Safety office offers steps to take during, after Oklahoma earthquakes Published May 16, 2014 By Steve Serrette 72nd Air Base Wing Safety Office TINKER AIR FORCE BASE, Okla. -- What is an earthquake? An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. At the Earth's surface, earthquakes manifest themselves by shaking and sometimes violent movement accompanied by displacement of the ground. It is a natural phenomenon that results from underground movement along a fault plane. You may think because we live in Oklahoma that tornadoes are the most violent natural phenomena we have to deal with and that we are somewhat immune from earthquakes. As we've learned in the past couple of years, that is not so. Oklahoma has many swarms of earthquakes that go unnoticed every year because they are so small, said Kenneth Luza, an engineering geologist at the Oklahoma Geological Survey in Norman. "The average magnitude for an earthquake in Oklahoma is around 2.4, which is a very small earthquake," Mr. Luza said. These earthquakes are not uncommon and are not a cause for alarm, he said. Usually Oklahoma earthquakes are more annoying than threatening and these tiny tremors have been shaking portions of central Oklahoma with increasing frequency -- rattling homes, knocking things over, interrupting sleep patterns and in general putting peoples' nerves on edge. While the root cause of the Oklahoma earthquakes is debatable (anything from fracking to underground plate movement), a number of residents have taken to adding earthquake insurance to their insurance policies, which still does not stop the phenomena. The largest earthquake in Oklahoma's history occurred in April 1952. It reached a magnitude of 5.5 and was felt from Des Moines, Iowa, to Austin, Texas. This earthquake caused moderate damage in El Reno, Oklahoma City and Ponca City, including toppled chimneys and smokestacks, cracked and loosened bricks on buildings and broken windows and dishes. One crack in the state capitol at Oklahoma City was 15 meters long. Slight damage was reported from many other towns in Oklahoma and from some towns in Kansas and Texas. The earthquake was caused by slippage along the Nemaha fault. The Nemaha zone is about 400 miles long, extending south-southwest from the Nemaha Mountain Structure in southeastern Nebraska and northeastern Kansas, across Kansas and northern Oklahoma, then south into central Oklahoma, where it splays out and terminates against the Oklahoma megashear in the southern part of the state. Say what again? In other words, the Nemaha fault line runs right underneath Oklahoma City. Yep, the Nemaha fault runs right through Oklahoma City, under the Interstate 35 and I-40 interchange, slips by the News 9 studios at Kelley and Wilshire and underneath Dr. Freddie Cudjoe's home. "Oh lord, this is something!" said Dr. Cudjoe when she learned her home was on the fault line. Dr. Cudjoe has lived in this house since 1963, but she says she does feel a little jolt now and then. "Two or three a year," she said. One of the greatest threats during an earthquake is falling debris. Earthquakes are unpredictable and strike without warning. Therefore, it is important to know the appropriate steps to take when one occurs, and to be so thoroughly familiar with these steps, that you can react quickly and safely. If you are in a commercial or residential building, remember the following procedures. Normal steps to take during an earthquake: · Remain inside the building. · Seek immediate shelter under a heavy desk or table -- or brace yourself inside a door frame or against an inside wall. · Stay clear of windows -- at least 15 feet away. · Stay where you are. But, if shaking causes the desk or table to move, be sure to move with it. · Resist the urge to panic. Organize your thoughts. Think as clearly as possible, and anticipate the sights and sounds that may accompany an earthquake. · Don't be surprised if the electricity goes out, fire or elevator alarms begin ringing, or the sprinkler system is activated. · Expect to hear noise from broken glass, creaking walls and falling objects. Steps to take immediately in an earthquake: · Remain in the same "safe" location for several minutes after the earthquake, in case of aftershocks. · Do not attempt to evacuate or leave your immediate area unless absolutely necessary or when instructed to do so by a proper authority. · Check for injuries and administer necessary first aid. Recognize and assist co-workers who are suffering from shock or emotional distress. · Implement your survival plan. Establish a temporary shelter (shelter-in-place) if rescue teams are expected to be delayed. · Use a stairway when instructed to exit building. Recent developments A rare earthquake warning was issued for Oklahoma on May 5. Mile for mile, there are almost as many earthquakes rattling Oklahoma as California this year. This major increase in seismic shaking led to the warning from the U.S. Geological Survey and the Oklahoma Geological Survey. In a joint statement, the agencies said the risk of a damaging earthquake -- one larger than magnitude 5.0 -- has significantly increased in central Oklahoma. Geologists don't know when or where the state's next big earthquake will strike, nor will they put a number on the increased risk. "We haven't seen this before in Oklahoma, so we had some concerns about putting a specific number on the chances of it," Robert Williams, a research geophysicist with the USGS Earthquake Hazards Program in Golden, Colorado, told Live Science. "But we know from other cases around the world that if you have an increasing number of small earthquakes, the chances of a larger one will go up." (Some information taken from livescience.com.)