Will you help me look up some information on the earthquake that hit OK City (and us) on Friday and Saturday?

“Preliminary data published by the USGS show that the largest of the series of the tremors, which occurred 21 miles from the town of Shawnee, had a magnitude of 5.6. It had been preceded by a series of minor tremors, with dozens of smaller events recorded in the area: all occurred at a shallow depth, around 5km. :Decoded Science

“Earthquakes produce two types of seismic waves through the earth. P waves move the eatrh’s surface mainly up and down, and S waves move it mainly side to side. The P waves travel faster so they arrive first.
As the P waves arrive at your location, they cause the ground surface around you, and your floor, to vibrate up and down, just like a loudspeaker cone. The movement is too tiny to be seen, but just large enough to cause a low frequency sound. These sounds are often described as a boom or rumble. ” Leonard Geophysical Observatory

@marinelife I know all of that general information. I’m trying to determine the specifics of the Oklahoma quake. I wouldn’t know a P wave from an S wave or a thrust fault from a slip fault if they bit me in the butt! Or…do all earthquakes produce an S AND a P wave, with the P waves arriving first and the S wave later?

I think it was a thrust fault…where one section rode up over another.

From the Leonard Geophysical Observatory:
On November 5, 2011 at 2:12 AM CDT (07:12:45.4 UTC) an magnitude 4.7 earthquake occurred in Lincoln County, Oklahoma. This turned out to be a foreshock to a much larger earthquake. The mainshock occurred at 10:53 PM CDT (11–6 03:53:10 UTC). The earthquakes occurred about 6 miles northwest of Prague and 5.2 miles southeast of Sparks. These earthquakes occurred very close to where a magnitude 4.3 earthquake occurred on February 27, 2010. From the location of the earthquake and the focal mechanism it is most likely that this earthquake occurred on the Wilzetta fault also known as the Seminole uplift. We are currently working to locate the numerous aftershocks will continue to update information as we can.

@cazzie~ thanks for providing the name of the fault. That will help me to find out what kind of incident occurred which is what I’m really after.

And why do they call them “aftershocks” when they’re just another earthquake, albeit from the same place? To me, an after shock is a delayed reaction to the main event, not a whole separate event. Like, the S-waves would be an aftershock. But a whole other earthquake 24 hours later is another earth quake.

In this instance, they called it a ‘foreshock’. I think they call it the ‘earthquake’ when the earth actually makes its move. Other feelings of the earth moving is the fault ‘settling’ and they are only small movements along the fault that are the result of the one large, main move.

That was how it was explained to me in New Zealand. Earthquakes were common there, and new for me, so I was pretty freaked out when my first one hit and I was home alone.

Well, it moved twice…Hm. I wonder how people who were making love felt when it hit! LOL!!

@Dutchess_III Yes, all earthquakes produce both a P and an S wave ith the P waves first to be felt.

Also, the first post was to answer your question about aftershocks. The first quake was a foreshock with the larger quake coming afterward.