Mean Sea Level Trends

The sea level trend map gives an indication of the differing rates of vertical land motion, given that the absolute global sea level rise is believed to be between 1.0 and 2.4 millimeters/year. The stations colored green are relatively stable with minimal vertical land movement. If a station's trend is greater than about 3 mm/yr, the land must be sinking and if the trend is less than 0 mm/yr, the land must be rising. A broad region of the mid-Atlantic coastline is sinking slowly due to the glacial rebound effect of the uplift of the Hudson Bay region since the end of the last ice age. The Mississippi delta region of Louisiana is rapidly sinking due to the loading of the lithosphere and compaction of the sediments deposited by the Mississippi river. The Texas coastline is also sinking, likely due to similar causes, in addition to oil and gas extraction. The volcanically active island of Hawaii is sinking relative to the other islands in the Hawaiian chain. Some areas of the northern California, Oregon, and Washington coastline are rising slowly due to the tectonic effects of subduction beneath the North American continent. Rapid uplift in southeastern Alaska is believed to be due to the melting of mountain glaciers. The trends for stations in southern Alaska and on the Aleutian islands were calculated based only on data since major earthquakes in March 1964 and March 1957, respectively. The trends show rapid post-earthquake tectonic uplift at most locations.

Comparison of northern Atlantic station trends	Comparison of northern Pacific station trends	Comparison of tropical station trends