Water science news, explainers, and statistics covering freshwater, hydrology, lakes, rivers, groundwater, ice, and Earth’s connected water systems.
A bight is a long, broad, gentle bend or recess in a coastline that forms a large open bay. Compared with a compact cove, a bight spans more shoreline and remains widely exposed to the sea. The term can refer to the curve itself or to the coastal waters lying inside it. NOAA’s geographic definition…
More
Estuaries can be classified into five major circulation types: salt-wedge, fjord, slightly stratified, vertically mixed and freshwater. The categories describe how fresh water and seawater move or mix, not simply the shape of the coast. Density creates the starting pattern. Fresh river water is lighter and tends to flow seaward over denser saltwater entering below.…
Geologists classify estuaries into four major types according to how their basins formed: drowned river valleys, bar-built estuaries, tectonic estuaries and fjords. The shape inherited from sea-level rise, sediment movement, crustal motion or glaciers influences every later tide and current. The system describes origin rather than present-day water circulation. A fjord can behave like a…
Estuary salinity zones divide the transition from river water to seawater into named concentration ranges. In a common system, tidal fresh water is below 0.5 parts per thousand. Oligohaline water spans 0.5 to 5, mesohaline water 5 to 18, polyhaline water 18 to 30 and euhaline water approaches open-ocean salinity. The boundaries help scientists compare…
