Kumgangsan, just north of the DMZJuly 27, 1931: A dry year at the beginning of America's "Dust Bowl" creates the Perfect Swarm, as grasshoppers overwhelm farmland in Iowa, Nebraska and South Dakota. Cornfields are eaten down to the stubs, and American agriculture suffers a disaster at the beginning of the Great Depression.

July 27, 1953: Score one for unintended, good, consequences: As part of their truce, North and South Korea establish a 155 mile-long, 2.5 mile-wide demilitarized zone between the two countries. Although there are heavy fortifications on both sides of the DMZ, there's very little in the middle. The Korean DMZ eventually gains fame as some of the most unspoiled temperate wildlife habitat in the world (at right).

July 27, 1986: The Discovery Channel gives birth to a ratings monster, as the first “Shark Week” begins broadcast. Featuring the gruesome-but-rare instances of shark attacks on humans, Discovery is later criticized for airing “shark porn,” and ignoring the millions of sharks taken by humans each year.

July 27, 2010: In the wake of the Deepwater Horizon oil spill, BP announces CEO Tony Hayward will leave the company on Oct. 1.

Photo: Wikimedia Commons

This feature is compiled by Peter Dykstra, an MNN contributor and publisher of Environmental Health News and The Daily Climate.

July 27
Grasshoppers overwhelm the American Midwest, and BP announces Tony Hayward's departure.