Map of low oxygen levels during a July 20-21, 2011, cruise east of the Mississippi River, with hypoxia, levels between zero and 2 parts per million in bottom water, in red, outlined by the black line.

These parts of the country, especially those east of the Mississippi River, are also where the frequency of tornadoes is increasing, according to Victor Gensini, an associate professor of ...

Drought’s deadly fingers have moved east, from the dried-up wells of California’s Central Valley and into the American Midwest, where much of America’s food is grown, and even farther, into ...

Map of low oxygen levels during a July 20-21, 2011, cruise east of the Mississippi River, with hypoxia, levels between zero and 2 parts per million in bottom water, in red, outlined by the black line.