Our names are Kayla Lipscomb, Kyle Morella, and Ana Moye. We attend College of Charleston in South Carolina and live in the McAlister Residence Hall located on St. Phillips Street. In our Environmental Geology Lab, we have recently learned about the devastating earthquake that occurred in Charleston, SC in 1886. We were amazed by the information and began to wonder "hmmm...if an earthquake occurred in Charleston again, would we be safe on our campus?" This question led us to dig in and begin our research on the 1886 earthquake and the underlying topography of the Charleston peninsula.
We would like to invite you on our journey to answer questions like this, so sit back, relax, and enjoy the ride!
-The Earthquake Public Service Announcement Staff of South Carolina
Ancient barrier island: finer sandy material - much more compact and consolidated than modern deposits, firmer than modern deposits yet still fairly soft
Artificial Fill: muddy with water present - other materials are in the mud like brick and concrete remnants
Cooper marl: very compact sediments
Earthquake: occur on faults along plate boundaries and are caused by the release of energy built up in the earth where rocks are sliding past one another
Fault: a fracture along which the blocks of crust on either side have moved relative to one another parallel to the fracture and cause earthquakes to happen
Liquefaction: occurs when sediments are not compact and filled with water
Modern barrier island: sandy unconsolidated material - just like beach sand - coarser grain sand
If you didn't already know, Charleston, SC had an earthquake in 1886! However, this wasn't just a normal earthquake, Charleston had the largest earthquake to EVER occur in Southeastern United States! The earthquake was estimated to have been up to 7.3 on the Richter scale and destroyed cities miles and miles away!
Background Information
Damage seen by the Great Earthquake of 1886 (taken on the south side of Broad Street)
Tuesday, August 31st, 1886, around 9:51 PM, sleeping Charlestonians were awaken by sudden and violent shaking. In minutes, this shaking led to catastrophic damage! Although the epicenter of the earthquake was in Summerville, SC (almost 25, miles away), Charleston saw the most damage.Numerous homes/buildings were destroyed and there were deaths of more than 100 people! The earthquake was even felt and damaged buildings as far East as Bermuda. The total cost of damage in Charleston alone $5 million ($12 million in today's money). The money was spent to do repairs such as install earthquake bolts or fix damaged waterways.
Earthquake Intensities by County
How Do We Know That Charleston is in Danger of Another Earthquake?
Charleston is located on one of the most an active fault systems in the Eastern United States (known as the Middleton Place Summerville Seismic Zone). Charleston is likely to have another earthquake in the future. According to geologists, there is an 40%-60% chances of a 6+ magnitude (on Richter scale) earthquake somewhere in the Eastern United States in the next 30 years.
What If It Happened Today? (Hazards and Risks)
If Charleston had an earthquake like the one in 1886, the damage would be disastrous! This is because Charleston is a historic city which includes many old buildings that would crumble, and since there are many more people living in Charleston now than in 1886, there would be a vast number of fatalities (the falling debris from old buildings would kill many people). Fires will also occur and burn down buildings and add even more damage from the earthquake. Furthermore, Charleston is built on artificial fill which consists of mud, brick, and unconsolidated sandy material. This material would not be stable enough to withstand the tremendous forces of seismic waves during an earthquake making it prone to liquefaction causing buildings to sink and topple.
Here is a video about the Great Earthquake of 1886:
Here is an article from a witness describing their first-hand experience:
Topographic Hazard Map of Charleston with Shaded Danger Zones
Key
C of C: College of Charleston
B: Important bridges in high damage zone
F: Important fire stations in high damage zone
H: Important hospitals in high damage zone
I: Coast Guard
MB: Important municipal buildings in high damage zone
P: Important police stations in high damage zone
S: Important streets in high damage zone
Red: Zones that would experience HIGH damage
Foundation: Consists of artificial fill (see Words You Should Know!) which is extremely unstable during an earthquake
Result: Catastrophic destruction. Buildings or anything resting on this type of foundation would topple and sink into the ground. Liquefaction (see Words You Should Know!), flooding, high casualty count, and water surges may also occur.
Yellow: Zones that would experience INTERMEDIATE damage
Foundation: Consists of each deposits such as modern barrier island (see Words You Should Know!) which is moderately stable during an earthquake
Result: Depending on the type of material a building is made out of, there should be moderate destruction and a normal casualty count.
Green: Zones that would experience LOW damage
Foundation: Consists of Wando formation such as ancient barrier island and cooper marl (see Words You Should Know!) which is very stable during an earthquake.
Result: Depending on the type of material a building is made out of, there should be little destruction and a low casualty count.
Aerial photograph of downtown Charleston overlain on the present day geologic map. Note that much of the present day city is built on formations labeled as “Artificial Fill” “Tidal Marsh” or “Estuarine Deposits”. These materials are extremely unstable under conditions of severe shaking present during a large earthquake.
Topographic Hazard Map of Charleston with Shaded Danger Zones
Key
C of C: College of Charleston
B: Important bridges in high damage zone
F: Important fire stations in high damage zone
H: Important hospitals in high damage zone
I: Coast Guard
MB: Important municipal buildings in high damage zone
P: Important police stations in high damage zone
S: Important streets in high damage zone
Red: Zones that would experience HIGH damage
Yellow: Zones that would experience INTERMEDIATE damage
Green: Zones that would experience LOW damage
Key Infrastructures Located in High Damage Zones
Hospitals: Medical University of South Carolina
Murray Hospital
Baker Hospital
Medical University of South Carolina
Bridges: Ashley River Memorial Bridge
Cooper River Bridge
Cooper River Bridge
Coast Guard
US Coast Guard Logo
Police stations: County Jail
Charleston County Police Station
Charleston Country Police Department Logo
Streets: Calhoun Street
Lockwood Dr.
Francis Marion Hotel on Calhoun Street
Municipal buildings: U.S. Customhouse
United States Customhouse in Charleston, SC
Fire stations: Charleston County Fire Department
Charleston Country Fire Department
Why They Are Located in High Risk Hazard Zones
As you can see from the Generalized Geologic Map of the Charleston Peninsula and Surrounding Areas above, all of these important infrastructures are built on artificial land (see Words You Should Know!) and modern barrier island! This means that the ground is unstable during an earthquake and susceptible to liquefaction. Liquefaction happens when the ground becomes soft due to ground shaking and sand behaves as a liquid. As a result of liquefaction, buildings will topple and sink into the ground. Another important factor is that a lot of the buildings in Charleston are made of brick. Brick buildings sustain more damage than wood buildings because they do not allow movement causing buildings to crumble and crack rather than simply shaking.
Here is a helpful video further explaining liquefaction:
What Would Happen If These Infrastructures Were Lost
If these important infrastructures were lost, there would be no way to get emergency medical attention or help from the police department. Eventually, fires would spread throughout Charleston without a fire department to put them out and severely damage the city and even be the reason for fatalities. Furthermore, the flooded and destroyed streets/bridges would pose a problem because even first responders wouldn't be able to travel to help anyone! Essentially, Charleston would be in complete chaos!
Here are some GREAT earthquake tips provided by The Association of Environmental and Engineering Geologists!
Preparation!
Surveyyour home or workplace and secure fixturessuchaslights,ceilingtiles, cabinets, electrical wiring, gas appliances, andtop
heavyobjectsto resistmoving,comingloose,or fallingduringthe shaking.
Have on hand:
1.A
flashlight and battery-powered radioincaseyou lose power.
2.A
supplyofdrinking waterand nonperishablefoodsthat can be prepared without cooking.
3.A fireextinguisher and firstaidkit.
Develop
a familywork
planwhichaddresseswhattodoifthe
earthquake occurs whilefamilymembers
are at home,schoolor work. Discusswhere and how contact should be madeand wheretomeet.
Practiceyourplan.
Hold drills so eachmember of your
family knows what to doin an earthquake. Teach responsiblefamilymembershowtoturn
off electricity, gas,and water atmain switches and valves.
What To Do During an Earthquake?
Stay calm. This is one of the most important things to do. Thinkingthroughthe consequences ofany actionyou
take will save your life. Do not make any rash decisions, stay put and wait for help.
Stay
put.Ifyouareinside,stayinside.If youareoutdoors, staythere.Mostearthquake injuriesoccur whenentering or leaving
buildings.
Take cover. Ifindoors, or in a school follow the schools safety protocol, take cover under aheavydesk, table, bench, a supported doorway, or alongan
inside wall. Stay awayfromglass.Don't use candles, matches, or other
openflameduring orafter thetremor because of possible
gas leaks. Douseallfires.
If outdoors, move away frombuildings
and utilitywires. Onceintheopen,staythereuntil theshakingstops.Ifin
a moving car, stopasquicklyas safetypermits, but
stayinthevehicle.A carmayshakeviolentlyonits springs,butitis
a good placetostay untiltheshakingstops.
After the earthquake!
Aftertheearthquakeessentialservices maybeoutfor
a fewdays.Theuseoftelephones willprobably be impaired forsometime.
If your phoneis working,itwould bebestnot to burdenthelineswithunnecessary
calls.
Beprepared
for additionalearthquakeshocks called aftershocks.Althoughmost
of thesearesmallerthanthemainshock,somemay be largeenoughto causeadditionaldamage or toppleweakenedstructures.
Checkforinjuries . Do notattempt
tomoveseriously injured
persons unlessthey areinimmediatedanger of furtherinjury.Turn
onyourradio ortelevision to getthelatestemergencyinformationfromlocalauthorities.
Checkyourutilities . The
earthquake mayhave
broken gas,electrical, andwaterlines.Openwindowsandshut offthe maingasvalve, electrical meter box, and water supply value if damaged. Emergencywater
may be obtained fromhot
watertanks,toilettanks (notbowls),andmeltedicecubes.
IMPORTANT NUMBERS:
Charleston County Emergency Preparedness: 843-202-7400
Charleston Co. Sheriff: Call 911 for emergencies only!
Congratulations, you've made it to the end of our journey! We hope that you enjoyed learning about earthquakes as much as we did! Now you will be prepared for any earthquake that comes your way! Good luck!
Here are some helpful links to further educate you about earthquakes:
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