when did the sea level start to rise
Sea level rise Various factors affect the volume or mass of the ocean, leading to long-term changes in eustatic sea level. The two primary influences are temperature (because the density of water depends on temperature), and the mass of water locked up on land and sea as fresh water in rivers, lakes, glaciers and polar ice caps. Over much longer geological timescales, changes in the shape of oceanic basins and in landâ€“sea distribution affect sea level. Since the Last Glacial Maximum about 20,000 years ago, sea level has risen by more than 125 m, with rates varying from tenths of a mm/yr to 10+mm/year, as a result of melting of major ice sheets.[15]
Aral Sea By 1960, between 20 and 60 km3 (4.8 and 14.4 cu mi) of water each year was going to the land instead of the sea. Most of the sea's water supply had been diverted, and in the 1960s, the Aral Sea began to shrink. From 1961 to 1970, the Aral's level fell at an average of 20 cm (7.9 in) a year; in the 1970s, the average rate nearly tripled to 50–60 cm (20–24 in) per year, and by the 1980s, it continued to drop, now with a mean of 80–90 cm (31–35 in) each year. The rate of water use for irrigation continued to increase; the amount of water taken from the rivers doubled between 1960 and 2000, and cotton production nearly doubled in the same period.