As a Kansan, I never thought I would feel an earthquake, at least not while within the borders of my own state, and certainly not within the confines of my home. But, it is happening with more and more regularity these days. Friday evening, as I sat at my computer contemplating a subject for my next column, I felt the earth move.
I have felt temblors in the past, though I was never sure if I was feeling an earthquake or just a truck rumbling by on the street in front of my house.
The only other time I was sure the ground was shaking was at 4 in the morning when I just happened to be awake. The TV on the wall in the bedroom shook for a few seconds. It was certainly less than dramatic, and it was more than a year ago.
But, when I felt Friday?s quake, it was a no-brainer. I knew immediately what was going on. It was less of a vibration and more of a shake from way down deep, kind of like when I have too many burritos in a 24-hour span.
I wanted to confirm that I was right, so I waited a couple of hours and checked my smartphone. I have several weather apps on, but the only one I know of that has earthquake information is the Storm Team 12 app from KWCH. It shows what look like small targets of various colors and sizes. Each represents an earthquake.
I am constantly amazed by how many tremors happen each day in southern Kansas and northern Okla?homa. The one I experienced was a 4.0 magnitude on the Richter Scale with its epicenter 6 kilometers north-northeast of Anthony. It rumbled at 6:12 p.m. It was one of six that were showing in the region for the previous two days.
According to earthquaketrack.net, there were three more quakes in Kansas on Saturday, 10 in the previous seven days, 37 in the past month and a whopping 660 in the past year. Oklahoma has recorded 1,839 in the past 12 months.
Are all these earthquakes the result of the oil exploration method known as fracking? I have no doubt that human activity in the area is at least partially to blame for the shaking ground. Others may disagree, but there is no doubt that the phenomenon is recent. Something has changed.
Earthquakes fascinate me, probably because I did not grow up experiencing them on a regular basis. I remember my dad talking about one when I was a kid, but that was as close as I came before the seismic activity began to ramp up a few years ago.
I don?t want to feel a temblor on the scale of the recent quakes in Nepal. I doubt we will be seeing anything close here in Kansas.
When it comes to earthquakes, less is better. A magnitude 5 earthquake, for example, is actually 10 times larger than a magnitude 4, but it is 31.622 times stron?ger, according to the U.S. Geological Society website that includes a calculator to figure the relative sizes of quakes.
Take that number up to a 6 magnitude, and you are talking about an increase of 100 times in size and 1,000 times in strength. That would do some serious damage around here. Most concrete in the Hillsboro area is already cracked enough without adding that strain to the equation.
A few additional facts for budding seismologists, courtesy of the USGS website:
? Earthquakes are sudden rolling or shaking events caused by movement under the Earth?s surface.
? The ?megaquakes? of the movies are all but impossible. The largest earthquake ever recorded by seismic instruments anywhere on the planet was a magnitude 9.5 earthquake in Chile on May 22, 1960. A magnitude 12 earthquake would require a fault bigger than the earth itself. Additionally, the earth will not split during an earthquake and will not swallow anyone or anything.
? Though well known, the 1906 magnitude 7.8 San Francisco earthquake and ensuing fire killed 3,000 people and razed large sections of the city. It was the most deadly in U.S. history, but that doesn?t make it the worst the world has seen, by far.
? The deadliest earthquake in recorded history struck Shensi province in China in 1556, killing about 830,000 people. The 1976 magnitude 7.8 earthquake which struck Tangshan, China, killed somewhere between 250,000 and 800,000 people. In 2003, the magnitude 6.5 earthquake in Bam, Iran, killed more than 40,000 people.
? In 2014 there were 585 M3 and greater earthquakes in Oklahoma and about 200 in California. As of April 2015, Oklahoma (260 events) is still well ahead of Califor?nia (29 events).
? It?s absolutely impossible that California will be swept out to sea during an earthquake. Instead, southwestern California is moving horizontally northward toward Alaska as it slides past central and eastern California.
? Aftershocks cannot by definition be larger than the ?mainshock.? If a later quake is the largest, it becomes the ?mainshock,? and the others become ?foreshocks.? It is possible for two earthquakes of the same size to occur simultaneously.
? Humans cannot prevent earthquakes from happening, or stop them once they?ve started.
? Changes in animal behavior cannot be used to predict earthquakes. Even though there have been documented cases of unusual animal behavior prior to earthquakes, a reproducible connection between a specific behavior and the occurrence of an earthquake has not been made. Because of their finely tuned senses, animals can often feel the earthquake at its earliest stages before the humans around it can. This feeds the myth that the animal knew the earthquake was coming.
? Many people believe that earthquakes are more common in certain kinds of weather. In fact, no correlation with weather has been found.
? Fact: Earthquakes don?t kill people, buildings and their contents do. The greatest risk in an earthquake is the severity of the shaking it causes to manmade and natural structures and the contents within these that may fail or fall and injure or kill people. Also, the USGS recommends that people remain in buildings, lower themselves and hang on during quakes rather than flee outdoors or stand in doorways.
? Earthquakes induced by human activity have been documented in the United States, Japan and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil and the filling of large reservoirs for water supplies. Most of these earthquakes were minor. Deep mining can cause small to moderate quakes, and nuclear testing has caused small earthquakes in the immediate area surrounding the test site, but other human activities have not been shown to trigger subsequent earthquakes.