Search results
Results From The WOW.Com Content Network
Relative sea level can change by the processes changing eustatic sea level (e.g., ice melt and thermal expansion), but also by changes on land such as subsidence and isostatic rebound. In sequence stratigraphy, relative sea level is similarly defined as the distance from the ocean surface to the bottom of the sediment on the ocean floor. [2]
Height above mean sea level (AMSL) is the elevation (on the ground) or altitude (in the air) of an object, relative to a reference datum for mean sea level (MSL). It is also used in aviation, where some heights are recorded and reported with respect to mean sea level (contrast with flight level ), and in the atmospheric sciences , and in land ...
Comparison of two sea level reconstructions during the last 500 Myr: Exxon curve and Hallam curve. The scale of change during the last glacial/interglacial transition is indicated with a black bar. The sea-level curve (also known as the eustatic curve) is the representation of the changes of the sea level relative to present day mean sea level ...
The most up-to-date chronology of sea level change through the Phanerozoic shows the following long-term trends: [16] Gradually rising sea level through the Cambrian; Relatively stable sea level in the Ordovician, with a large drop associated with the end-Ordovician glaciation; Relative stability at the lower level during the Silurian
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.
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.
Eustatic sea level is the sea level with reference to a fixed point, the centre of the Earth. Relative sea level is measured with reference to the base level, above which erosion can occur and below which deposition can occur. Both eustatic sea level changes and subsidence rates tend to be longer cycles.
Hypsometry (from Ancient Greek ὕψος (húpsos) 'height' and μέτρον (métron) 'measure') [1] [2] is the measurement of the elevation and depth of features of Earth's surface relative to mean sea level. [3] On Earth, the elevations can take on either positive or negative (below sea level) values.