Altering runoff patterns of major waterways could impact ocean circulation H uman alteration of major waterways may cause more problems than drought downstream, according to a geologist who is studying circulation models of the ancient oceans. The Colorado River barely flows to the ocean and the Aral Sea is drying up. We do have the capacity to alter the amounts of freshwater that run off into the oceans and that could alter ocean circulation patterns. Bice, Eric J. Barron, professor of geosciences and director of Penn State's Earth System Science Center, and William H. Peterson, Earth System Science Center, are using a supercomputer-based model to look at the effects of continental runoff on ocean circulation patterns in the early Eocene, about 55 million years ago when the Earth was substantially warmer than it is now. The reason continental runoff can change ocean circulation patterns is that the fresh water running out of continental rivers decreases the salinity of the oceans' surface.
Natural evaporation tends to increase the salinity of the surface water.
Circulation in the oceans can be caused by colder water sinking below warmer water or saltier, denser water sinking below less salty water. If runoff stops, new salty areas could form to produce new deep water formation sites. This page was created by Annemarie Mountz .