Long-term vertical land motion from double-differenced tide gauge and satellite altimetry data
We present a new approach to estimate precise long-term vertical land motion (VLM) based on double-differences of long tide gauge (TG) and short altimetry data. We identify and difference rates of pairs of highly correlated sea level records providing relative VLM estimates that are less dependent on record length and benefit from reduced uncertainty and mitigated biases (e.g. altimeter drift). This approach also overcomes the key limitation of previous techniques in that it is not geographically limited to semi-enclosed seas and can thus be applied to estimate VLM at TGs along any coast, provided data of sufficient quality are available. Using this approach, we have estimated VLM at a global set of 86 TGs with a median precision of 0.7 mm/year in a conventional reference frame. These estimates were compared to previous VLM estimates at TGs in the Baltic Sea and to estimates from co-located Global Positioning System (GPS) stations and Glacial Isostatic Adjustment (GIA) predictions. Differences with respect to the GPS and VLM estimates from previous studies resulted in a scatter of around 0.6 mm/year. Differences with respect to GIA predictions had a larger scatter in excess of 1 mm/year. Until satellite altimetry records reach enough length to estimate precise VLM at each TG, this new approach constitutes a substantial advance in the geodetic monitoring of TGs with major applications in long-term sea level change and climate change studies.
KeywordsVertical land motion Tide gauges Satellite altimetry GPS
- Burgette RJ, Watson CS, Church JA, White NJ, Tregoning P, Coleman R (2013) Characterizing and minimizing the effects of noise in tide gauge time series: relative and geocentric sea level rise around Australia. Geophys J Int. doi:10.1093/gji/ggt131
- Johansson JM, Davis JL, Scherneck HG, Milne GA, Vermeer M, Mitrovica JX, Bennett RA, Jonsson B, Elgered G, Elósegui P, Koivula H, Poutanen M, Rönnäng BO, Shapiro II (2002) Continuous GPS measurements of postglacial adjustment in Fennoscandia 1. Geodetic results. J Geophys Res 107(B8):2157. doi:doi:10.1029/2001JB000400 Google Scholar
- Santamaría-Gómez A, Gravelle M, Collilieux X, Guichard M, Míguez BM, Tiphaneau P, Wöppelmann G (2012) Mitigating the effects of vertical land motion in tide gauge records using a state-of-the-art GPS velocity field. Global Planet Change 98–99:6–17. doi:10.1016/j.gloplacha.2012.07.0076 Google Scholar
- Teferle FN, Bingley RM, Orliac EJ, Williams SDP, Woodworth PL, McLaughlin D, Baker TF, Shennan I, Milne GA, Bradley SL, Hansen DN (2009) Crustal motions in Great Britain: evidence from continuous GPS, absolute gravity and Holocene sea level data. Geophys J Int 178(1):23–46. doi:10.1111/j.1365-246X.2009.04185.x23 CrossRefGoogle Scholar
- Wessel P, Smith WHF (1991) Free software helps map and display data. EOS Trans AGU 72, pp 441, 445–446Google Scholar