Relative Sea Level Trend
150-001 Delfzijl, Netherlands
The relative sea level trend is 1.8 millimeters/year with a 95% confidence
interval of +/-
0.13 mm/yr based on monthly mean sea level data from
1865 to 2021 which is equivalent to a change of 0.59 feet in 100 years.
Source Data & Additional Metadata
GLOSS Station Information
The plot shows the monthly mean sea level without the regular seasonal fluctuations due to coastal ocean temperatures,salinities, winds, atmospheric pressures, and ocean currents. The long-term linear trend is also shown, including its 95% confidence interval. Relative Sea Level trends at the coast can be positive or negative. A negative trend does not mean the ocean surface is falling; It indicates the land is rising more quickly than the ocean in a particular area. Trends close to zero indicate the land is rising at nearly the same rate as the ocean.
The plotted values are relative to the Revised Local Reference (RLR) datum as established by the Permanent Service for Mean Sea Level (PSMSL). The calculated trends for all stations are available as a table in millimeters/year and in feet/century (0.3 meters = 1 foot).If present, solid vertical lines indicate times of any major earthquakes in the vicinity of the station and dashed vertical lines bracket any periods of questionable data or datum shift.
Interannual Variation
150-001 Delfzijl, Netherlands
The plot shows the interannual variation of monthly mean sea level and the 5-month running average. The average seasonal cycle and linear sea level trend have been removed. Interannual variation is caused by irregular fluctuations in coastal ocean temperatures, salinities, winds, atmospheric pressures, and ocean currents. The interannual variation for many Pacific stations is closely related to the El Niño Southern Oscillation (ENSO). If present, solid vertical lines indicate times of any major earthquakes in the vicinity of the station and dashed vertical lines bracket any periods of questionable data or datum shifts.
Interannual Variation Since 1990
150-001 Delfzijl, Netherlands
The plot shows the interannual variation of monthly mean sea level and the 5-month running average. The average seasonal cycle and linear sea level trend have been removed. Interannual variation is caused by irregular fluctuations in coastal ocean temperatures, salinities, winds, atmospheric pressures, and ocean currents. The interannual variation for many Pacific stations is closely related to the El Niño Southern Oscillation (ENSO). If present, solid vertical lines indicate times of any major earthquakes in the vicinity of the station and dashed vertical lines bracket any periods of questionable data or datum shifts.
Average Seasonal Cycle
150-001 Delfzijl, Netherlands
The average seasonal cycle of mean sea level, caused by regular fluctuations in coastal temperatures, salinities, winds, atmospheric pressures, and ocean currents, is shown along with each month's 95% confidence interval. For local and regional comparisons, the calculated average seasonal values for all non CO-OPS and CO-OPS Stations are available as tables in meters.
Variation of 50-Year Relative Sea Level Trends
150-001 Delfzijl, Netherlands
Linear relative sea level trends were calculated in overlapping 50-year increments for stations with sufficient historical data. The variation of each 50-year trend, with 95% confidence interval, is plotted against the mid-year of each 50-year period. The solid horizontal line represents the linear relative sea level trend using the entire period of record.