Vertical land motion (VLM) of the Earth's crust occurs over diverse spatial and temporal scales, driven by surface mass-loading, anthropogenic influences, and tectonic processes (e.g., Pfeffer et al., 2017). VLM provides the key connection between relative sea-level (RSL) derived from a tide gauge (TG) and absolute sea-level (ASL) derived from a satellite altimeter (ALT, e.g., Church & White, 2011). ASL data is mainly comprised of ALT-inferred time series with a near-global coverage, while RSL is typically observed along well-developed coasts (Neumann et al., 2015). In the areas with sparse long-term TG records, improved understanding of VLM is critical to help plan better sea-level rise adaptation pathways at local and regional scales (Cazenave et al., 2014;Church et al., 2013;Woodworth et al., 2011).VLM at TG locations is obtained from geodetic observations or, in many cases, inferred from models of glacial isostatic adjustment (GIA). VLM is directly observable using space-borne techniques such as GNSS (of which global positioning system (GPS) is the most frequently used, for example, Hammond et al., 2016;Santamaría-Gómez et al., 2011), and TG VLMs are often interpolated from GPS velocities (e.g., Bouin & Wöppelmann, 2010). In the absence of nearby GPS, GIA rates are alternatively applied (e.g., Hay et al., 2015;Spada & Galassi, 2012), with an often-untested assumption that GIA is the dominant contributor to VLM.
