A widely repeated account holds that in 1984, scientists injected red dye under the ice of Lake Erken in Sweden and found that after 26 hours, about 95 percent of it remained in the uppermost seven meters. The "two teaspoons" figure often attached to this account does not match the dye quantities described in the underlying field research, so it should be treated as an unverified detail of the popular retelling rather than a number from the published study. That study is a genuine series of winter tracer tests carried out by hydrologist Lars Bengtsson, who released dye into three ice-covered Swedish lakes in 1984 and published the results two years later in Nordic Hydrology as Dispersion in Ice-Covered Lakes.
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