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Geodetic vertical velocities affected by recent rapid changes in polar motion
Citation
King, MA and Watson, CS, Geodetic vertical velocities affected by recent rapid changes in polar motion, Geophysical Journal International, 199, (2) pp. 1161-1165. ISSN 0956-540X (2014) [Refereed Article]
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Copyright Statement
Copyright 2014 The Authors
Abstract
Secular motion of Earth's rotation pole results in large-scale secular deformation of Earth. Here, we investigate the magnitude of the deformation that has resulted from the rapid motion of the rotation pole to the east since ~2005. We show that geodetic (GNSS, DORIS, VLBI and SLR) estimates of vertical velocity since ~2005 have been biased by up to ± 0.38 mm yr–1 relative to the longer-term deformation pattern. The largest signals occur within regions that include the U.S. Pacific Coast, Europe and South Pacific islands where geodetic measurements provide essential measurements of tide-gauge vertical movement and important constraints on models of glacial isostatic adjustment. Consequently, geodetic vertical velocities based on recent data should not be interpreted as being identical to centennial or longer term vertical land movement. Since 2010 the effect is further amplified by the overprediction of the IERS polar motion model relative to the ongoing secular change in pole position - during this time geodetic vertical velocities based on the IERS pole tide model are not just biased relative to the long-term rates but also from actual post-2010 Earth deformation. For geophysical or reference frame studies seeking geodetic vertical velocities that are representative of decadal timescales, where interannual variation is considered noise, the correction for this non-linear effect is straightforward, requiring an elastic computation using a reference rate of polar motion that is linear over the timescales of interest.
Item Details
Item Type: | Refereed Article |
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Keywords: | reference systems, sea level change, space geodetic surveys, Earth rotation variations, dynamics of lithosphere and mantle |
Research Division: | Earth Sciences |
Research Group: | Geophysics |
Research Field: | Geophysics not elsewhere classified |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the earth sciences |
UTAS Author: | King, MA (Professor Matt King) |
UTAS Author: | Watson, CS (Dr Christopher Watson) |
ID Code: | 100401 |
Year Published: | 2014 |
Web of Science® Times Cited: | 20 |
Deposited By: | Land and Food |
Deposited On: | 2015-05-14 |
Last Modified: | 2017-10-25 |
Downloads: | 347 View Download Statistics |
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