Mega Disasters

It has been a century since the infamous 1906 San Francisco earthquake and Californians live with the knowledge that it's only a matter of time before they're hit again. Los Angeles is the second most populous city in America. If an earthquake hit directly beneath downtown LA, scientists believe that tens of thousands would be killed. Just how would the city respond to a 7.5 magnitude quake? Take a look at how well the emergency responders could cope. A CGI worst-case scenario will show the incredible damage and destruction that would cripple one of the most important cities in the world.

The locust is one of the most destructive and dreaded life forms on Earth. American pioneers faced the largest swarm of locusts ever recorded. The 1,800 mile long and 110-mile-wide cloud of insects ate their way through the heartland and blocked the sun for five days. Famine ensued, and thousands faced starvation. According to recent studies, the possibility of such a swarm returning to the United States is very likely. The destruction would be unimaginable. This scenario is now generally believed by entomologists to be impossible. The Rocky Mountain locust, the insect responsible for the aforementioned swarm, has not been sighted since 1902. Efforts to breed modern North American grasshoppers to recreate the locust have all failed, and recent mitochondrial DNA analysis has strongly suggested that the Rocky Mountain locust was a distinct species.

An earthquake in New York City may seem like the plot of a bad movie, but a magnitude 5 quake occurred in 1884 and could happen again. Two faults run under Manhattan Island, including the 125th Street Fault where the landscape dips and the subway crosses on an open bridge. Since skyscrapers are designed to withstand windspeeds of 100 mph, most would survive sans windows; however, mid-sized masonry structures would collapse. As well, buildings (including smaller skyscrapers) built on landfill in Battery Park are subject to soil liquefaction, tipping over entirely in a major earthquake.

Methane gas precipitates out of the Earth's crust but is easily diluted in the air and in the oceans. Yet, according to one scientist, certain oceanic conditions could trap the gas in regions with low water circulation and build up extreme pressure. Once these areas are disturbed, the gas would blow out of the ocean in powerful jets. If they ignited before diluting, the explosion could cause widespread devastation. The scientist also posits that a similar event caused the Permian extinction.

As temperatures rise, a global meltdown has begun. From the Andes to the Himalayas to the Alps, glaciers are vanishing. In Antarctica and Greenland, vast ice sheets are turning into liquid. The melting ice, running off land, is raising sea levels. As sea levels rise, oceans throughout the world are also becoming hotter. Warmer seas fuel more intense hurricanes. Already, major catastrophes brought on by the process of melting ice, rising seas and intensifying storms have occurred in coastal communities around the world: the South Pacific, Bangladesh and—closer to home—New Orleans. Scientists predict that the worst is yet to come. The rising oceans may swallow some lands forever. By the turn of the century, the map of the world may need to be redrawn and a Category 4 hurricane could drown much of Washington, D.C. in 15 feet of water.

A comet is imagined to strike the Earth and cause major devastation.

The possible effects of extreme climate changes around the world in a short period of time are examined. Included: how drought altered the Mayan civilization.

This special-edition episode examines what happened in the 1906 San Francisco earthquake and its effect on San Francisco and looks at the destruction if it were to happen again today.

The possibility of a tornado hitting downtown Chicago is the scenario. Included is an examination of the 1967 twister that hit the suburb of Oak Lawn.

The New Madrid Fault could reawaken at any time and destroy St. Louis, Missouri and Memphis, Tennessee, like the New Madrid Earthquake of 1811-12.

Mount Rainier is a ticking time bomb that could dwarf the 1980 eruption of Mount St. Helens, sending massive lahars and mudslides toward the Seattle-Tacoma metropolitan area.

How a major tornado would impact Dallas is examined by studying the effect of a twister that struck Oklahoma City on May 4, 1999, killing 43 people and causing $1 billion in damage.