Analysis - Earthquakes reinforce need for planning

Apr 18, 2008

As windows rattled, beds shook and bricks tumbled, Midwesterners inevitably reacted with shock, fear and even wonder at Friday’s series of earthquakes centered in southeastern Illinois and felt across a dozen states.

about the author
William Allen teaches science journalism at the University of Missouri at Columbia and leads the Agricultural Journalism Program. He reported on science, medicine and the environment for the St. Louis Post-Dispatch from 1989-2002.

Just as inevitably, the seismic activity in the Wabash Fault Zone will bring a wave of public discussion about whether Missouri and southern Illinois are in the bull’s eye of an impending “Big One” from the New Madrid Fault -- and whether the region’s buildings and people are adequately prepared.

That discussion will raise important questions, although it’s unlikely to rise to the level of intensity sustained in 1989 and 1990. During those two years, concern about the region’s earthquake threat leapt to a degree rare outside of California, driven by a combination of scientific activism, news media attention, a killer quake in the San Francisco area and a fantastical forecast for a devastating eruption in the Midwest.

New Madrid's history

The New Madrid Fault got its name from the frontier outpost town near the epicenters of a series of major earthquakes in December 1811 and early 1812. The quakes, estimated at better than 7.0 on the Richter scale, damaged buildings as far away as Washington, D.C., and Charleston, S.C. Other significant quakes followed in 1843 and 1895.

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On the New Madrid Fault

On the recent earthquakes

That record, plus the constant chatter of smaller temblors, are behind today’s concern among scientists, engineers, public officials and others responsible for constructing safe buildings, bridges, pipelines and other elements of infrastructure.

These are their questions:

  • When will another large quake strike in the New Madrid Fault?
  • Where will it strike within the fault zone, which covers southeast Missouri, southern Illinois, northeast Arkansas, western Tennessee and western Kentucky.
  • And how far beyond the zone will its ground motion – transmitted by the region’s characteristic bedrock -- rip and tear?

In the 1970s, led by St. Louis University seismologist Otto Nuttli, scientists warned about the quake potential in the New Madrid Fault. Engineers began to publicize the particular vulnerability of thousands of the region’s old brick buildings, especially in St. Louis. These so-called unreinforced masonry buildings were great for withstanding fire. But in the face of an earthquake they were – especially older ones with brittle mortar – ready to pancake.

In the late 1980s, other scientists and engineers picked up where Nuttli and his colleagues left off. Their warnings were perhaps best summarized in a report commissioned by the Federal Emergency Management Agency. Issued in 1990, the report said a daytime New Madrid earthquake of 7.6 on the Richter scale at the northern end of the New Madrid Fault, about 100 miles from St. Louis, would kill some 260 people in St. Louis and St. Louis County, many of them schoolchildren.

The quake would injure more than 1,000 and cause more than $2 billion in damage to buildings. Thousands would be left homeless. Casualties would overwhelm hospitals. Damage to roadways and bridges would slow rescue efforts.

News media stories about such topics, followed by heavy national coverage of the October 1989 World Series earthquake in the San Francisco Bay area, heightened local concern.

Into this mix stepped Iben Browning of New Mexico.

Prophet of doom

Behind a cloud of equations and physics-speak not unlike that of a card-carrying seismologist, Browning, actually trained as a climatologist, issued a startling forecast. He called for a 50-50 chance of an earthquake in the New Madrid Fault measuring between 6.5 and 7.5 on the Richter scale. And he called for it during the first few days of December.

The Browning prediction seeped into the region first through national media and then the local press. The specificity of the predicted time frame captivated many. By November, coverage steadily escalated, as did public anxiety.

Most earthquake scientists were livid that the Browning prediction was given credence. But one key expert, David Stewart of Southeast Missouri State University and Missouri’s official earthquake adviser, backed Browning.

No quake occurred. Browning faded from view. Stewart left the university and his state advisory duties.

Preparedness progress

At the end of the Browning affair, only emergency preparedness officials seemed to see a silver lining. They pointed out that public awareness of the region’s real earthquake threat had grown. More families were taking household safety measures.

Businesses and public institutions were making plans to strengthen their facilities. Engineers in Missouri and Illinois bolstered hospitals and vulnerable bridges. The Missouri Botanical Garden even made giant rubberized seismic shock absorbers part of the foundation of a new building.

And Missouri created its own Seismic Safety Commission to continue the discussion of balancing the needs and costs of preparing.

Public surveys have shown that more Midwesterners than ever agree that the threat is real and that there’s still a need to inch toward awareness and preparedness.

Friday’s event was just the latest nudge in that direction.