Crustal vertical motions inferred by tide gauges and satellite altimetry

In order to make use of the historic tide gauge records, Kuo et al. [2004] developed a useful algorithm to derive absolute vertical motions and demonstrated it in Fennoscandia. In this study, the slight improved algorithm is used to compute absolute vertical motions in the Great Lakes USA, the absolute vertical observation of each tide gauge station instead of averaged-lake vertical motion. The analysis includes examination of GIA models using different estimates of mantle thickness and upper and lower mantle viscosity and comparison with vertical motions relative to the outlet of Great Lakes [Mainville et al., 2003]. The comparison shows mean difference of 0.17 ± 0.72 mm/yr with ICE3G and -0.26 ± 0.50 mm/yr with respect to the study of Mainville et al. [2003]. The algorithm is extended to include absolute vertical motions for a linear model as well as quadratic model and has been tested in Alaska. The estimates show the quadratic model best describes the postseismic cycle after 1964 earthquake and rapid uplift rates in the area of the regional postglacial rebound. The solutions agree well with GPS solutions.