It’s time for our annual ShakeOut.! No, I’m not talking about some retro-themed dance contest, I’m talking about the Great Southeast ShakeOut of 2017, which is sponsored by the Federal Emergency Management Agency (FEMA) to promote earthquake awareness in seismically-active areas–like Charleston. With this broadcast, the Charleston County Public Library is joining millions of other people around the world who are taking a moment to reflect on the potential danger that lurks in the earth just below our feet.
If you’ve just recently moved to the South Carolina lowcountry, I hope you’re not hearing this for the first time. Just as seems like hurricane season is winding down, I know it must sound rather cruel to hear that there’s another potential natural disaster looming on the horizon. Nevertheless, the fact remains that Charleston and Berkeley Counties are home to several known earthquake faults, with a history of recorded activity since 1698. In late February of that year, the inhabitants of Charleston experienced a mighty shock, but of course there were no scientific instruments to record its strength. Another mild earthquake startled lowcountry residents in April of 1799, but there were few reports of any discernable damages. In the winter of 1811–1812, South Carolinians were rattled out of bed on several occasions by a series of quakes centered around the New Madid fault, 600 miles away on the banks of the Mississippi River. We didn’t experience any real damage here, but the tremors of December 1811 and January 1812 were sufficiently potent to make folks in the lowcountry wring their hands anxiously and avoid tall buildings for several months.
“The big one” came late in the evening of August 31st 1886, when the Charleston area experienced a terrible earthquake that damaged approximately 90% of the buildings in our community. In 1886 there were no instruments to measure the strength of the quake, but, using physical data collected in its immediate aftermath, modern geologists estimate that the Great Charleston Earthquake of 1886 shook the ground with a moment magnitude between 6.9 and 7.3. The shock waves were felt as far away as Cuba, Detroit, Bermuda, and St. Louis.
But it wasn’t just one terrible shock. A few mild tremors were recorded in the days leading up to the 31st of August, and on that fateful day there were five separate shocks. Throughout the month of September 1886 there were about a dozen aftershocks of varying strength, ranging from what contemporary geologists termed “slight” to “severe.”
Similarly, the injuries caused by the earthquake weren’t confined to just one day. On the evening of August 31st and the morning of September 1st, more than two hundred people sustained serious injuries. According to the death records kept by the City of Charleston, twenty-seven people died from injuries received on that first night. In the weeks after the initial earthquake, however, thousands of people were living and sleeping outside in tents and shanties, and a further fifty-six people died from cold and exposure.
One of the most troubling aspects of the Charleston earthquake of 1886 was the fact that the local hospitals were among the buildings most heavily damaged. Roper Hospital, which was then located at the corner of Queen and Mazyck Streets, sustained serious damages, as did the City Hospital (the antebellum Work House) near the corner of Magazine and Mazyck Streets. Next door to the City Hospital on Magazine Street, part of the ten-foot-high wall around the Charleston County jail collapsed, allowing at least twenty-eight inmates to escape. All of these buildings had been built on the very edge of high land, adjacent to the tidal mud flats of the Ashley River, and surrounded by man-made fill. In the aftermath of the 1886 earthquake, both of the hospital buildings had to be demolished. According to geologists, the shock waves or vibrations caused by the earthquake caused the soil beneath these buildings to undergo what is called liquefaction; that is, the seemingly-solid soil was shaken to the point that it began to flow like a liquid. That’s a pretty scary thought, but consider this: Charleston’s present medical complex is located at the northwest end of Calhoun Street, an area that was once a large tidal mud flat in ages past. When the next big quake hits the Charleston area, the buildings we need most might be among the hardest hit.
We can’t stop Mother Nature from shaking the ground from time to time, but we can prepare for the unexpected. Governor Henry McMaster has proclaimed this to be Earthquake Awareness Week, and the South Carolina Emergency Management Division is encouraging everyone to take notice. I strongly encourage everyone to visit their website to download your own copy of the South Carolina Earthquake Guide.
Speaking of websites, the geology faculty at the College of Charleston also maintain a great website called “South Carolina Earthquake Education and Preparedness”. There you’ll find lots of useful information about the science behind earthquakes in general, which is important for understanding why the lowcountry is at risk.
But where do you turn when you think you’ve just felt an earthquake? Social media might be abuzz with anecdotal reports, but if you want the facts, check out the website of the South Carolina Geological Survey. They maintain a running list of “recent earthquakes” that includes detailed information about every minor tremor detected in our area. You can even sign up to receive a text or email directly from the U.S. Geological Survey whenever an earthquake occurs near you. I’m recording this in mid-October 2017, and there have already been more than a dozen recorded tremors in the Charleston metro region this calendar year.
The mission of the annual ShakeOut is not simply to remind folks about the tragedy of past earthquakes, but to encourage everyone to prepare for future emergencies. If the Charleston area experiences another strong earthquake, there will probably be some serious disruptions to our normal routines. We may not be able to drive to the grocery store or the hospital, for example, and those facilities might not even be open for business. Here in the lowcountry we’re accustomed to stocking up in preparation for hurricane season each year, but one never knows when an earthquake might strike. During this earthquake preparedness week, I encourage everyone to think keeping on hand a first aid kit, a supply of bottled water, and small reserve of non-perishable foods. And don’t forget about the same for your pets, too.
One of the principal goals of this annual ShakeOut is to spread the word about how to react when you feel a quake under your feet. If you’re inside a building, should you run for the nearest exit, or should you stay where you are? The answer to this important question is one simple phrase that everyone needs to memorize: Drop, Cover, Hold On. That is, stay put and get low, cover your body, or at least your head, under something solid, like a desk or a table, and hold on until the shaking stops. Do not attempt to run out of your home or office or grocery store or wherever you are. Just remember the simple phrase: Drop, Cover, Hold On. Repeat it with me now: Drop, Cover, Hold On. When the shaking stops, find a safe path to the exit and then get outside, away from tall structures. Don’t forget about the risk of aftershocks. Be vigilant, and be safe. And go to ShakeOut.org for posters and other graphics that you can use to spread the word about the plan to Drop, Cover, and Hold On.
Earthquakes are an important part of Charleston history, and your Charleston County Public Library has a number of earthquake-related books on the shelves. If you’d like to learn more about the effects of the earthquake of 1886 on Charleston’s built environment, for example, take a look at Robert Stockton’s 1986 book, The Great Shock. If you’re more interested in the social impact of the big quake of 1886, check out a book published in 2011 by Susan Millar Williams and Stephen Hoffius, titled Upheaval in Charleston: Earthquake and Murder on the Eve of Jim Crow.
Earthquakes aren’t just history, they’re also an important part of Charleston’s future, so I hope you’ll pardon this interruption in our normal routine. I’m a firm believer in the idea that the past is relevant to the present, and today’s topic is a clear example of that fact. I want your journey into the future to be a safe one, so please remember to Drop, Cover, and Hold On whenever you feel the earth move below your feet.