Earthquakes!

The recent earthquakes in Oklahoma, which were felt in Oklahoma, Texas, Arkansas, Kansas, and Missouri, have many people on edge. Some people weren't aware of the possibility of earthquakes in Oklahoma, and some people weren't aware that the quakes could be so powerful. Earthquakes have been reported in Oklahoma about every year, but it's no secret that over the past couple of years the quakes have gotten stronger and more frequent. Before the past couple of years, Oklahoma saw 50 earthquakes per year, many too small to be felt, but last year that number increased to 1,047 quakes. Here's a map of some of the earthquakes that followed yesterday's 5.6.             
 
Yesterday morning there was a 4.7 earthquake in Oklahoma about 6 miles SE of Sparks, in Lincoln County. Following the earthquake there were several other earthquakes, ranging between 3.0-4.0, that were believed to be aftershocks following the 4.7. Then late last night a 5.6 quake shook not only Oklahoma, but the surrounding states too. That 5.6 quake was centered 5 NW of Prague, Oklahoma. This means the 4.7, and all the other quakes following, were not aftershocks, but foreshocks. (A foreshock is an earthquake that occurs before a larger earthquake.) Now that leaves one question, was the 5.6 the larger earthquake, or was that one a foreschock too? We don't know the answer to that, but if there was going to be a quake it would happen in the near future. Here's a list of the strongest earthquakes in modern Oklahoma history, not including the recent events.

What makes the quakes so noticeable and felt over such a wide radius is that they've been so shallow; all of the quakes over the past 48 hours have been only three miles below the earth's surface. There are fault line in and near Oklahoma. Some of these faults have produced major earthquakes including 7.0-8.0+. The biggest, and potentially most dangerous, fault line in Oklahoma is the Meers Fault Line in SW Oklahoma. It's an active fault line that runs east to west, and has produced a couple 7.0 earthquakes about 1,300 years ago.

The New Madrid Fault Line which extends into several states including Arkansas, poses a threat to Oklahoma and Texas. This fault line has produced four major earthquakes in the 1800's believed to be 8.0's. In 2008 the Federal Emergency Management Agency warned that a major earthquake near this fault line would cause widespread damage and casualties. Many questions remain about the fault line and the possibility of an earthquake in the near future, but research continues to be done on the fault line.

While a 6.5+ earthquake is not imminent in our area it is a possibility. Most houses and buildings in our region are not built to withstand an earthquake, so precautions need to be taken. In the event that you're in an earthquake take shelter under a table, cover your head and eyes from flying debris, if you're outside get away from buildings and power lines. Just as I'm finishing this update, a 3.7 earthquake was reported near Sparks, Oklahoma.
Here's a couple great sites to check out:
http://www.usgs.gov/
http://www.ogs.ou.edu/homepage.php