EDITOR'S NOTE: Earthquakes are unpredictable, but to get a sense of the threat the Lowcountry faces, reporter Robert Behre interviewed Dr. Norman Levine, a geology professor at the College of Charleston and acting director of the Lowcountry Hazard Center.
P&C: What are our chances of being hit with another Magnitude 7 earthquake like the one that struck in 1886?
Levine: "The 1886 earthquake was an extremely large event. When we think about earthquakes, we think about them being on a cycle. ... Others have calculated that this recurrent cycle (for a major earthquake) is on the order of approximately 500 years, give or take. ... The lowest estimate for reoccurrence of a large earthquake in the area has been set at about 150 to 250 years. That doesn't necessarily mean a 7.0. That could be something in the 6 range. We don't have enough historic information to give us an exact figure."
P&C: What about smaller earthquakes?
Levine: "Smaller earthquakes we have a better fix on, and that's why right now, we're planning on something in the 5 range."
P&C: What's the likelihood of an earthquake with a Magnitude 5?
Levine: "With earthquakes, we can't predict whether it's going to be in the next year, five years or 25 years... . All we know is that a 5.0 occurs much more frequently than a 7.0, just as we know a 3.0 occurs much more frequently than a 5.0."
P&C: Do the recent run of disastrous earthquakes in Haiti, Chile, New Zealand and Japan portend doom for us?
Levine: "No. They are not related to our system and do not portend doom. We look at them as completely unconnected, not related."
P&C: How vulnerable are we to a significant earthquake today compared to 1886, when the last one struck?
Levine: "I actually believe we're probably more vulnerable to damage from a significant earthquake. Our exposure is much larger because we're a much larger place."
P&C: What else might make us more vulnerable today?
Levine: "Because our population has increased, we have built onto more marginal land, and by marginal land, we're talking about land that had been marshes or had been filled areas that we've turned into land. Those areas are much more vulnerable, and there are larger populations and more infrastructure on that land now."
P&C: What is the most important thing we can do as a community to increase our resiliency or preparedness for earthquakes?
Levine: "One is being aware that we are in an earthquake area. That allows us to be prepared. With an earthquake, there is no pre-warning, so that hurricane kit we make once a year you should keep all year-round as your earthquake kit."
P&C: Would a Charleston earthquake pose a tsunami problem for us?
Levine: "Tsunamis are not expected from a Charleston earthquake, but for Charleston, because we are a coastal city, we are susceptible to tsunamis from either the Canary Islands or potentially the Caribbean plate."