Expectations for Charleston's next great unexpected disaster 

A Charleston Guide to the End of the World

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Scott Suchy

The air was thick over Charleston the last night of August 1886. Still recovering from a hurricane that battered the coast one year before and a recent slew of tropical storms, the winds had settled and the city was left to suffer through another humid night. Then at 9:50 p.m. the earth shrugged — letting loose a pressure built up over hundreds of years in the span of a minute. Those 60 seconds that threw a resting city from their beds and sent shockwaves across the nation remain the most powerful earthquake the East Coast has felt in recorded history. And time and the rules of physics only dictate that it will happen again.

Charleston in Ruins

There were rumblings underground in the days leading up to the 1886 quake, although without the gift of foresight, these minor tremors served as little more than brief distractions from the heat and the local baseball team's losing season. The first of these foreshocks, as they are now called, was felt in Summerville on the morning of Aug. 27. Less than 24 hours later, another tremor managed to rattle the windows in Charleston homes, with minor shocks counted throughout the day in Summerville. Then came the night of the great quake.

In 1886 a 7.3 magnitude earthquake struck Charleston - U.S. GEOLOGICAL SURVEY
  • U.S. Geological Survey
  • In 1886 a 7.3 magnitude earthquake struck Charleston

At 10 minutes to 10 p.m., with much of the city already in their beds, the sound of rumbling began to grow in intensity. At first, the sound resembled that of a roaring freight train careening down Broad Street. Then the buildings began to shake and crumble. Clouds of dust and rubble filled the streets as men, women, and children fled their failing homes. The first and most violent tremor lasted for 60 seconds, followed by aftershocks that continued throughout the night.

When the dust finally settled, firsthand accounts of the quake describe townsfolk huddled together at street corners joined together in prayer. At the City Jail, inmates hurled themselves against the bars as the building began to shake. A police captain fired at the charging crowd in an effort to keep them from the door.

All across the city, many began to pull the dead and wounded from the rubble. As with many casualties who chose to leap from their windows, a woman jumped from her second-floor bedroom at the corner of Wentworth and Meeting streets, severely injuring her spine. Falling bricks and toppled walls claimed the lives of many attempting to flee their homes, such was the case with a young chemist by the name of Mr. R. Alexander. Crushed to death by a crumbling wall in his Meeting Street boarding house, it was reported that Alexander had just purchased a small pleasure yacht, taking his first and last voyage earlier that evening. In total, the quake resulted in 60 to as many as 110 deaths.

The violent shaking extinguished many of the city's gaslights, but an orange glow could be seen across the skyline as various fires began to grow. A toppled lamp inside a Blake Street home was the cause of one of the earliest fires. A large blaze at the corner of Vanderhorst and King streets burned for two hours before the fire department could manage to douse the flames. Homes at the southeast corner of George and St. Philip streets were among those completely destroyed by fire. In what is perhaps the lone stroke of luck for the people of Charleston that night, there were no winds to carry the flames. By 1:30 a.m., most of the fires had been doused, save for a lingering blaze that continued to burn near the intersection of King and Broad streets.

Badly damaged, the hands of the clock atop St. Michael's Church hung frozen at the time of the first shock. The city's parks filled with those unwilling to return to their damaged homes as the aftershocks continued. Old rugs, shawls, and carpeting was salvaged to assemble tents. Six hundred people camped out in White Point Garden, with another 600 in Washington Square and 1,000 estimated to have resided in makeshift structures in Marion Square.

The quake severed communications between Charleston and the outside world. Telegraph wires littered the streets, and damaged tracks halted trains into the area. Over the following weeks, as the city began to rebuild, the true scope of the Charleston quake was discovered. The initial shocks, beginning in Summerville, were felt up the East Coast. One dispatch estimated that the Charleston quake resulted in $100,000 worth of damage in New York City. Meanwhile, by late September, South Carolina newspapers began to advertise discounted rates for round-trip train tickets for a chance to see Charleston in ruins. Ever the tourist destination, these two-day trips catered to those "wishing to see the terrible havoc in Charleston ... at a very small expenditure of time and money."

Risk Assessment

For Steven Jaume, associate professor at the College of Charleston's department of geology and environmental geosciences, the first quake to which he had a real responsibility to assess came during his time as a postdoctoral fellow at the University of Nevada Reno. Just after 5 a.m., he was awoken when his closet door began rattling. He says that with an earthquake, you don't get an opportunity to sit down and plot what you'll do next. The first task is to figure out where the earthquake is actually occurring and plan accordingly. Support needs to be transferred to the areas most heavily affected. While rumblings may be far-reaching, the epicenter is of utmost concern.

More than a century removed from the 7.3-magnitude quake of 1886, the next major tremor to hit the Lowcountry is less a question of if and more a matter of when. Even today, researchers are still looking for answers regarding the specific causes behind the area's history of major seismic activity.

"The question — the sort of thing that me and my colleagues are always trying to figure out — is why here and not other places up and down the East Coast that have the same geologic history," says Jaume. "We don't know. That's the question: Why here and why not other similar places?"

SOURCES: HOSSEIN HAYATI AND RONALD D. ANDRUS; CLEMSON DEPARTMENT OF CIVIL ENGINEERING; NORMAN LEVINE AND THE LOWCOUNTRY HAZARDS CENTER
  • Sources: Hossein Hayati and Ronald D. Andrus; Clemson Department of Civil Engineering; Norman Levine and the Lowcountry Hazards Center

According to Jaume, the exact nature of the coast's fault system is not completely known because researchers haven't seen any recent activity on the scale of the 1886 quake to measure more precisely. But even though questions remain regarding the underlying nature of the 1886 quake, the area's history of seismic activity and larger quakes still provides guidance for emergency planners.

"We know that there was something in the 1650s. We know there was something in 1886. We know that we get certain larger things every 200 to 250 years. We know that there's a certain size that comes in at about 125 years," says Norman Levine, director of the Lowcountry Hazards Center at the College of Charleston as well as the director of the Santee Cooper GIS Laboratory and the S.C. Earthquake Education and Preparedness Program. "The really big ones, which could have been the 1886 event, happen on average somewhere between 250-550 years. But just as we had an earthquake at 4:24 a.m. this morning, doesn't mean that there isn't constant earthquake activity."

Working alongside Jaume, Levine provides scientific guidance to state and local emergency management groups. CofC's Hazards Center is actually one of three major research institutions across South Carolina that focus on natural threats. Rounding out the trio are Clemson's Strom Thurmond Institute that specializes in economic effects and USC's Hazards and Vulnerability Research Institute, which assesses social vulnerability.

Part of Levine's responsibilities include training others to utilize HAZUS, the software used by FEMA to model the potential damage that may result from certain natural disasters. A 2016 HAZUS report released as a part of South Carolina's emergency management plan shows just how devastating a seismic event on the scale of the 1886 quake would be for the state.

Using data from the 2010 Census, the HAZUS report estimates that more than 4 percent of buildings across South Carolina would be damaged beyond repair, including 13 hospitals, 170 schools, two emergency operations centers, and 30 fire stations. Of the 83,961 buildings experiencing complete damage, more than half would be single-family homes. This projection becomes even more troubling when considering a recent report by the Post and Courier stating that less than 10 percent of South Carolina residents carry insurance to cover earthquake damages.

During the 1886 earthquake, Charleston's brick buildings and those constructed on infill were especially hard-hit when compared to wood-frame structures and anything built on solid ground. With its large supply of historic structures and buildings constructed atop former marshes and artificial fill, Charleston finds itself even more vulnerable to damage.

"Brick masonry is dramatically heavier than wood. That's the most important reason. Seismic forces are a direct function of the building weight. In addition, the mortar in many brick masonry buildings has lost its binder, so it no longer provides much adhesion," says Craig Bennett, president and structural engineer at Bennett Preservation Engineering. "That's basically saying the mortar has turned to sand. The binder or the glue that holds the grains of sand together and actually helps adhere the bricks to each other has to some degree washed out in many buildings, so what you have left is sand. That's not 100 percent the case, but it's far from uncommon."

U.S. GEOLOGICAL SURVEY
  • U.S. Geological Survey

Bennett recalls sitting in his third-floor office in Charleston when a quake struck Virginia in 2011. Although those working in the floors below failed to notice the shaking, Bennett remembers his chair rocking from the far-off quake. He soon received a call from Washington, D.C. asking for his expertise in repairing what he describes as a "secure historic guesthouse that happens to be in the 1600 block of Pennsylvania Avenue."

As for the vulnerability of unreinforced brick buildings — of which there are many in Charleston — Bennett points out that "You can compress bricks all day long, and they resist it very well. They have lots of compression capacity. But tension, very little. You can't pull on bricks or a brick wall without breaking it. So modern masonry, which is generally concrete block, we call it CMU (concrete masonry units), is reinforced in South Carolina and other seismic zones."

Severed

Continuing with South Carolina's HAZUS projections, more than 2,000 highway bridges across the state will suffer at least moderate damage during a repeat of the 1886 quake. In working with emergency managers, Norman Levine helps determine which areas will become cut-off from the rest of the state and how to position resources accordingly.

"There are some huge challenges in this region. Part of the reason is we are the Lowcountry. This area has some 700 bridges in the greater Charleston region, greater than 700. All of those bridges are built on, normally, some form of let's just say less-than-stable land," says Levine. "At least parts of them or ramps to them are built on infill and these sorts of things can be shaken badly. We could be looking at seeing a number of completely disconnected populations after a big event down here. So there's been a lot of planning for how that goes on."

A man sits by one of the many sinkholes created by the 1886 earthquake - U.S. GEOLOGICAL SURVEY
  • U.S. Geological Survey
  • A man sits by one of the many sinkholes created by the 1886 earthquake

Facing another 7.3-magnitude quake in Summerville, an estimated 166,675 households across South Carolina will be without water. More than 94,500 will remain that way a week later. Of the 213,063 households that lose power, more than a quarter will continue to live without electricity one month later. Even 90 days following the quake, 1,341 households will remain in the dark.

One contributing factor to the destruction of underground infrastructure is what experts refer to as liquifaction. As the ground quakes and sediment mixes with water, certain areas can take on the characteristics of quicksand. This can result in landslides and sandblows, which resemble geysers of sand that may open large fissures in the earth. Accounts following the 1886 quake report columns of mud erupting along Beaufain Street and jets of water shooting from crevices opened up across Charleston and Summerville.

"All these sediments liquefy. The pipes start moving underground. They all break, and suddenly you've got no water and no toilet in tens of thousands of houses," says Jaume. "That's a thing that we would face for another significant event that really isn't comparable to 1886."

With almost 94,000 households displaced due to a 7.3-magnitude quake, 62,464 South Carolina residents would seek temporary relief in public shelters. The HAZUS simulation offers three main scenarios when considering the number of casualties that may result from the quake — projecting results of the main tremor striking at 2 a.m., 2 p.m., and 5 p.m. Of these three possibilities, the greatest death toll would result from a midday quake, which would leave 2,877 South Carolinians dead and another 1,553 with life-threatening injuries. While the 1886 quake serves as the worst-case scenario for emergency planners, Jaume warns that even smaller earthquakes could prove devastating for the Lowcountry.

"You don't need a big one to ruin your day. A medium one will still ruin our day. People keep focusing on 1886. Statistically speaking, the next one that you are going to remember for the rest of your life is going to be something more on the moderate size," he says. "You'll be surprised twice that day: Once when the earthquake occurs, because you're probably not going to get a warning, and second when you see me on TV later that evening telling you it wasn't the big one."

Distant Threats

Few Charleston residents raised alarm when false alerts for an impending tsunami appeared on mobile devices in early February. For the East Coast, tsunamis constitute what experts call a low-probability, high-risk natural hazard, with researchers at the U.S. Geological Survey writing that "Densely populated areas, extensive industrial and port facilities, and the presence of 10 nuclear power plants along the coast, make this region highly vulnerable to flooding by tsunamis and therefore even low-probability events need to be evaluated."

While February's warning proved to be a false alarm, minor tsunamis have been recorded in Charleston Harbor, according to Jaume, although they've only reached about six inches high. In terms of potential sources for significant tsunamis reaching the East Coast, a 2014 report by researchers with the U.S. Geological Survey points to powerful quakes in Portugal's Gulf of Cadiz.

The Gulf of Cadiz sits south of Lisbon, a city that was almost completely destroyed by an 8.5-9 magnitude earthquake in 1755. Fans of Voltaire may remember the 1755 quake's inclusion in Candide and its role in showing that this may not be the "best of all possible worlds."

According to Jaume, the Lisbon quake created tsunamis that reached Canada and the Caribbean, but managed to miss everything in between.

"There are records of substantial tsunamis north of the U.S. East Coast and south of the U.S. East Coast, but as far as we can tell — and this is kind of odd — there aren't any on the U.S. East Coast," he explains. "The people who have studied that suspect that since there are islands in the Atlantic, not as many as [there are in] the Pacific, if you put the source of the tsunami in the right place, most of the waves are blocked by something and don't make it to the East Coast, but they can make it to other places. It may be fortunate positioning, which means that if you had an earthquake in a different place, you'd have a different result."

Another possible source for a tsunami in Charleston lies in the Puerto Rico Trench, as Caribbean quakes have led to some higher waves reaching local harbors. In worst-case projections following a 8.3-magnitude quake in the Puerto Rico Trench, researchers with the U.S. Geological Survey write that tsunamis erupting from that area would run north, mainly affecting the coasts of Bermuda and Nova Scotia. These same researchers do suggest that a submarine formation known as the Blake Outer Ridge may serve to direct waves toward the South Carolina coast, with swells of less than 2 meters.

Hope for the Best

Of course, these are all worst-case scenarios. Anyone who has spent a significant amount of time in Charleston tends to focus their worry on the next hurricane that will inevitably develop or the continuous flooding that encroaches upon roadways. But therein lies the true threat of these rarely occurring natural disasters.

"The past few years, everybody has been focused on all flooding, all the time. You can only focus your attention on so many things at a time. What usually gets people's attention are things that happen on a regular basis. Those become the high-probability events," says Jaume. "Obviously, high-probability and high-impact events are going to get your attention, which means sometimes the things that may have an equal or greater impact — because they are less likely to happen and if you're having too many of these other things on a regular basis — they kind of drop out of your consciousness. It's just human nature to remember the last bad thing that happened to you."

But for Jaume and Levine and anyone else with their focus on the inevitability of the next big earthquake, it's best to get your plans in place now. The Charleston area continues to grow at an alarming rate, and when the next big disaster strikes there may not be time to press pause and brainstorm a new strategy. Any major disaster requires an immediate focus on assessing damages and needs and employing the plans in place to provide emergency services. It's about triage. It's about making sure the worst problems are taken care of first and then moving forward. The difference with a major earthquake is that there may be no time to take a breath. Unlike an approaching hurricane, to which Charlestonians are well accustomed, there is no cone of uncertainty or three-day warning.

"Usually when I'm talking at an emergency management conference in South Carolina, that's the first thing I start with. You're used to knowing ahead of time that the big one's coming. This big one's going to show up at 4 o' clock in the morning when you're home, or at midnight when you're hanging out at a bar, maybe when you're having dinner with your family," says Jaume. "It's going to show up when it shows up. You'll get no warning, and you and your team are going to start your response from wherever you happen to be. There's no 'Oh, it's on its way. Let's get out the playbook and review it.' Nope. One day you're not expecting it, and then it happens."



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