[01] A. Parker, School of Engineering and Physical Science, James Cook University, Townsville, Australia.

The paper discusses a claim of variable subsidence rate of -2 to -4 mm per year for the Fremantle tide gauge (TG). It is shown as the GPS monitoring is still progressing, and far from delivering accurate subsidence rates of inland domes far from the TG location with relative motion unassessed. It is also shown as the TG signal of Fremantle shows natural oscillations of the relative sea levels up to a quasi-60 years’ multi-decadal periodicity about a constant trend SLR_,R of about +1.7 mm/year over more than one century. It is concluded that the most likely subsidence rate of the TG instrument VLM is -1.7 mm/year and constant.

GPS, Time Series, Fremantle

[01] www.psmsl.org/products/trends [02] Parker, A., M. Saad Saleem and M. Lawson (2013), Sea-Level Trend Analysis for Coastal Management, Ocean and Coastal Management. Ocean & Coastal Management, 73: 63–81. [03] N-A Mörner and A. Parker (2013), Present-to-future sea level changes: The Australian case, Environmental Sciences: An Indian Journal, 8(2): 43-51. [04] Parker, A. (2013), MINIMUM 60 YEARS OF RECORDING ARE NEEDED TO COMPUTE THE SEA LEVEL RATE OF RISE IN THE WESTERN SOUTH PACIFIC, Nonlinear Engineering. 3(1): 1–10. [05] Parker, A. (2014), Confirming the lack of any sea level acceleration around the Australian coastline, Nonlinear Engineering Nonlinear Engineering. 3(2): 99–105. [06] A. Parker (2014), Accuracy and Reliability Issues in the Use of Global Positioning System and Satellite Altimetry to Infer the Absolute Sea Level Rise, Journal of Satellite Oceanography and Meteorology, 1(1): 13-23. [07] www.sonel.org/spip.php?page=gps&idStation=812 [08] sideshow.jpl.nasa.gov/post/links/PERT.html [09] sealevel.colorado.edu/content/map-sea-level-trends [10] W. E. Featherstone, N. T. Penna, M. S. Filmer and D. P. Williams (2015), Nonlinear subsidence at Fremantle, a long-recording tide gauge in the Southern Hemisphere, Journal of Geophysical Research: Oceans, DOI: 10.1002/2015JC011295. [11] www.sonel.org/spip.php?page=gps&idStation=1918 [12] www.sonel.org/-Sea-level-trends-.html?lang=en [13] www.psmsl.org/data/obtaining/stations/111.php