Zee Media Bureau\Philaso G Kaping
New Delhi: A large freshwater lake once filled the White Nile valley in Sudan, according to a new study.
Researchers from the University of Exeter found that the lake was formed during the last interglacial period. They dated the shoreline sediments to about 109,000 years ago using a dating technique based on exposure to cosmic rays to measure the amount of the isotope beryllium-10 in n shoreline deposits, according to reports.
“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 filled the White Nile River valley,” the researchers said in a statement.
They also estimated that the ancient lake once measured more 45,000 km2 in area, similar to the largest freshwater lakes on Earth today.
The lake could have formed as a result of damming of the White Nile by a more southern position of the Blue Nile, accompanied by heavy rainfall during monsoon.
The findings have been published in the journal Geology.