Interactive map: Changes in Sea Level Over Time
By Rebecca Lindsey, Julia Engdahl, Nathan Murry, Analise Keeney, Ashley Miller, Chris Veras, and Audra Luscher.
Global sea level has risen between 6 and 8 inches (15-20 cm) over the last 100 years. About one third of the increase is due to the thermal expansion of ocean water as it has gotten warmer, and about two-thirds is due to meltwater flowing back to the ocean as glaciers and ice sheets on land melt.
Global sea level rise is about what’s happening to the ocean as a whole. At a local scale, the change can be more or less than the global average due to currents, natural climate variability, and things happening on land—like seismic activity, erosion, and subsidence. In some places, for example, coastal land is sinking due to groundwater pumping that causes the ground to slump.
The map–provided by NOAA–shows local sea level change as a linear long-term trend* at more than 100 of U.S. tide-monitoring stations in NOAA’s Center for Operational Oceanographic Products and Service (CO-OPS) network. Blue, upward arrows show where local sea level is rising. Brown, downward arrows show where local sea level is falling. Darker colors mean bigger changes.