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The opposite of transgression is regression where the sea level falls relative to the land and exposes the former sea bottom. During the Pleistocene Ice Age, so much water was removed from the oceans and stored on land as year-round glaciers that the ocean regressed 120 m, exposing the Bering land bridge between Alaska and Asia.
As the balance shifts between the global cryosphere and hydrosphere, more of the planet's water in ice sheets means less in the oceans. At the height of the last ice age , around 18,000 years ago, the global sea level was 120 to 130 m (390-425 ft) lower than today.
The pressure effects of a tropical cyclone will cause the water level in the open ocean to rise in regions of low atmospheric pressure and fall in regions of high atmospheric pressure. The rising water level will counteract the low atmospheric pressure such that the total pressure at some plane beneath the water surface remains constant.
The typical tidal range in the open ocean is about 1 metre (3 feet) – mapped in blue and green at right. Mean ranges near coasts vary from near zero to 11.7 metres (38.4 feet), [ 4 ] with the range depending on the volume of water adjacent to the coast, and the geography of the basin the water sits in. Larger bodies of water have higher ...
The main factors affecting sea level are the amount and volume of available water and the shape and volume of the ocean basins. The primary influences on water volume are the temperature of the seawater, which affects density, and the amounts of water retained in other reservoirs like rivers, aquifers, lakes, glaciers, polar ice caps and sea ice.
The fall in sea level also affects the circulation of ocean currents and thus has important impact on climate during the glacial maximum. During deglaciation, the melted ice water returns to the oceans, thus sea level in the ocean increases again. However, geological records of sea level changes show that the redistribution of the melted ice ...
Water carried into the mantle eventually returns to the surface in eruptions at mid-ocean ridges and hotspots. [131]: 646 Estimates of the amount of water in the mantle range from 1 ⁄ 4 to 4 times the water in the ocean. [131]: 630–634 The deep carbon cycle is the movement of carbon through the Earth's mantle and core.
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range").