Earthquake expert weighs in on recent local earthquakes

Small earthquakes, such as the two recorded near Lake Wappapello on Sunday, rarely cause damage. But Missouri was once, briefly, the earthquake capital of America.

Back in 1811 and 1812, a region encompassing Missouri — called The New Madrid Seismic Zone — experienced around 2,000 of the highest-intensity earthquakes ever recorded in North American history.

Things seem to have calmed down since then.

Most of geophysicist Don Blakeman's time is not spent educating regular folks on the science behind earthquakes, but he is articulate and patient when he does. He certainly doesn't spend much of his time focusing on Missouri quakes — there haven't been enough of them.

When he's working, Blakeman is one of the duty seismologists at the National Earthquake Information Center in Colorado, part of the U.S. Geological Survey. Although a scientist, Blakeman's job more closely resembles that of a police officer: His highest priority is protecting human life. Blakeman examines earthquakes all over the world. If he restricted himself to Missouri, he might not have enough to study as earthquakes are uncommon in the Midwest.

The two recent earthquakes in Wayne County, Blakeman said, were not "response quakes," not powerful enough to be of particular concern. Sunday's earthquakes were recorded at 2.2 and 2.4 in magnitude. Missouri (along with all of the eastern U.S.) requires a magnitude 3 or above quake to generate a response.

When asked what has changed in Missouri since 1811, Blakeman said, "nothing."

"There's basically nothing geologically different from that time to now. Those quakes were an anomaly. They have been heavily studied but we're hindered by the lack of science that existed at that time. We just don't have enough scientific information to really understand what happened. But nothing that large has happened for 200 years. I think you have to focus more on the typical situation rather than remote possibility."

Asked about the last time he experienced a "high-stakes, high-jeopardy" situation in Missouri, Blakeman's answer was "never."

"I would never use those words. I would never call a situation 'high-stakes' or 'high-jeopardy.' I work on so many big quakes across the world and I'd guess something like 90-95% of those happen on the boundaries of tectonic plates, like California, Japan, Alaska or places on top of plate margins. Missouri is not on the edge of a crustal plate; it's basically in the middle of the plate."

Still, Blakeman was not willing to completely rule out the possibility of a repeat of 1811 and 1812.

"I suppose there is a very, very tiny chance Missouri could experience that again. It's extremely unlikely but we can't say it's impossible," he said. "No one can predict earthquakes. I can point to a region where an earthquake is likely but I can't tell you the size, location, date and time. The science just isn't there. It's a difficult problem that no one has figured out yet."

Today, we're better at dealing with disasters that come from above, such as tornadoes and hurricanes. Satellite coverage, Blakeman explained, changed the world without doing much for earthquakes.

Satellite technology revolutionized early-warning systems for most major weather events but, "We don't have that same kind of situation with earthquakes. It's a different problem. We can't just look and measure the stresses like you do for weather. You can measure some things about earthquakes, but there are limits. We can't predict earthquakes. Nobody can."

Sunday's earthquakes in Southeast Missouri did not demand Blakeman's attention. The most foundational purpose of his job is to help governments, emergency crews, and people themselves respond to catastrophe. Earthquakes in Missouri, if they happen at all, typically do not pose an imminent threat to human life and property.

His office typically recognizes and reports on U.S. earthquakes less than 20 minutes after they occur.

"When you have a really big and damaging earthquake, a lot of infrastructure is damaged to the point it's difficult for people to report what's happened. They may not be able to request aid. By having seismic information out quickly, we allow rescue to happen quickly," he explained.