The canal structure imaged by the geophysical team was confirmed by analyzing sediment samples drilled from different depths.
The team traced the region's wet and dry periods over the past 30,000 years by analyzing sediment samples collected off the coast of Africa.
Now researchers from the Australian National University in Canberra, analyzing sediment cores from an area off the continent's northern coast that was partly exposed back then, have made what is considered the first such reliable measurement.
Researchers reconstructed the African dust plume over the last 23,000 years by analyzing sediment core samples from the Bahamas, pictured here.
The team traced the region's wet and dry periods over the past 30,000 years by analyzing sediment samples off the coast of Africa.
The scientists confirmed that their data from Baffin island was not just an anomaly by analyzing sediment cores from a glacial lake in Iceland.
For the study, financed by the Canadian government, the researchers set out to develop a historical record of the contamination, analyzing sediment dating back about 50 years from six small and shallow lakes north of Fort McMurray, Alberta, the center of the oil sands industry.
And they could analyze sediments from lakes with fish, painstakingly searching for mandibles of the phantom midge, to see if the lakes had once been fishless.
Avery Cook Shinneman, a biologist at the University of Washington, plans to analyze sediments at selected lakes in order to estimate abundances of livestock over time.
The researchers behind the current study, working on board the U.S. Coast Guard Cutter Healy, analyzed sediments of deep ocean mud, which contain the shells of long-dead marine organisms called foraminifera.
