The article ("A Watched Pot Never Rattles" by Greg Hambrick, May 7) contains glaring errors of fact and assumptions about earthquakes in the Charleston area and the hazards they present today.
1. The 1886 Death Toll. In this article, the death toll for the 1886 earthquake was misstated as "60 people." This statistic has been wrong since the fall of 1886, when the city listed 83 earthquake-specific fatalities in its official city death record. Recent research, published in my book, City of Heroes: The Great Charleston Earthquake of 1886, positively documented at least 124 deaths and over 140 serious injuries. There were more which went unrecorded.
2. Where will the next "big one" happen in S.C.? That is known to every geologist who has ever studied South Carolina earthquakes. It will likely happen along the Woodstock Fault, which runs through the center of the Middleton Place-Summerville Seismic Zone (MPSSZ), which generates 8-12 new earthquakes every year. The latest example was a small (Magnitude 2.4) earthquake beneath Hanahan on October 13. Over 2,000 new earthquakes have originated in the MPSSZ since 1886. "Where" earthquakes will strike next is an easy call for geologists: they will strike in exactly the same places as the last ones did. The reason is simple: unlike hurricanes, which have a different track each time, earthquake fault zones don't move. The next ones will come from the exact same places as the last ones.
3. When will the next "big one" strike"? We know the average time between catastrophic earthquakes in the Charleston area is between 500 to 550 years, but this tells us nothing about when the next big one will strike. Earthquakes strike when the pressure along a fault line builds up to a certain level and is then discharged in a burst of energy called an earthquake. But earthquakes do not run on a countdown clock. The next "big one" here may not happen for 1,000 years — or it may happen tomorrow afternoon. We must prepare NOW.
4. How bad will the next "big one" be here? Catastrophic almost beyond imagination — and this is not just alarmist theory. And the damage will not be limited to the Charleston-Summerville area. All of South Carolina, and about a third of North Carolina and Georgia will suffer structural damage — just as in 1886.
South Carolina is one of the four most earthquake-active states in the nation. We must pay close attention to the clear and present dangers or risk the deaths of thousands of innocent people who could have been saved.
Richard N. Côté
Director, South Carolina Earthquake Awareness Project
Greg Hambrick responds:The story mentions 60 deaths, per information from the U.S. Geological Survey. The story doesn't suggest that the next earthquake will happen anywhere else but where it happened before. As for the third and fourth complaints, well, that debate is what the story is about. Mr. Côté's opinion is that of most seismologists, but this new study claims they're overreacting.