New Madrid Museum
The afternoon of our third day will be spent in New Madrid, Missouri, the epicenter of the famous New Madrid fault earthquakes of the early 1800's. We will drive from our morning tour at Reelfoot Lake to the New Madrid Museum and Mississippi River Observation Deck, located on Main Street in downtown New Madrid. We will have lunch along the way. The drive itself will take about one hour.
Classroom
Upon our arrival at the New Madrid Museum, we will view two 15 minute videos which will summarize the historical and geological significance of the area. We will then take about an hour to tour the museum and gift shop. The museum features exhibits about the earthquakes as well as items of historical and cultural significance to the area.
New Madrid Map
Finally, we will take a walk along the Mississippi River Observation Deck. This deck is located about half way around an oxbow meander in the Mississippi River. From the observation deck, its is possible to see from Missouri into Kentucky and Tennessee. Observers can also visualize the bend in the river and the possibility for the formation of an oxbow lake in the future.
Fault Finders Guide
After touring the museum itself, we will drive back to Memphis along US Highway 55. We will make several stops along the drive observing evidence still visible of the historical earthquakes. As a guide to our fault finding adventure, we will use a book entitled The New Madrid Fault Finders Guide. This book was written by two recognized authorities of the New Madrid Fault, Dr. Ray Knox, Geomorphologist and Dr. David Stewart, Seismologist. The book can be purchased at most online bookstores for approximately $17.00. In addition to explaining the science of earthquakes and summarizing the history of the quakes of the 1800's, the book actually is a road map to fascinating features that you can visit and observe throughout your travels in and around the Mississippi Valley. Using mile markers and road signs along the way, the authors point out specific features to see along the highway. We will use the guide on our route back to Memphis, which is US Highway 55.
Sand Blow
While there are many features to see along the way, some of the most impressive sites are the sand blows in the farming fields right off the highway. The best time of year to see these features is in the winter or spring before the crops have begun to grow. Pictured here is an aerial photograph of a sand blow in a field on our trip.
Liquifaction Diagram
Sand blows are caused when large earthquakes hit a geologic area that has abundant underground sand layers and ground water. As earthquake waves travel through the ground, they come in contact with the sand and the water. These waves force the liquefied sand out of the ground where it erupts onto the surface. Basically, as water pressure increases, it forces the sand grains apart until the sand starts to behave like a liquid, and a slurry of sand and water is forced to the surface. This phenomenon is called liquefaction. Sand blows can be seen in abundance in the New Madrid Fault Zone.
Scientists can use sand blows to help determine the period of time that the earthquake took place. This field of science is called paleoseismology. By studying the materials buried in the sand blows, like Native American artifacts for example, paleoseismologists can determine that the earthquake must have happened after that time period, therefore narrowing down the date in which the earthquake occurred.
Scientists can use sand blows to help determine the period of time that the earthquake took place. This field of science is called paleoseismology. By studying the materials buried in the sand blows, like Native American artifacts for example, paleoseismologists can determine that the earthquake must have happened after that time period, therefore narrowing down the date in which the earthquake occurred.