Natural Disasters: Top 10 U.S. Threats

This photo of Earth from the International Space Station was taken by NASA astronaut Ron Garan, who has been blogging about the planet's beauty on his website Fragile Oasis. This image, taken on April 15, 2011, was Garan's first photo sent via Twitter. (Image credit: NASA via Ron Garan/Astro_Ron)

Government officials are evaluating and revising disaster plans around the United States in the wake of Hurricane Katrina, just as they did after the Sept. 11 terrorist attacks. While war and automobiles kill more people than nature, find out what natural disasters top scientists' worry lists.

Total Destruction of Earth

Despite Rumors, Black Hole Factory Will Not De

Okay, so nobody is spending too much time worrying about what to do if the planet is annihilated, but at least one person has seriously pondered whether and when it could happen. From being sucked into a black hole to being blown up by an antimatter reaction, there are scientifically plausible risks of an event that would render this whole list moot.

Gulf Coast Tsunami

Misawa, Japan, cleanup by U.S. Navy — A sailor assigned to Naval Air Facility Misawa hauls debris during a cleanup effort at the Misawa Fishing Port, located in the eastern Aomori Prefecture in the T?hoku region of northeastern Japan. More than 90 sailors from Naval Air Facility Misawa volunteered to help Misawa City employees and members of the community begin to clean up after the 9.0-magnitude earthquake and tsunami struck the area. (Image credit: U.S. Navy photo by Mass Communication Specialist 2nd Class Devon Dow/Released)

A fault line in the Caribbean has generated deadly tsunamis before. Up to 35 million people could be threatened by one in the not-to-distant future, scientists say.

East Coast Tsunami

Subway Flooding: A Hidden and Neglected Risk

It seems no coast is immune to the threat of tsunami. For the Eastern United States, the likeliest scenario is waves kicked up by an asteroid splashing into the ocean. Astronomers already have their eye on one rock that could hit in the distant future, but the cosmos could hold a surprise, too.

Heat Waves

Heat waves kill more U.S. residents than any other natural disaster. As many as 10,000 people have died in past events. As urban areas get hotter, electricity systems are strained and the population ages, the risk grows.

Midwest Earthquake

earthquakes, seismology, new madrid earthquakes, great central us shakeout, earthquake drills, midwestern earthquakes, us geological survey, plate tectonics, geology — A map of the New Madrid and Wabash Valley seismic zones shows earthquakes as circles. Red circles indicate earthquakes that occurred from 1974 to 2002 with magnitudes larger than 2.5 located using modern instruments. Green circles denote earthquakes that occurred prior to 1974. (Image credit: USGS.)

It has been nearly two centuries since a series of three magnitude-8 quakes shook the then-sparsely populated Midwest, centered near New Madrid, Missouri. Another big one is inevitable. Now the region is heavily populated, yet building codes are generally not up to earthquake snuff. What?s more, geology east of the Rockies causes quakes to be felt across a much wider region. Shelves would rattle from Boston to South Carolina. Some homes along the Mississippi would sink into oblivion.

Supervolcano

Yellowstone National Park's Old Faithful erupting a column of steam and superhot water. (Image credit: dreamstime)

It probably won't happen for hundreds or possibly even millions of years, but nobody really knows when Yellowstone will blow again, destroying life for hundreds of miles around and burying half the country in ash up to 3 feet (1 meter) deep.

Los Angeles Tsunami

Japan tsunami wave heights — The 8.9-magnitude (which may have been upgraded to a 9.0) earthquake that struck Japan triggered tsunamis across the region. Here, results from a computer model run by the Center for Tsunami Research at the NOAA Pacific Marine Environmental Laboratory show the expected wave heights of the tsunami as it travels across the Pacific basin. The largest wave heights are expected near the earthquake epicenter, off the coast of Sendai, Honshu, Japan. The wave will decrease in height as it travels across the deep Pacific but grow taller as it nears coastal areas. In general, as the energy of the wave decreases with distance, the near-shore heights will also decrease. For example, coastal Hawaii will not expect heights of that encountered in coastal Japan, according to NOAA. (Image credit: National Oceanic and Atmospheric Administration (NOAA))

An earthquake fault just off Southern California could generate a major quake and a $42 billion tsunami that would strike so fast many coastal residents would not have time to escape. Add to that the unprecedented destruction from the earthquake's shaking, and the situation would be reminiscent of Hurricane Katrina.

Asteroid Impact

Asteroid & Earth — Some researchers theorize that chemical building blocks brought to Earth via comets, asteroids or meteoroids may have set the stage for life on Earth. (Image credit: Don Davis)

Scientists can't say when the next devastating asteroid impact will occur. Odds are it won't be for decades or centuries, but an unknown space rock could make a sucker punch any time. Many experts say planning to deal with a continent-wide catastrophe should begin now.

New York Hurricane

2010 Hurricane Season Sped Up — See all the Atlantic hurricanes from last year swirl by in just a few minutes. (Image credit: NOAA)

Major hurricanes have made direct hits on the boroughs before, but the interval between them is so long that people forget, and officials fear they might not take evacuation orders seriously. The larger problem: It would take nearly 24 hours to make a proper evacuation of New York City, but hurricanes move more swiftly as they race north, so real warning time could be just a few hours.

Pacific Northwest Megathrust Earthquake

A California highway knocked awry by a 7.3-magnitude earthquake near Landers, California. Credit: Southern California Earthquake Data Center — A California highway knocked awry by a 7.3-magnitude earthquake near Landers, California. (Image credit: Southern California Earthquake Data Center)

Geologists know it's just a matter of time before another 9.0 or larger earthquake strikes somewhere between Northern California and Canada. The shaking would be locally catastrophic, but the biggest threat is the tsunami that would ensue from a fault line that's seismically identical to the one that caused the deadly 2004 tsunami in Indonesia.