Early Holocene sea level rise  The early Holocene sea level rise (EHSLR) was a significant jump in sea level by about during the early Holocene, between about 12,000 and 7,000 years ago, spanning the Eurasian Mesolithic. The rapid rise in sea level and associated climate change, notably the 8.2 ka cooling event (8,200 years ago), and the loss of coastal land favoured by early farmers, may have contributed to the spread of the Neolithic to Europe. During deglaciation since the Last Glacial Maximum, between about 20,000 to 7,000 years ago (20–7 ka), the sea level rose  by a total of about 100 m, at times at extremely high rates, due to the rapid melting of the British-Irish Sea, Fennoscandian, Laurentide, Barents-Kara, Patagonian, Innuitian and parts of the Antarctic ice sheets. At the onset of deglaciation about 19,000 years ago, a brief, at most 500-year long, glacio-eustatic event may have contributed as much as 10 m to sea level with an average rate of about 20 mm/yr. During the rest of the early Holocene, the rate of sea level rise varied from a low of about 6.0–9.9  mm/yr to as high as 30–60  mm/yr during brief periods of accelerated sea level rise. Solid geological evidence, based largely upon analysis of deep cores of coral reefs, exists only for three major periods of accelerated sea level rise, called "meltwater pulses", during the last deglaciation. The first, Meltwater pulse 1A, lasted between c. 14.6–14.3 ka, a 13.5 m rise over about 290 years centered at 14.2 ka. The EHSLR spans Meltwater pulses 1B and 1C, between 12,000 and 7,000 years ago: Such rapid rates of sea level rising during meltwater events clearly implicate major ice-loss events related to ice sheet collapse. The primary source may have been meltwater from the Antarctic ice sheet. Other studies suggest a Northern Hemisphere source for the meltwater in the Laurentide Ice Sheet.