Water science news, explainers, and statistics covering freshwater, hydrology, lakes, rivers, groundwater, ice, and Earth’s connected water systems.
A vast circulation system carries warm surface water north through the Atlantic and returns colder water south at depth. Known as the Atlantic Meridional Overturning Circulation, or AMOC, it redistributes heat across an entire ocean basin and influences climate far beyond the water itself. NOAA’s AMOC overview describes the circulation as part of a larger…
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Benjamin Franklin and Nantucket sea captain Timothy Folger produced the first widely recognized chart of the Gulf Stream in the late 1760s. Their map answered a practical postal puzzle: packets sailing west from Britain often took longer to reach New York than experienced American whalers expected. Folger knew where the fast current ran and Franklin…
Sea level does not form a smooth, uniform shell around Earth. The ocean surface follows the planet’s uneven gravity field, while currents, temperature and winds create additional slopes and bumps. A tide gauge also measures water against moving land, so two coasts can record different changes even while the global ocean gains the same total…
Most coastlines experience two high tides and two low tides during a lunar day, which lasts about 24 hours and 50 minutes. The usual interval from one high tide to the next is therefore close to 12 hours and 25 minutes. Local coastlines complicate that simple pattern, leaving some places with one daily high and…
