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Crustal Displacements Due to Continental Water LoadingThe effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (delta-r(sub M)) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare delta-r(sub M) with observed Global Positioning System (GPS) heights (delta-r(sub O)) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the delta-r(sub O) time series are adjusted by delta-r(sub M), their variances are reduced, on average, by an amount equal to the variance of the delta-r(sub M). Of the delta-r(sub O) time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the delta-r(sub M). The delta-r(sub M) time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.
Document ID
20010114890
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
vanDam, T.
(National Museum of Natural History Walferdange, Luxembourg)
Wahr, J.
(Colorado Univ. Boulder, CO United States)
Milly, P. C. D.
(Geological Survey Princeton, NJ United States)
Shmakin, A. B.
(Geological Survey Princeton, NJ United States)
Blewitt, G.
(Nevada Bureau of Mines and Geology Reno, NV United States)
Lavallee, D.
(Newcastle-upon-Tyne Univ. Newcastle, United Kingdom)
Larson, K. M.
(Colorado Univ. Boulder, CO United States)
Date Acquired
August 20, 2013
Publication Date
February 15, 2001
Publication Information
Publication: Geophysical Research Letters
Publisher: American Geophysical Union
Volume: 28
Issue: 4
ISSN: 0094-8276
Subject Category
Geophysics
Report/Patent Number
Paper-2000GL012120
Funding Number(s)
CONTRACT_GRANT: NAG5-7703
CONTRACT_GRANT: NAG5-6147
Distribution Limits
Public
Copyright
Other

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