Decontaminating tide gauge records for the influence of glacial isostatic adjustment: The potential impact of 3-D Earth structure

Author
Keywords
Abstract
We investigate the potential impact of lateral variations in mantle viscosity and lithospheric thickness on predictions of present-day relative sea-level change due to glacial isostatic adjustment (GIA). We consider three viscoelastic Earth models. The first is a 1-D model with a lithospheric thickness of 120 km and upper and lower mantle viscosities of 5 \texttimes 10<SUP>20</SUP> Pa s and 5 \texttimes 10<SUP>21</SUP> Pa s, respectively. The second model includes global lithospheric thickness variations and lateral heterogeneities in upper mantle viscosity ranging over three orders of magnitude, while the third model includes lateral variations in lower mantle viscosity alone. We find that the impact of 3-D structure is significant. Indeed, the difference between the 3-D and 1-D model predictions at ~300 sites with tide gauge records longer than 40 years duration is greater than 0.2 mm/yr and 0.5 mm/yr for 50\% and 25\% of the sites, respectively. The maximum difference exceeds several mm/yr. We conclude that efforts to decontaminate tide gauge records for ongoing GIA, to determine the rate and origin of global sea-level rise, should incorporate 3-D mantle structure into the GIA modelling.
Year of Publication
2006
Journal
Geophysical Research Letters
Volume
33
Number of Pages
24318
Date Published
12/2006
URL
http://adsabs.harvard.edu/abs/2006GeoRL..3324318K
DOI
10.1029/2006GL028448