At the gauge Britain measures all height from, 36% of recorded sea-level rise is the pier sinking.

Every gauge, both instruments

Recorded = our OLS fit to PSMSL annual data since 1970. GNSS = vertical velocity of the ground at the monument (NGL MIDAS). InSAR = EGMS average across surrounding measured cells — town context, not the monument. Implied absolute = recorded + GNSS: the sea's own rise once the land is removed. Positive is up/rising; negative is down/sinking. All mm/yr.

Download: all 14 gauges, both instruments (CSV).

Method — so the result can be checked

1. Trends: ordinary least squares on PSMSL annual RLR values from 1970, requiring ≥ 30 years of data reaching past 2015. RLR is a datum for trends, never absolute levels.
2. Land motion, instrument one: nearest NGL MIDAS GNSS vertical velocity within 10 km (most are at the gauge itself), duration ≥ 5 years, uncertainty ≤ 1.5 mm/yr. MIDAS is a robust estimator that resists step errors (Blewitt et al. 2016).
3. Land motion, instrument two: EGMS InSAR (2020–2024) averaged over measured cells within 500 m of the gauge (2 km where the shoreline has no cells). This is the town's ground, not the monument's — kept as its own column.
4. No blending, no models: where the instruments disagree we print both; no glacial isostatic adjustment model is subtracted anywhere — the GPS measures the rebound directly.

Sea level: PSMSL (Permanent Service for Mean Sea Level) annual RLR series. Land motion: Nevada Geodetic Laboratory MIDAS velocities; ground motion © European Union, Copernicus Land Monitoring Service (EGMS). We did not produce the measurements; we produced the join. Analysis dated 2026-08-07. Related: Sinking Britain · The coastline England will not defend.

How can land motion change a sea-level record?

A tide gauge measures the sea relative to its own mounting. If the ground under the gauge sinks, the record shows extra rise that is really the land; if the ground rises, real sea-level rise is partly hidden. The convention is simple: recorded trend = the sea's own change minus the land's upward motion. That is why the same North Sea can produce different-looking records at Aberdeen (ground rising) and Lowestoft (ground sinking).

Why do your two land-motion instruments sometimes disagree?

Because they measure different things. The GNSS station is bolted to ground at the gauge and tracks that monument; the satellite InSAR figure averages measured cells across the surrounding town. At Sheerness the monument reads +1.4 mm/yr while the town average reads -0.8 — we print both and blend nothing, because the disagreement is information about the instruments, not an error to hide.

Is Britain really tilting?

At its own tide gauges, measurably yes. 4 gauges stand on ground still rising as Britain rebounds from the last ice age — Aberdeen, North Shields, Lerwick — while 5 stand on ground sinking, all in the south: Newlyn, Lowestoft, Holyhead, Portsmouth. The see-saw geophysicists model as glacial isostatic adjustment is visible in the GPS receivers mounted at the gauges themselves.

Why only fourteen gauges?

Honesty about records. PSMSL lists 75 British gauges, but a trend needs a long, current record — we required at least 30 years of annual data since 1970, running past 2015. 14 qualify. The others are shown in the download but carry no trend, because a short record's trend is noise wearing a suit.