Absolute fixing of tide gauge benchmarks

This project made it possible to separate estimates of sea level rises due to climate change. These rises were due to the subsiding land where the benchmarks were placed.

• From: Flood and Coastal Erosion Risk Management Research and Development Programme and Department for Environment, Food & Rural Affairs
• Published: 11 February 2021

• Category: Understanding risks from all sources of flooding
• Topics: Big data, Coast, Coastal erosion, Flood forecasting, Flood risk assessment, Hydrology, Non-stationarity, Sea level rise, Understanding physical processes
• Project status: Completed
• Project code: FD0305
• Date of completion: 31 March 2000

Documents

Absolute fixing of tide gauge benchmarks by GPS / Gravimetry - final report (2 KB) WORD

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Details

Trends in sea level rises are made up of two factors. These are:

• the change in sea levels related to climate change
• how far the land moves down due to subsidence

Tide gauges measure the sea level relative to a local Tide Gauge BenchMark (TGBM). This means that a rise can be due to climate change or subsidence in the land where the bench mark is placed.

Outcome

This project used new techniques, such as GPS and gravimetry, to measure the absolute position of the benchmarks and how their position changes. Separating the two factors improve the quality of the sea level data from around the UK coast. This provides real estimates of sea level rise rather than relative ones.

This project started in 1991 and was completed in 2000.

Published 11 February 2021