By Harold Henderson
Monday morning, December 16, 1811, on the Mississippi River in the village of Little Prairie, Missouri Territory. The ground rocked and rolled so hard it knocked people down. Sixteen-year-old Ben Chartier had been hanging around his family's cabin door, where his mother was having a smoke. "The sky turned green, and then it shook hard. My father and my cousins ran and turned the hogs out. The ground burst wide open and peach and apple trees were knocked down and then blowed up."
James Fletcher, another resident of Little Prairie, later said some cracks were "eight and ten feet wide, others of less width, and some of considerable length." They started filling with water, and within 15 minutes the town was awash.
George Roddell, a miller in the town, saw one end of his house settle several feet and his grain mill fall down. Swampland next to the town rose up and "became dry land." His family tried to run away, but a large crack blocked their path. "There was not perhaps a square acre of ground unbroken in the neighborhood," according to the version of Roddell's story published in the Pennsylvania Gazette the following February. "In about fifteen minutes after the shock the water rose around them waist deep."
Roddell led the townspeople through the chilly water. They waded west, away from the river, looking for high ground. The water was muddy, and sometimes they stumbled into crevasses they couldn't see. "As they proceeded, the earth continued to burst open, and mud, water, sand and stone coal, were thrown up the distance of 30 yards--frequently trees of a large size were split open, fifteen or twenty feet up. After wading eight miles, he came to dry land."
Thursday afternoon, November 9, 1995, overlooking the Mississippi River from the William Campbell farm near Dyersburg, Tennessee. Over the years David Stewart has worked as a geologist, preacher, author, natural-childbirth activist, consultant, and entrepreneur. Most recently he's been in the business of reminding anyone who will listen that the big quake of 184 years ago will be back some day. And when it comes it could do more than just rattle your dishes off the shelf.
Campbell uses the seemingly solid sand-and-gravel hillside Stewart's standing on as a gravel pit. For Stewart it's a ready-made earthquake laboratory, where he can re-create Little Prairie's nightmare in miniature. He stamps his foot on the ground again and again. The ground begins to shake like jelly where he stamped. Water seeps up out of it, and his feet begin to sink. He stamps one last time, then jumps away a few feet. "Usually you get quicksand," he says. "But under the right saturation conditions you can even get quick gravel." Behind us were just the right conditions--a clear-cut hillside of porous loess soil and gravel, all resting on a layer of impermeable clay. The groundwater where we were standing was under pressure and looking for a way out. Stewart's stamping helped the water rise up and "liquefy" the soil.
In an earthquake the vibrations would come from below, but the result would be the same. You might assume that the 1811 quake simply sank Little Prairie into the river. Not so, says Stewart. The ground on which it stood shook so hard it liquefied.
Stewart looks across the Mississippi River toward Caruthersville, Missouri, 15 miles away. Tiny against the sunset stands a ten-story blue-and-white grain elevator, the landmark closest to where the village of Little Prairie stood before it vanished in 1811. He says, "It wasn't the Mississippi River that drowned Little Prairie."
The biggest earthquakes ever to hit what are now the Lower 48 were centered within sight of that gravel pit, along the Mississippi River where Illinois, Missouri, Arkansas, Kentucky, and Tennessee converge. Between December 16, 1811, and February 7, 1812, a scattered frontier population of Indians, Frenchmen, and Americans bore the brunt of five separate shocks now estimated at between 8 and 8.8 on the Richter scale, plus countless smaller quakes. (Little Prairie was just 40 miles northeast of the center of the first big one.) Most historians say there were few deaths. Stewart counts Indians and river boatmen and thinks 500 is a low estimate. Nobody really knows.
The bigger shocks traveled far. On January 23, 1812, one quake--not the strongest--felled chimneys in Cincinnati, buckled sidewalks in Baltimore, rang church bells in Boston, and caused the North Carolina legislature to adjourn in confusion. But nobody in the populous east knew what the shaking signified or where the quake was centered. And few people lived where it hit hardest, in and around Missouri's "boot heel." In 1811 Fort Osage, near present-day Kansas City, was the westernmost white settlement in the U.S., Chicago, a frontier fort and trading post with a population of 40, was smaller than Little Prairie.
The few people on the spot had no cameras, no radio, no TV, no telephones--no way to quickly get the word out. Most of the earthquake's survivors left the area as soon as they could. "If we do not get away from here," wrote one man in a family journal, "the ground is going to eat us alive." Those with firsthand knowledge of the New Madrid quakes--named for a small town north of Little Prairie that survived--soon dispersed. So it happened that the greatest geological event in the history of the midwest was almost completely forgotten.
Today smaller quakes in California get all kinds of notice. Not only are they in more populous areas, but in some places you can actually see the fault lines at the surface. Rocks in the midwest lie well underground, so here earthquake features tend to get washed away or overgrown.
The general public's ignorance of the New Madrid quakes was long mirrored among professionals. In 1988 Stewart talked with the director of an earthquake-preparedness project in southern California "whose entire professional career," Stewart later wrote, "had concerned earthquakes. Yet, he had never heard of the New Madrid Fault or of the New Madrid earthquakes of 1811-12."
Forgetting an earthquake is easy--but dumb. You don't need to know a crevasse from a hole in the ground to realize that where the earth has shaken once it will do so again. It's just a matter of time.
Some of that ignorance was undone by the earthquake scare of December 1990, when an ambiguous prediction from reclusive market consultant Iben Browning generated a media circus but no actual quake. Now Stewart and his collaborator Ray Knox, of Southeast Missouri State University, are trying to find some middle ground between history and hysteria. They've studied, identified, photographed, and described hundreds of earthquake signs still visible in the New Madrid area--if you know where to look. They call their work "morphoseismology" (the study of landforms created or modified by earthquakes) or, less formally, "recognizing earthquake features for fun and profit." And they've written three folksy, humorous books to make sure we don't forget again:
The Earthquake That Never Went Away: The Shaking Stopped in 1812, But the Impact Goes On (1993, Gutenberg-Richter Publications, $15) is an album of earthquake photos with extensive captions, an armchair travelogue of the fault zone marketed as a kind of do-it-yourself after-dinner speaker's kit (color slides are available for an additional $165).
The Earthquake America Forgot: 2,000 Temblors in Five Months . . . And It Will Happen Again! (1995, $30) covers the history of the quakes themselves and their historical context in panoramic detail, including Tecumseh's rebellion, the comet of 1811, Napoleon's march on Moscow, the reign of Pharaoh Ramses II, and the Little Ice Age. Civil engineering professor Teresa Crespellani of Florence, Italy, describes it in a blurb as "science presented in the style of fiction."
Most recent is The New Madrid Fault Finders Guide (1995, $17), which offers a milepost-by-milepost guide to one main trip and six side trips through the quake zone. The last page is a diploma-style "Certificate of Achievement in Fault Finding."
All the books come with an "exclusive earthquake hazard warranty"--if they're damaged in a quake the publisher will replace them free. They're available by mail order (800-758-8629, "the toll-free number with an 8.8 in the middle"), in bookstores from Saint Louis south, at the KOA campground off I-55 between Portageville and Hayti, and at Duckies truck stop on I-55 in Steele.
Doesn't sound much like Physical Geology 101, does it? But the authors both have PhDs in geology. Stewart specializes in seismology and hydrology, Knox in geomorphology. Their work is unique because they don't have much respect for professional decorum and orthodoxy. Their mainstream colleagues in earthquake studies characterize Stewart in particular as a gifted popularizer who knows enough to distinguish scientific fact from speculation, but who often neglects to do so if the speculation makes a better story. "Large parts of [The Earthquake America Forgot] are unique and valuable," says Arch Johnston of the Memphis State University Center for Earthquake Research and Information, "and large parts I have real problems with."
"We have done our research and drawn our conclusions without regard to whether or not they agree with previous sources," Stewart and Knox write in the introduction to The Earthquake America Forgot. "We have challenged more than a few scientific and historical dogmas. We hope our new paradigms will all be taken, as we have written them, in good faith and good humor."
They published the books themselves, under the name Gutenberg-Richter Publications of Marble Hill, Missouri. "That way you have ultimate editorial control," Stewart says. "We wanted to be sure we got said what we wanted said. A publisher might send this [manuscript] out to a seismologist who would say, "Change this and this."' (Still, the books might have benefited had a publisher inflicted a stern copy editor on the authors.) They've sold close to 6,000 copies of the three books and, according to Stewart, are close to breaking even on their investment of more than $70,000.
"Colleges and schools all over the country are using our books," says Knox, though not his department at Southeast Missouri State (SEMSU). Asked why, he passes the question to Stewart, saying, "I might get too emotional." Stewart pauses a minute and comes at the question sideways. "We've got a guy in our [geoscience] department [at SEMSU] who's doing work in Russia. That's exotic. Well, Dr. Knox and I realized that we were living in an exotic place. If we were coming here from New York [to study the fault zone], it'd be great."
But there's more to both men's reluctance to answer the question. Stewart was dismissed from SEMSU's faculty in the spring of 1993. He believes he was fired because he didn't join his fellow seismologists in condemning Iben Browning for what he said about a possible earthquake in 1990. "They had to break every rule in the book to get rid of me," Stewart says. He's since sued the school for libel, slander, and breach of contract, and the case is now in the discovery stage in the Missouri state court.
Stewart says he's proud of the work he and Knox have done. "We've made discoveries, we've filled gaps. And we were able to do it without megagrants from the government."
From the journal of George Heinrich Crist Sr., Livingston County, Kentucky, Monday, December 16, 1811: "There was a great shaking of the earth this morning. Tables and chairs turned over and knocked around--all of us knocked out of bed. The roar I thought would leave us deaf if we lived. . . . It was still dark and you could not see nothing. I thought the shaking and the loud roaring sound would never stop. You could not hold onto nothing. Neither man or woman was strong enough--the shaking would knock you loose like knocking hickory nuts out of a tree. I do not know how we lived through it. None of us was killed--we was all banged up and some of us knocked out for awhile and blood was everywhere."
The history of the New Madrid earthquakes can be traced back 600 million years to a time when there were no fish, no insects, no land animals. Trilobites were the pinnacle of evolution, and all the continents were stuck together in a single land mass. During this distant era what we now know as the middle Mississippi River valley almost became an ocean. The rocks under it began to pull apart, but then were pressed together again.
"If those forces would have succeeded in breaking North America along that zone, New Madrid would have been on the Atlantic coast and the Eastern U.S. would have been part of Africa," writes Knox in a chapter of the Fault Finders Guide titled "Half a Billion Years in Five Minutes." "Although the continent did not separate there, a weak zone was created that persists to the present where quakes occur. Scientists call it a "failed rift."'
We're used to quakes and volcanos being at the edges of tectonic plates, as they are around the Pacific Rim. But New Madrid lies above a weak zone in the middle of such a plate, something that intrigues geologists. Since that first failed rift, the area has been pulled apart, then pressed together again; for the last 100 million years or so it's been under compression. Pushed or pulled, the zone is weak. Whenever the pressure gets too great, the rocks underground slip and slide along the network of faults. Stewart and Knox define the New Madrid seismic zone as the area that shook the most in 1811-'12. That's a band 50 miles wide and running from northeast Arkansas to the Cairo area in southern Illinois. When Mother Earth makes small adjustments in the zone, her tenants may suffer. Then again, as we will see, they may just get themselves a bottomless garbage dump.
Roy Proctor farms the bottomland within sight of Interstate 55, the highway that bisects the Missouri boot heel north to south--a highway Stewart and Knox would like to name "earthquake alley." Back in the fall of 1973 the Mississippi River had stood at record height for months, raising the water table and making some of Proctor's ground mushy. He and his father were driving a big combine across a seven-acre patch of sand when the machine's vibrations liquefied the saturated ground the way a minor earthquake might. The combine's right front wheel sank into the ground and stuck there.
The two men brought one tractor to pull it out, then another. It didn't budge. Hours later they tried laying down two eight-foot railroad ties to give the combine firm footing to roll onto. It worked, but as they were pulling the machine out the ties shot from under the wheels and disappeared into the sand. They haven't been seen since. All things considered, Proctor says, "I'd just as soon keep 'em there."
Everyone knows that earthquakes shake the ground and knock down houses. Few realize that under the right circumstances they can turn the ground to jelly and then to mush and then to quicksand. Liquefaction, as Stewart and Knox explain it, can be caused by a quake ("seismically induced liquefaction" or SIL), by water saturation ("hydrologically induced liquefaction" or HIL), by physical pounding ("mechanically induced liquefaction" or MIL), or by some combination. Three possible causes, one effect. When Stewart stamped the ground in the gravel pit and when Proctor's combine vibrated over the sand patch, they mimicked the New Madrid quake. "Liquefaction," write Knox and Stewart in the Fault Finders Guide, "is more likely to occur if the sediment consists of sand or silt, is loosely compacted, and if the spaces between grains are filled with water." The longer a quake lasts, the likelier liquefaction is. "For strong earthquakes 6.0 or greater, liquefaction can occur at the epicenter or for considerable distances--more than 100 miles away."
The seven-acre sandy patch on Proctor's farm was actually a sand boil from the 1811-'12 quakes--a place where saturated liquefied sand had forced its way up through nonliquefied soil. Such places, abundant in the New Madrid area, are easiest to see in farm fields and from the air: circular patches of light-colored sand in winter, circular patches of puny crops or uncultivated land in summer. All have direct connections to the water table not far underground. If they get too wet or shake too much they can do spooky things. The fate of Proctor's railroad ties is far from unique.
Some sand boils form small, intermittent "earthquake ponds" that fill from the bottom with clear water that stays cold all summer. In The Earthquake That Never Went Away is a photograph of one such pond in New Madrid. It's swampy and shrubby and had been used as a dump for years before it was filled and covered in 1991. "It seems to work well," Stewart and Knox write genially. "When the water table is rising, liquefaction in the bottom of the pond causes heavy items dumped in the pond to sink and disappear. You can keep putting trash into such holes for a long time and it seems like they never completely fill up." The city of Sikeston routes some of its storm-water drainage into such a place.
"What the users of this site do not realize is that some day, during a major earthquake, that earthquake pond is going to liquefy explosively and regurgitate all the debris it has been forced to swallow all these years. You are going to have old refrigerators, broken radio sets, dismantled television sets, used brick, concrete blocks, rusted buckets, crushed tin cans, bed springs, discarded bathtubs, worn furniture frames, and who knows what else belched back into view. We can only hope no one inadvertently builds a house over one of these buried earthquake ponds."
This pious hope comes too late in some places. All kinds of things in the fault zone--houses, power plants, chemical storage tanks, interstate highway interchanges--have been innocently built on top of old earthquake features such as sand boils and landslides.
In June 1990 Stewart and Knox photographed several big "explosion sand blow craters" on both sides of I-55 just north of milepost 60 for The Earthquake That Never Went Away. In December 1991 they returned to find the explosion crater on the west side covered up: "A wireless cable company from Oklahoma found this piece of real estate to be a suitable location for a transmitting tower," they write. "The tower, equipment building, and receiving dish are all centered over where the explosion crater was seen the year before. . . . This transmission tower is 700 feet tall and exerts a downward force of 300,000 pounds at its base which rests on a small concrete pad only 2 feet thick and 14 feet square. An earthquake, or even a high river stage, could cause this area to liquefy and become temporary quicksand."
The tower is painted in alternating 100-foot bands of red and white. So the authors (with the help of Mark Winkler of the state Emergency Management Agency) dubbed it the "Richter Dip Stick." "For a [quake of] magnitude 6.0, it should sink about half-way up the first red section," they write. "For a magnitude 7.0, it should sink all the way to the white span. For an 8.0 the entire red section and half of the first white section should disappear. For an 8.8, like back in 1812, it would just topple over, lying completely across the Interstate." Stewart and Knox add that they're just kidding of course, since there's no way to tell what would actually happen to the tower. This is one of those things that endears them to the public but not necessarily to others in their profession.
Maybe because Stewart and Knox are native Missourians and not puritanical Yankees, or maybe because they have the geologist's ingrained habit of taking the long view, they're more rueful than angry about the foolish things people do. When we visit the power plant outside Sikeston--built atop a highly liquefiable sand fissure--Stewart says, "Ray and I hope these books will open people's eyes, so that contractors and developers will know. Twenty years ago when they built this power plant they couldn't have hired a geologist who could help them. "Oh, that's just sand--go ahead and build,' without knowing what kind of sand it was and what it meant."
How much does it really matter where you are (or where your power plant is) when a quake of 7 or 8 magnitude hits? A lot, says Stewart.
Water-saturated sand will liquefy, and water-saturated clay will amplify the quake's force. "You're best on bedrock or on dry soil within 50 feet of bedrock. Building on a sand boil is kind of asking for it." I mentioned that most of Chicago's Loop is fill, not bedrock, and not far above the water table. "They're asking for trouble," he said without smiling. According to U.S. Geological Survey estimates, northeastern Illinois was in the "serious damage" area for the 1811-'12 quakes, though the damage was less severe than it was in areas closer to New Madrid, which are labeled successively as "major damage," "destructive," "devastating," and, right at the center, "disastrous."
How do you tell if something's a sand boil? "You can usually make a shrewd guess," says Knox. "The color is maybe a little more orange."
"Sometimes we can spot subtle shades and say that's clay or that's sand without walking across the field," adds Stewart. "One of the great things about being a geologist is that your principal instrument is yourself. For instance, you can taste for clay."
Knox: "And you can check for grain size by biting on them."
Stewart: "A skilled geologist has to calibrate himself."
Stewart started working on the New Madrid books in 1988. "I soon realized that if I did it on my own I was going to make some stupid mistakes."
"Yeah," says Knox, "and I was the first guy you ran into in the hall after that." Their project, which was once supposed to take two years, stretched to seven.
The collaborators are in some ways an odd pair. Stewart is short, tending toward round, and talkative. Knox is tall, angular, and taciturn. Knox, who's 64 and planning to retire this year, has always been a geology professor and outdoorsman. Stewart, 58, has been a Methodist minister, a photographer, and an activist in the natural-childbirth and breast-feeding movements (he and his wife, Lee, have five grown children). He's written seven other books, including Good Fathering & a Successful Career: Can a Man Do Both? and, with his wife, The Childbirth Activists' Handbook. A natural storyteller and glad-hander, he's not an easy person to walk around the town of New Madrid with, because he has to stop and talk to everyone.
Stewart and Knox share the extraordinarily dry sense of humor that professional study of the earth seems to foster. More important, they share a fascination with the fault zone and a stubborn streak. Eyewitness reports from 1811-'12, for instance, state that the water coming out of earthquake cracks was warm. In the past some scientists discounted these reports, in part because no one could figure out how it could have become warm. Knox won't have any of that. "We've had truckers tell us that wet sand shifts around and gets hot enough to steam [from friction]. So we thought, why couldn't that happen underground? Contemporary witnesses reported hot water coming out of the ground. Experts say that must be an illusion due to stress. Baloney! You don't need three college degrees to tell warm water!"
Friday, December 20, 1811, near what is now Osceola, Arkansas. The quakes had already altered the Mississippi River channel, causing banks to cave in and making navigation charts useless. So the crew of the New Orleans--the first steamboat to travel the river, on a run from Pittsburgh to New Orleans--navigated by eye and tied up every night to islands in midstream. That night they stopped at the downstream end of a three-mile-long forested island, listed on the map as "#32." After securing a long hawser to a big tree, the crew went ashore to gather fuelwood. Around 4:30 in the morning there was a strong tugging, but nothing as alarming as the shocks they'd felt upstream.
"At daylight, the next morning, Nicholas Baker, the engineer, was the first on deck," write Stewart and Knox in The Earthquake America Forgot. "Gazing upstream, Island #32 was nowhere to be seen. It first flashed into his mind that the boat had broken loose during the night and they were drifting with the current. But a glance toward the far shore showed that they were stationary. But how could that be? They were in the middle of the river, hundreds of feet from the nearest land.
"The boat seemed to be listing slightly to the north. Baker leaned over the bow to see the mooring rope taut and pulled almost straight down into the murky depths of the river. The top of the tree to which it was tied was barely visible beneath the swirling water. Island #32 had sunk during the 4:30 A.M. temblor, pulling the anchor rope with it." The boatmen had to cut the rope to get away. Stewart and Knox attribute the island's disappearance to "liquefaction and subsidence."
In recent years bulldozers, irrigation water, and fertilizer have made sand boils and explosion craters harder to spot. The bulldozers cover them up. Water and farm chemicals enable crops to grow on less fertile soil. "We may need a historic-preservation movement for some of these features," Stewart says. "Save the Boils!" (Later he says that he and Knox would like to see an Earthquake State Park in the area.)
Other earthquake features are sometimes accentuated rather than concealed by human meddling. Landslides, for instance. The Lomax family's home in the hills near Benton, Missouri, faces a rural road in front and overlooks a wooded pond in back. The hill leading down to the pond contained their septic field, until the relatively small New Hamburg earthquake of September 26, 1990 (4.6 on the Richter scale), centered about six miles away. A few days after that quake they noticed that the leaves in their backyard had collected in lines. The following day there were cracks in the ground. The next day the whole hillside started moving downhill toward the pond, taking leaves, grass, trees, and septic-field piping with it. Now their backyard has a six-foot cliff right behind the house.
Many of the ingredients that go into sand boils also go into landslides: porous, saturated soil overlying a bed of clay well "greased" with water, and a good shake. The Lomaxes' backyard slide apparently owes nothing to the 1811-'12 catastrophe, but the ground conditions were right for a lesser quake to set it off.
Sometimes all it takes is to cut down the trees that are more or less holding the site of a past landslide in place. In the 1970s, across the river and upstream from New Madrid, the city of Hickman, Kentucky, decided to cut down the trees that obscured the view from a scenic overlook on a 200-foot river bluff in town. Nobody knew that the bluff was the result of an 1811-'12 earthquake-induced landslide, but once a piece of land has slid, it's been loosened up and is likely to slide again. Stewart and Knox tell the story in The Earthquake That Never Went Away: "Within a year or two, the slope below the parking lot began to bulge and move. The parking lot started cracking away in pieces. The city moved Magnolia Street a little further from the bluff and reestablished a new area from which visitors could stand and enjoy the view, but that area eventually disappeared too, falling down the cliff into the Mississippi bottoms below. It seemed that every time there was a prolonged period of rainfall or a storm of unusual intensity, more of the bluff would break loose and fall away.
"If you go there and look down over the edge, you will see thousands of rubber tires scattered in the mud below. We don't know where it is written, but somewhere there must be a scripture that says that old tires can stop erosion. Unfortunately, this scripture is false, as the citizens of Hickman can tell you."
Forty-seven people provided appreciative blurbs for The Earthquake America Forgot. They include a building contractor in Idaho, an earthquake engineer in Japan, a registered nurse in Virginia, an Episcopal priest in Minneapolis, the editor of the New Madrid Weekly Record, the former president of La Leche League International in Evanston, and the state of Arkansas' earthquake-program manager. The list is even more interesting for who isn't on it. Not one of the 47 enthusiasts is a professional geologist. "We've been criticized for not publishing in technical journals," says Stewart. "But we felt the public deserved the information. We've tried to be as rigorous as we can, but when we say something everybody can understand it. I've known scientists with kind of shaky research who wrote it up obscurely and got it OK'd. If you write something totally crystal clear you're open to attack."
There's another reason for not publishing in professional journals. Such magazines are peer reviewed, and Stewart and Knox see peer review--intended to ensure meticulous accuracy--as a conspiracy to preserve the status quo, the established paradigm in the profession. Stewart and Knox see themselves as paradigm breakers, heroes of science who introduce ideas too new to be easily accepted through the usual professional channels--such as their findings on the unexpected damage even relatively small earthquakes can do. "If you want to be successful in your profession, you refine a small corner of it," says Stewart. "That's useful, and we're glad people do it. But not everyone needs to."
Stewart was certainly not in step with the profession early in 1990, when Iben Browning said there was a 50 percent probability of a 6.5-7.5 earthquake on the New Madrid fault between December 1 and 5. Browning said that the sun and moon's position on that date increased tidal forces and thus increased the probability that the fault might move, if it were otherwise ready to go. Midwestern state emergency managers asked the U.S. Geological Survey whether they should worry about this, and the National Earthquake Prediction Evaluation Council asked an ad hoc group of 11 geologists who'd studied the New Madrid seismic zone to investigate the matter. They made a detailed report on October 18 of that year and found Browning's prediction to be "without scientific validity."
Stewart says professional seismologists were so angry that an outsider had poached on their turf that "they decided to blister this guy," even though other people had earlier written papers that suggested a correlation between earthquakes and tidal forces. The seismologists got even, as Stewart sees it, by inaccurately describing Browning's carefully qualified statement as a categorical prediction. (But Sue Hubbell's account published in the New Yorker in 1991 portrays Stewart as a strong Browning advocate and the mainstream scientists as seriously trying, but failing, to find merit in Browning's work.) "If I had been willing to discredit the man, I'd still be teaching at Southeast," says Stewart. "But I said, show him some respect."
In their first two books Stewart and Knox pay tribute to Browning for making more midwesterners conscious of earthquakes and the need to prepare for them. But when it comes to the big question--when is the next Big One?--they don't stray from orthodox seismology. In The Earthquake America Forgot, they put it this way:
"1. We are not going to have any great New Madrid earthquakes (8.0-9.0) during our lifetimes or even during our grandchildren's lifetimes.
"2. We will probably have one strong or major quake (6.0-7.9) in our lifetime which has the potential of being the disaster of the century." A shock in the lower end of that range is in fact overdue. The last 6.0-6.9 quake hit on Halloween of 1895, and its estimated repeat interval is only 80 years.
Such a tremor would be felt by most Chicagoans, but would cause slight structural damage to only 0.1 percent of the buildings in Cook County, according to Stewart's estimates in Damage and Losses From Future New Madrid Earthquakes, published by the Missouri and federal emergency management agencies. But Saint Louis could expect "moderate" structural damage to about 5 percent of its buildings, along with "probable" landslides, liquefaction, and electric power and telephone outages.
"3. We will most certainly experience a number of light to moderate tremors (4.0-5.9) which, to a few people, will be quite expensive but will pose no significant threat of injury."
As our car heads off I-55 at the Kewanee exit, Stewart announces, "We're going to see an old friend of Ray's and mine who was here at the time of the earthquakes." The friend proves to be an enormous southern red oak (Quercus falcata) with gnarled limbs, standing alone in a field off Highway 61. As we walk toward it the soil changes from dark chocolate clay to a softer, lighter-colored sand. This sand boil probably almost killed the tree during the quake but saved its life afterward, says Stewart, because the ground wasn't fertile enough to encourage farmers to cut the tree down to plant more corn.
Up close the "witness tree" is larger than it seems from the road--a good five feet in diameter at chest height. It's roughly 300 years old, so it would have been around 100 when the quake hit in 1811-'12. "In human terms, that would be puberty," Stewart and Knox write in The Earthquake That Never Went Away. "After this time, in the life of a tree, they don't get any taller, just fatter, not unlike people. After a long peaceful childhood, this arboreal teenager was suddenly jarred into reality at the peak of its adolescence by the rampages of the New Madrid Fault. Caught in a huge sand boil, sand spewing in the air over its limbs and oozing through the toes of its roots, it is amazing that the tree survived."
The great oak leans a little to the south. "Its limbs have grown in a strange and grotesque manner," said Stewart. "It's as if it was waving its arms and gesturing and trying to tell us something. Every now and then I put my ear up to the bark to hear."
Art accompanying story in printed newspaper (not available in this archive): photographs by Paul L. Meredith.