, England
基金
英国自然环境研究理事会; 加拿大自然科学与工程研究理事会;
关键词
Tide gauges; US east coast; 3-D earth models; Glacial isostatic adjustment; Sea level change;
D O I
10.1016/j.jog.2008.04.007
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Tide gauge records of recent sea-level change along the U.S. east coast have received significant attention within the literature of glacial isostatic adjustment (GIA). Geographic trends in these tide gauge rates are not reduced by a GIA correction based on a commonly adopted radial viscosity profile (characterized, in particular, by a lower mantle viscosity similar to 1 - 2 x 10(21) Pa s), and this has led to speculation that the residual trends reflect contributions from neotectonics or oceanographic processes. While the trends can be significantly reduced by adopting an Earth model with a stiffer lower mantle, such a model appears to be incompatible with independent constraints from post-glacial decay times in Hudson Bay. We use a finite-element model of the GIA process to investigate whether 3-D viscosity variations Superimposed onto the "common" radial viscosity profile may provide a route to reconciling the east coast sea-level trends. We find that the specific 3-D structure we impose has little impact on the geographic trends in the GIA-corrected rates. However, we do find that the imposed lateral variations in lower mantle viscosity introduce a nearly uniform upward shift of 0.5 mm/yr in GIA-induced sea-level rates along the U.S. east coast. Thus, inferences of regional (U.S. east coast) sea-level rise due to modern melting of ice reservoirs, based on tide gauge rates corrected using 1-D GIA models, may be significantly biased by this simplifying assumption. (C) 2008 Elsevier Ltd. All rights reserved.
引用
收藏
页码:90 / 94
页数:5
相关论文
共 32 条
[1]  
CLARK JA, 1987, P INT C ROL POL REG, P356
[2]   Spatial variations in the rate of sea level rise caused by the present-day melting of glaciers and ice sheets [J].
Conrad, CP ;
Hager, BH .
GEOPHYSICAL RESEARCH LETTERS, 1997, 24 (12) :1503-1506
[3]   Glacial isostatic adjustment and the anomalous tide gauge record of eastern North America [J].
Davis, JL ;
Mitrovica, JX .
NATURE, 1996, 379 (6563) :331-333
[4]   GLOBAL SEA-LEVEL RISE [J].
DOUGLAS, BC .
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 1991, 96 (C4) :6981-6992
[5]   PRELIMINARY REFERENCE EARTH MODEL [J].
DZIEWONSKI, AM ;
ANDERSON, DL .
PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1981, 25 (04) :297-356
[6]   New inferences of mantle viscosity from joint inversion of long-wavelength mantle convection and post-glacial rebound data [J].
Forte, AM ;
Mitrovica, JX .
GEOPHYSICAL RESEARCH LETTERS, 1996, 23 (10) :1147-1150
[7]   GLOBAL SEA-LEVEL TREND IN THE PAST CENTURY [J].
GORNITZ, V ;
LEBEDEFF, S ;
HANSEN, J .
SCIENCE, 1982, 215 (4540) :1611-1614
[8]   Mantle dynamics, postglacial rebound and the radial viscosity profile [J].
Kaufmann, G ;
Lambeck, K .
PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 2000, 121 (3-4) :301-324
[9]   Decontaminating tide gauge records for the influence of glacial isostatic adjustment: The potential impact of 3-D Earth structure [J].
Kendall, Roblyn A. ;
Latychev, Konstantin ;
Mitrovica, Jerry X. ;
Davis, Jonathan E. ;
Tamisiea, Mark E. .
GEOPHYSICAL RESEARCH LETTERS, 2006, 33 (24)
[10]   Sea-level change, glacial rebound and mantle viscosity for northern Europe [J].
Lambeck, K ;
Smither, C ;
Johnston, P .
GEOPHYSICAL JOURNAL INTERNATIONAL, 1998, 134 (01) :102-144