Coquina and tabby can look similar because both contain abundant shell fragments, yet one is a natural rock and the other is a manufactured building material. Coastal communities in Florida and the southeastern United States used each in structures that have survived centuries of salt air, storms and changing ownership. NOAA’s account of coquina and…
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The Atlantic Ocean covers about 106.5 million square kilometers, or 41.1 million square miles, when its connected seas are included. It occupies roughly one-fifth of Earth’s surface and separates the Americas from Europe and Africa. NOAA’s estimate of the Atlantic Ocean’s size makes it the world’s second-largest ocean basin after the Pacific. The figure can…
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…
A container ship approaching a bridge has to fit through a space that keeps changing. The vessel’s height above the water stays nearly fixed, yet tides, wind and river flow can raise or lower the surface beneath it. Even the bridge can move slightly as temperature and traffic loads change. Mariners call the vessel’s height…
