Distance from the center of the Earth to the sea surface
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The eustatic sea level is the distance from the center of the Earth to the sea surface.[1][2] An increase of the eustatic sea level can be generated by decreasing glaciation, increasing spreading rates of the mid-ocean ridges or increasing the number of mid-oceanic ridges. Conversely, increasing glaciation, decreasing spreading rates or fewer mid-ocean ridges can lead to a fall in the eustatic sea level.
Changes in the eustatic sea level lead to changes in accommodation and therefore affect the deposition of sediments in marine environments.
Eustatic (global) sea level refers to the volume of Earth's oceans.[3] This is not a physical level but instead represents the sea level if all of the water in the oceans were contained in a single basin.[4] Eustatic sea level is not relative to local surfaces, because relative sea level depends on many factors - including tectonics, continental rise and subsidence. Eustatic sea level follows the "bathtub approach" which describes the ocean as a single bathtub. One can add or remove water and Earth's oceans will gain or lose water globally. Differences in eustatic sea level over time stem from three main factors:
Changes in total ocean water mass, for instance, by ice-sheet runoff. When an ice sheet (such as Greenland) begins to lose some of its ice mass due to melt, the liquid water is transported to the ocean.[5] According to the "bathtub approach", ice-sheet runoff from Greenland will affect eustatic sea level in all areas of the world, whether nearby or distant. [3] Ocean water mass may shrink in size if the continental ice sheets grow in size, thereby removing liquid water from oceans and converting them to grow ice sheets [6]
Changes in the size of the ocean basin, for instance, by tectonic seafloor spreading or by sedimentation. These slow processes can cause the total volume of the oceanic basin to change.[7]
Density changes of the water, for instance, by thermal expansion. Warming will cause water to experience greater molecular motion, thus increasing the volume a molecule will occupy. Expansion of water may also be caused by changes in ocean salinity.[3] As continental ice accumulates, the ocean water freezes onto land but the salt it carried will mostly remain in the ocean. Thus, as ice sheets increase, ocean salinity also increases (and vice versa). An increase in salinity will increase the density of the ocean basin. Melting of ice sheets and a decrease of ocean salinity will effectively decrease the density of the water. These two effects together result in the steric sea level. The thermal part is called the thermosteric sea level, whereas the salinity part is called the halosteric sea level.[8]
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dictionary. The eustaticsealevel is the distance from the center of the Earth to the sea surface. An increase of the eustaticsealevel can be generated...
between sealevel and dry land. "relative" means change relative to a fixed point in the sediment pile. "eustatic" refers to global changes in sealevel relative...
Global or eustaticsealevel has fluctuated significantly over Earth's history. The main factors affecting sealevel are the amount and volume of available...
sealevel (RSL) is defined as the sealevel that is observed with respect to a land-based reference frame. It is often contrasted with eustaticsea level...
primarily in terms of changes in relative sealevel (the combination of global changes in eustaticsealevel and regional subsidence caused by tectonic...
ago), the eustaticsealevel was at 50-100 metres above the current sealevel, thus flooding the northern valleys connecting the Mediterranean Sea with the...
seas occur on a continent, not adjacent to it. The law of the sea does not apply to inland seas. In modern times, continents stand high, eustaticsea...
catastrophic sea-level rise and ice-sheet collapse. Geology. v. 23, no. 1, pp. 4–8. Fairbanks, R.G., 1989, A 17,000-year glacio-eustaticsea-level record:...
overcompensated by a eustaticsealevel rise. Thus, in areas of both eustatic and isostatic or tectonic influences, the course of the relative sealevel curve can...
rise and fall of the eustaticsealevel during geologic time. Sometimes it was connected with other shallow seas, such as the sea above the Paris Basin...
thickness, eustaticsealevel typically fell by over a 100 meters (330 ft). When these ice sheets shrank in extent and thickness, eustaticsealevel typically...
Caribbean Sea. The rates of sealevel rise associated with meltwater pulse 1A are the highest known rates of post-glacial, eustaticsealevel rise. Meltwater...
resulted from these changes. The exposure of the Sunda Shelf during eustaticsealevel changes has effects on the El Niño oscillation. W. Earle in 1845 was...
basins and modern ice caps. A drop of eustaticsealevel by about 60 to 120 metres (200 to 390 ft) from present-day levels, commencing around 30,000 years Before...
form either when sealevel rises or the land level fall. This can be caused by isostatic or eustatic change. Both isostatic and eustatic change can be caused...
the eustaticsealevel approached the current levels. The close correlation between population trends, regional temperatures, and eustaticsealevels suggest...
warm climate, resulting in high eustaticsealevels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine...
changes in eustaticsealevel. The growth of ice sheets led global sealevels to fall as water was lock away in glaciers. Falling sealevels exposed large...
global sea-level (i.e. eustatic) high-stand during the Holocene Epoch. Modern understanding of the various factors involved in quantifying eustaticsea level...
have long been reported in literature, but their significances in eustaticsea-level variation and chronostratigraphy have not been recognized until Vail...
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