Following a very rainy period in the summer of 1950, oxygen temporarily reappeared in the hypolimnion of Lake Mendota. It is postulated that the oxygen was introduced there by density currents of cold, silt laden, well oxygenated runoff water.
Bryson, R. A., and V. E. Suomi. 1952. "Midsummer renewal of oxygen within the hypolimnion." Journal of Marine Research 10, (3). https://elischolar.library.yale.edu/journal_of_marine_research/753