This study presents 25 years of carefully processed gravity measurements from western France, offering a unique dataset to support investigations of long-term land motion and sea level change. The data are consistent with satellite-based observations and are made available for use in future geophysical and climate-related research.

Established in the southwest of France in 1875, the Socoa tide gauge is part of the national sea level monitoring network in France. Through a data archaeology exercise, a large part of the records of this gauge in paper format have been rescued and digitized. The digitized data were processed and quality controlled to produce a uniform hourly sea level time series covering 1875 to the present day. This new dataset is important for climate research on sea level rise, tides, and storm surges.

We produced a reanalysis of GNSS data near tide gauges worldwide within the International GNSS Service. It implements advances in data modelling and corrections, extending the record length by about 7 years. A 28 % reduction in station velocity uncertainties is achieved over the previous solution. These estimates of vertical land motion at the coast supplement data from satellite altimetry or tide gauges for an improved understanding of sea level changes and their impacts along coastal areas.

Relative sea level in Venice rose by about 2.5 mm/year in the past 150 years due to the combined effect of subsidence and mean sea-level rise. We estimate the likely range of mean sea-level rise in Venice by 2100 due to climate changes to be between about 10 and 110 cm, with an improbable yet possible high-end scenario of about 170 cm. Projections of subsidence are not available, but historical evidence demonstrates that they can increase the hazard posed by climatically induced sea-level rise.

We investigated the long-term changes of the principal tidal component M₂ along North Atlantic coasts, from 1846 to 2018. We analysed 18 tide gauges. We found that M₂ variations are consistent at all the stations in the North-East Atlantic, whereas some discrepancies appear in the North-West Atlantic. The similarity between the North Atlantic Oscillation and M₂ variations in the North-East Atlantic suggests a possible influence of the large-scale atmospheric circulation on the tide.