“Early Holocene sea level rise”的意思、由来-开放百科全书

The early Holocene sea level rise (EHSLR) was a significant jump in sea level

by about {{val|60|u=m}} during the early Holocene, between about 12,000 and 7,000 years ago, spanning the Eurasian Mesolithic.^[1] The rapid rise in sea level and associated climate change, notably the 8.2 ka cooling event,

and the loss of coastal land favoured by early farmers, may have contributed to the spread of the Neolithic to Europe.^[2]

During deglaciation since the Last Glacial Maximum, between about 20,000 to 7,000 years ago (20–7 ka), 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 ka, 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.^[3]^[4]

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.

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.^[6]

See also

References

1. ^D.E.Smith, S.Harrison, C.R.Firth, J.T.Jordan, "The early Holocene sea level rise", Quaternary Science Reviews, Volume 30, Issues 15–16, July 2011, Pages 1846-1860."The rise, of ca 60m, took place over most of the Earth as the volume of the oceans increased during deglaciation and is dated at 11,650–7000 cal. BP. The EHSLR was largely driven by meltwater release from decaying ice masses and the break up of coastal ice streams. [...] The impact of the EHSLR on climate is reviewed and it is maintained that the event was a factor in the 8200 BP cooling event, as well as in changes in ocean current patterns and their resultant effects. The EHSLR may also have enhanced volcanic activity, but no clear evidence of a causal link with submarine sliding on continental slopes and shelves can yet be demonstrated. The rise probably influenced rates and patterns of human migrations and cultural changes."
2. ^Chris S.M.Turney, Heidi Brown, "Catastrophic early Holocene sea level rise, human migration and the Neolithic transition in Europe", Quaternary Science Reviews, Volume 26, Issues 17–18, September 2007, Pages 2036-2041.
3. ^Cronin, T. M. (2012) Invited review: Rapid sea-level rise. Quaternary Science Reviews. 56:11-30.
4. ^¹Blanchon, P. (2011a) Meltwater Pulses. In: Hopley, D. (Ed), Encyclopedia of Modern Coral Reefs: Structure, form and process. Springer-Verlag Earth Science Series, p. 683-690. {{ISBN|978-90-481-2638-5}}
5. ^Blanchon, P. (2011b) Backstepping. In: Hopley, D. (Ed), Encyclopedia of Modern Coral Reefs: Structure, form and process. Springer-Verlag Earth Science Series, p. 77-84. {{ISBN|978-90-481-2638-5}}
6. ^¹Blanchon, P., and Shaw, J. (1995) Reef drowning during the last deglaciation: evidence for catastrophic sea-level rise and icesheet collapse. Geology, 23:4–8.