Nature's main threat isn't an earthquake

In 1811 and 1812, earthquakes linked to the New Madrid fault in downstate Illinois were so violent that they "made the Mississippi River run backward," according to Southern Illinois University geophysicist Harvey Henson, Jr.

It's a good thing the area within the epicenter of those quakes had not been heavily populated. If so, many people would have been killed or injured.

Yet lives have been lost in more recent earthquakes in Alaska, California and Montana, including 3,000 in San Francisco in 1906.

This should put last week's minor earthquake -- which even today continues to send out aftershocks -- in the right perspective. While we were more intrigued and amused by the slight shaking of the ground that occurred in the suburbs last week, people in states like California dread the next time plates shift in the ground.

Yet we do have something in common with Californians. We aren't spared from a predictable, unstoppable and violent blow from nature. It won't come from deep in the ground, but from high in the sky.

We have entered another tornado season.

Most twisters occur between April 1 and June 30, according to the Illinois Emergency Management Agency.

Last year, there were 22 tornadoes in Illinois. One of them touched down briefly between Wheaton and Winfield. But it caused no injuries or death. In fact, none of those 22 tornadoes claimed lives, and injured only three people.

But tornadoes can strike more frequently -- and viciously.

A record number of tornadoes -- 124 in all -- were reported in Illinois in 2006. Fortunately, only one person was killed.

That wasn't the case when the storm clouds moved in on Plainfield in 1990. By the time the huge twister had expended all its incredibly violent energy, 29 people had died.

In 2004, Utica was also hit by a powerful tornado. It killed eight people.

The next deadly tornado could descend from the clouds next week, next month, at any time during this season when conditions are ripe for tornado formation. And it could touch down in our downtowns, our backyards.

But the damage from tornadoes, both in loss of life and property, can be limited. It means having severe weather response plans in place in schools and businesses, and taking tornado drills seriously. It means being alert to the weather and taking warnings seriously.

Municipalities would do well to remind residents how their tornado warning systems work, what a siren means and what action residents should take when they hear them.

The Midwest does have fault lines that can trigger earthquakes far more serious than the one we felt last week. But the most immediate threat to our lives, when nature turns wicked, is the tornado. Just as we can safely predict the possibility of tornadoes, we are also blessed with the ability to keep ourselves as safe as we can from them.