Tide
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Tides are the periodic rise and fall of sea level resulting from the differential gravitational forces exerted primarily by the Moon and the Sun, combined with inertial effects associated with the Ear
In Maine (U.S.), low tide occurs roughly at moonrise and high tide with a high Moon, corresponding to the simple gravity model of two tidal bulges; at most places however, the Moon and tides have a phase shift.
Low tide at Bangchuidao scenic area, Dalian, Liaoning Province, China
Low tide at Ocean Beach in San Francisco, California, U.S.
Low tide at Bar Harbor, Maine, U.S. (2014)
Sea level
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Mean sea level is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datum – a sta
This marker indicating sea level is situated between Jerusalem and the Dead Sea.
Sea level sign seen on cliff (circled in red) at Badwater Basin, Death Valley National Park
The Last Glacial Period caused a much lower global sea level.
Warming temperatures and melting glaciers are currently raising the sea level.