Unusual Astronomical Lineup Prompts Tidal Force Worries in Midwest

All sides agree on one thing: Watch your step next Dec. 2.

Because of an unusual lineup of heavenly bodies around that date, some forecasters are raising the specter of coastal floods--and, perhaps, the worst earthquake in American history.

Scientists strongly disagree as to the potential for disaster, but there is no mistaking what will be happening in the sky. Five forces that affect tides--three involving the moon and two of the sun--will reach peak strength at about the same time.

“I think the public has a right to know about any danger of this kind that can catch them unaware,” said Fergus J. Wood, an astronomer and meteorologist who has spent much of his career studying the relationship of astronomical configurations to coastal flooding.

A New Mexico climatologist and volcanologist, Iben Browning, recently set off a media storm in southeastern Missouri and surrounding states by saying that a killer earthquake could be triggered at the New Madrid Fault. The well-known geological rift is thought to be overdue for activity.

“There is going to be high tidal force Dec. 2,” Browning said. “If the earthquake gun is loaded, it will go off.”

Browning’s conclusions have been widely challenged by other scientists, but they have had an electrifying effect on residents of several states.

Missouri and Arkansas officials say that public concern influenced their decisions to conduct long-planned earthquake-training exercises during that period. An official in Illinois, whose southern region could be affected, said that such exercises also are under consideration there.

Kentucky, Mississippi and Tennessee are proceeding with previously planned exercises in October. Indiana will conduct drills in November.

“We aren’t taking Browning’s statements lightly,” Kelly Stemnock, head of Indiana’s State Emergency Management Agency, said. “On the other hand, we’re not crying wolf. We’re not treating Dec. 2 or 3 any differently from any other day.”

Many other scientists concerned with tides and earthquakes say that Browning’s remarks caused needless anxiety. They disagree as to the tide-pulling power of the astronomical lineup.

“When all these characteristics are in phase, you’ll have tides that are a little larger than normal,” Jack Fancher of the National Oceanic and Atmospheric Administration said. “But they’re not major tide changes. I don’t see there is anything to alarm people about.”

Wood emphasized that he is not flatly predicting catastrophic floods on Dec. 2. In fair weather, he said, such higher-than-average tides are generally harmless. Trouble, all agree, is possible when the highest tides coincide with hurricanes or other storms with high winds.

“Three to five days in advance, you should start looking at weather forecasts,” said oceanographer Reinhard E. Flick of the California Department of Boating and Waterways. “If there are storms on the horizon, then you can start worrying about sandbagging and plywooding and evacuating, perhaps. There’s no question there could be danger.”

The scientific jury is still out on whether earthquakes are set off during periods of unusually high tides.

“There is every reason to believe tides may be a trigger for earthquakes,” said Thomas H. Heaton of the U.S. Geological Survey. “Theoretically, it’s entirely possible.”

But studies undertaken by various researchers, including Heaton, to prove a correlation have had mixed results. No one in the mainstream academic community has yet been able to predict earthquakes based on tide tables.

Like Wood, Browning is careful not to claim he can reliably predict disasters but, he said, he used tidal-force data to forecast the 1980 eruption of Mt. St. Helens volcano, of killer earthquakes in Nicaragua in 1972 and Indonesia in 1979, and last October’s earthquake below San Francisco.

Earthquake experts have long warned that the New Madrid Fault is a geological time bomb. A quake of near magnitude 8 occurred there during the winter of 1811-12. The tremors devastated New Madrid, Mo., and were felt as far away as the East Coast.

Destruction from such an earthquake would be vastly worse today, experts warn, because of the proximity of Memphis, Tenn., St. Louis, and many small and medium-size towns. Seismologists and engineers have estimated potential losses from a magnitude 8 or larger earthquake along the New Madrid Fault at tens of billions of dollars and thousands of deaths.

Many scientists question Browning’s concentration on Dec. 2. Harvey Barton, superintendent of the South Mississippi County School District in Missouri, is taking no chances. He has designated Dec. 3 and 4 to be teacher-training days.

If the school board approves, classes will be canceled on those dates.