Using continuous GPS and absolute gravity to separate vertical land movements and changes in sea-level at tide-gauges in the UK.
Researchers investigating climate change have used historical tide-gauge measurements from all over the world to investigate the changes in sea-level that have occurred over the last century or so. However, such estimates are a combination of any true sea-level variations and any vertical movements of the land at the specific tide-gauge. For a tide- gauge record to be used to determine the climate related component of changes in sea-level, it is therefore necessary to correct for the vertical land movement component of the observed change in sea-level.In 1990, the Institute of Engineering Surveying and Space Geodesy and Proudman Oceanographic Laboratory started developing techniques based on the Global Positioning System (GPS) for measuring vertical land movements (VLM) at tide-gauges in the UK. This paper provides brief details of these early developments and shows how they led to the establishment of continuous GPS (CGPS) stations at a number of tide-gauges. The paper then goes on to discuss the use of absolute gravity (AG), as an independent technique for measuring VLM at tide-gauges. The most recent results, from CGPS time-series dating back to 1997 and AG time-series dating back to 1995/1996, are then used to demonstrate the complementarity of these two techniques and their potential for providing site-specific estimates of VLM at tide-gauges in the UK.
Institute of Engineering Surveying and Space Geodesy (IESSG), University of Nottingham, Nottingham NG7 2RD, UK.
F N
FN
Teferle
R M
RM
Bingley
S D P
SD
Williams
T F
TF
Baker
A H
AH
Dodson
D002980:Climate; D005060:Europe; D040362:Geographic Information Systems; D005843:Geography; D006112:Gravitation; D011050:Policy Making; D017215:Satellite Communications; D012623:Seawater; D013997:Time Factors; D006113:United Kingdom; D014872:Water Movements