<P> 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 land -- 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 . </P>
<P> 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 land -- 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 . </P>
when did the sea level start to rise
when did the sea level start to rise
20,000 years ago
20,000 years ago