Monday, January 27, 2014

Microquakes & the New Madrid Seismic Zone

FIRST: Let me assure you that icequakes and earthquakes are completely different. Icequakes don't typically measure on a Richter Scale and  faults along the New Madrid Seismic Zone are not moving because of them. Icequakes are very rare and while they may have also occurred within a relatively short period of time to one another, they are unrelated.

Microquakes (3.0 magnitude or less) occur frequently along the New Madrid Seismic Zone, even dozens per year. You may not realize it because they are rarely felt or noticed because typically the event happens at a deeper depth. The microquake that rumbled parts of the area on Sunday only registered 2.6 on the Richter scale but was very shallow, making it possible to feel or hear.
About 5 years ago, I made the trip to Memphis to visit the USGS Earthquake Center and take our viewers greatest concerns and questions to the experts. I learned about how the New Madrid Fault behaved and about the historical releases of energy it produced. Here is the Associated Press award winning 3-part series that took a closer look at our past, future and preparedness concerning the New Madrid Seismic Zone:


Below is a blog I posted years ago after the very large magnitude earthquakes in Chile and Haiti made people here in the Local 6 area nervous that it could impact the New Madrid Fault:

The Center for Earthquake Research and Information describes it as this: "The New Madrid fault system, or the New Madrid seismic zone, is a series of faults beneath the continental crust in a weak spot known as the Reelfoot Rift. It cannot be seen on the surface. The fault system extends 150 miles southward from Cairo, Illinois through New Madrid and Caruthersville, Missouri, down through Blytheville, Arkansas to Marked Tree, Arkansas. It dips into Kentucky near Fulton and into Tennessee near Reelfoot Lake, and extends southeast to Dyersburg, Tennessee. It crosses five state lines, and crosses the Mississippi River in at least three places."
The last major earthquakes to rumble the New Madrid zone were in 1811-1812, 1843, and 1895. Since then thousands of smaller earthquakes, 2.0 or less, have kept the fault active. These smaller earthquakes are not enough from keeping a bigger one from happening and scientists believe that a magnitude 6.0 or greater is possible within our children's lifetime.
Earthquakes of great magnitude are nearly impossible to predict. As a resident living in this "danger zone", I can only urge everyone living here with me to BE PREPARED. Unlike an ice storm or severe weather event, we would have NO warning to prepare for a natural disaster like this one. Like a smoke detector or weather radio, an emergency preparedness kit is ESSENTIAL to have and WILL be needed in the event a large magnitude earthquake centered anywhere on the New Madrid fault zone.
Because the New Madrid fault lies beneath a continental plate, it will "radiate" for hundreds of miles and cause damage much more widespread/severe than the same size earthquake in California. Memphis and St. Louis would suffer moderate to major structural damage. With our local towns right in the middle...think of what your impact would be.

Here is my motivation for keeping emergency supplies and survival necessities. Imagine you live in a rural area in Graves County. Surrounding your area are several small, old bridges crossing the tributaries of the Clarks River. Those bridges would collapse. One would be trapped in my community for several days, if not weeks. If even one of those bridges held up, I still have to cross overpasses and major bridges over the Cumberland, Tennessee, Ohio, or Mississippi Rivers to make your way out of the region...not to mention the area roads that will be susceptible to buckling and breaking along the way. My thoughts may seem a little doom and gloom for some of you but think about it!! All very plausible if the New Madrid fault were to sustain a large magnitude earthquake.
While I try to remain positive and not think of the worst, I want to be prepared in the event my family and neighbors need help to live several days without outside help. This is a message that the Red Cross and FEMA have been trying to communicate for years and years. While those agencies would be the first to help and respond to such a disaster, they too would take a serious hit. Their families and offices would also be impacted. We would need to rely on outside help and that help may take days to reach our homes.
I am not saying you need to go out and spend several hundred dollars today to be fully prepared. What am I asking? I am hoping that each of you who read this will gather supplies with each trip to the grocery store, hardware store, or online. Preparing for this sort of disaster will also get you ready for anything!...Ice storms, severe weather, snow storms, long-term power outages.

For more help gathering supplies or making a preparedness kit, use the following links:
National Weather Service Emergency Preparedness Kit Information
FEMA Emergency Preparedness Checklist Information
Red Cross Emergency Plan Information

Make this a family affair. Children are great at helping make plans and taking on certain assigned tasks. Let them help you and it may cut down on any stress inflicted on them during disaster. Even if you only perform this once, run a practice drill like your children do at school. It is already familiar to them and will also make for less chaos when real action needs to be taken.
Thank you to all who read and respond to this by becoming more prepared. I welcome your thoughts and opinions or even questions concerning this post. Aside from being a Meteorologist, I am also a mother, daughter, neighbor, and member of this community. I encourage everyone (including my family and neighbors) to be prepared so that we can more easily help ourselves and each other if a natural disaster strikes our region.

The following story was aired on Local 6 on Monday by reporter Jason Hibbs after the weekend microquake stirred up more questions among our viewers:

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