Recent Sea Level Trends
The rate of sea level change differs from one place to another and from one decade to the next.
Click the tabs above the map to see trends over the last 10 years, the last 20 years, and since the beginning of the satellite record in 1993. The maps show sea level trends from satellite altimetry (colored contours) and tide gauges (circles).
The satellite trends reflect changes in the sea surface height only, with most of the spatial variation resulting from the influence of winds blowing over the ocean. The tide gauge trends are relative to a fixed point on land and reflect changes in water level plus local vertical land motion. The land near a tide gauge can move up and down for a variety of reasons, such as earthquakes or ground-water withdrawal.
How well does the tide gauge network sample the ocean?
One way to evaluate the effectiveness of the global tide network is to test the ability of the network to produce an accurate estimate of global mean sea level (GMSL). Tide gauges sample the global ocean at a small number of discrete locations (< 300) that do not necessarily sample the ocean in an optimal way. The figure below shows the UHSLC’s Fast-Delivery Network Performance Metric, which we define as the spatial sampling error in estimates of GMSL from tide gauges in the Fast-Delivery Network. In general, the error decreases in time, which suggests an improving network that more effectively samples the global ocean. Read more here.