Sea-level change
Sea-level change is a rise or fall in the height of the sea surface relative to the land. It can be global or vary from place to place.
Thermal expansion: The increase in a substance’s volume as its temperature rises. Warming seawater expands, raising the global mean sea level without adding water.
Relative sea level: Sea-surface height measured relative to the adjacent land. This is the quantity that determines changing water levels at a particular coast.
Coastal flooding: The inundation of coastal land by seawater, often during storms, high tides, or unusually high water levels. A higher baseline lets tides and storm surges flood farther inland.
Storm surge: A temporary rise in coastal water level caused mainly by a storm’s winds and low atmospheric pressure. It is a short-lived event superimposed on the changing sea-level baseline.
Last Interglacial: The warm interval about 129,000 to 116,000 years ago, when global sea level stood above its modern level. Its highstand offers evidence about sea levels under a warmer climate.
Glacial isostatic adjustment: The ongoing deformation of Earth’s crust and mantle after the growth and melting of large ice sheets. Postglacial land uplift changes relative sea level even where ocean volume is stable.
Global mean sea level: The average height of the sea surface across the global ocean, relative to a reference surface. It isolates the broad ocean-wide trend from local land motion and regional variation.
Coastal erosion: The loss of coastal land through waves, currents, and other processes that remove sediment or rock. Rising water can shift wave action landward and increase shoreline retreat.
Tide: The periodic rise and fall of sea level caused mainly by the gravitational forces of the Moon and Sun. Tidal cycles recur regularly, unlike a persistent change in mean sea level.
Holocene sea-level rise: The rise in global sea level following the Last Glacial Maximum, continuing through much of the Holocene. This major postglacial rise shaped modern coastlines and human settlement patterns.