A White Nile megalake during the last interglacial period

T. T. Barrows, Martin A. J. Williams, Stephanie C. Mills, G. A. T. Duller, L. Keith Fifield, D. Haberlah, Stephen G. Tims, Frances M. Williams

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

25 Dyfyniadau(SciVal)

Crynodeb

The eastern Sahara Desert of Africa is one of the most climatically sensitive areas on Earth, varying from lake-studded savannah woodland to hyperarid desert over the course of a glacial-interglacial cycle. In currently semiarid Sudan there is widespread evidence that a very large freshwater lake once fi lled the White Nile River valley. Here we present the first quantitative estimate for the dimensions of the lake and a direct age for the emplacement of its shoreline. Using a profi le dating approach with the cosmogenic nuclide 10Be, we estimate an exposure age of 109 ± 8 ka for this megalake, indicating that it probably formed during the last interglacial period. This age is supported by optically stimulated luminescence dating of Blue Nile paleochannels associated with the lake. Using a high-resolution digital elevation model, we estimate that the lake was more than 45,000 km2 in area, making it comparable to the largest freshwater lakes on Earth today. We attribute the lake’s existence to seasonal fl ood pulses as a result of local damming of the White Nile by a more southern position of the Blue Nile and greatly increased precipitation associated with an
enhanced monsoon.
Iaith wreiddiolSaesneg
Tudalennau (o-i)163-166
Nifer y tudalennau4
CyfnodolynGeology
Cyfrol42
Rhif cyhoeddi2
Dyddiad ar-lein cynnar06 Ion 2014
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 01 Chwef 2014

Ôl bys

Gweld gwybodaeth am bynciau ymchwil 'A White Nile megalake during the last interglacial period'. Gyda’i gilydd, maen nhw’n ffurfio ôl bys unigryw.

Dyfynnu hyn