Search results
Results from the WOW.Com Content Network
Over geologic time sea level has fluctuated by more than 300 metres, possibly more than 400 metres. The main reasons for sea level fluctuations in the last 15 million years are the Antarctic ice sheet and Antarctic post-glacial rebound during warm periods. The current sea level is about 130 metres higher than the historical minimum.
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 as gleaned from the stratigraphic record throughout the geological history. The first such curve is the Vail curve or Exxon curve. The names of the curve refer to the fact that in 1977 a team of ...
Earth's radius at sea level is 6,378.137 km (3,963.191 mi) at the equator. It is 6,356.752 km (3,949.903 mi) at the poles and 6,371.001 km (3,958.756 mi) on average. [ 4 ] This flattened spheroid, combined with local gravity anomalies, defines the geoid of the Earth, which approximates the local mean sea level for locations in the open ocean.
Older Peron warm and wet, global sea levels were 2.5 to 4 meters (8 to 13 feet) higher than the twentieth-century average 3900: 5.9 kiloyear event dry and cold. 3500: End of the African humid period, Neolithic Subpluvial in North Africa, expands Sahara Desert 3000 – 0: Neopluvial in North America 3,200–2,900: Piora Oscillation, cold ...
These data are compared to the reference (or datum) level usually called mean sea level. [3] While tides are usually the largest source of short-term sea-level fluctuations, sea levels are also subject to change from thermal expansion, wind, and barometric pressure changes, resulting in storm surges, especially in shallow seas and near coasts.
Sea level rise of 0.2-0.3 meters is likely by 2050. In these conditions what is currently a 100-year flood would occur every year in the New Zealand cities of Wellington and Christchurch. With 0.5 m sea level rise, a current 100-year flood in Australia would occur several times a year.
In the Messinian salinity crisis (also referred to as the Messinian event, and in its latest stage as the Lago Mare event) the Mediterranean Sea went into a cycle of partial or nearly complete desiccation (drying-up) throughout the latter part of the Messinian age of the Miocene epoch, from 5.96 to 5.33 Ma (million years ago).
Distinctive white lines trace the flow of surface currents around the world. An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. [ 1 ]