3.3 earthquake near Huntington, WV

[mk378]

Fracking for oil and gas causes many small earthquakes. I don't know if a fault has to previously exist for this to happen. In most cases no one knows there is a fault underground until an earthquake is observed.

 

[TiGeo]

Does the type of fault ie normal vs strike slip etc change the intensity or earthquake characteristics? I've seen videos from Japan where it looks like the earthquake was completely horizontal on Movement but the 1989? Earthquake looked like it had vertical movement as well. Then add in liquefaction and hold on.

No idea. Not a seismologist. I don't recall that there would be a difference from geo 101 34 years ago . P waves. S waves.

 

[bbhero]

About 4:30 we had an earthquake. My dogs started barking like crazy so I got up off the couch figuring fed ex was delivering something then I heard a super low rumble that lasted like five seconds and then boom, it sounded like a sonic boom. I instantly thought that my gas HVAC system had just exploded. It rattled the windows a bit but no damage.
I swear I have never heard/felt so a low frequency before in my life. USGS has pinpointed it to about a mile and a half from my house.

Your description is almost just like what I experienced at my sisters house in the summer of 2008.. And it was a 3.3 has well. That was a half mile from her house. I had literally just woke up from sleep at 4 am… then literally a minute later… cloud boom and then the house shook pretty good for a few seconds. I checked my phone for weather radar… no thunderstorms within 800 miles of Roanoke Va…

My first thought was.. an earthquake nearby. I heard my brother in law and sister talking downstairs.. Ot soooked them really good. My brother in law and I drove around the neighborhood because he thought it could have been an airplane crash nearby. Which to be fair we were up on a small mountain and the airport is only 8 miles away. As we go out a number of of other p we’re up and outside waking outside. We went to the very tip of that small mountain and it was fine. At that point my brother in law said it had to have been an earthquake. And it sure was.

 

[goingplacesanddoingstuff]

Does the type of fault ie normal vs strike slip etc change the intensity or earthquake characteristics? I've seen videos from Japan where it looks like the earthquake was completely horizontal on Movement but the 1989? Earthquake looked like it had vertical movement as well. Then add in liquefaction and hold on.

Like most scientific topics, it’s more complicated than it seems. Faults have more ways of being categorized than their fault sense descriptions we learn in geology 101. The character of an earthquake has more to do with tectonic setting, fault depth, and amount of energy released (ie how much displacement occurs).

For example, a minor subsidence-related normal fault 5000 ft deep could activate in response to wastewater injection in Oklahoma and result in a 3.0 magnitude quake.

On the other hand, a relatively major earthquake could result from basin and range normal faulting at 7 km depth resulting in a 6.0 magnitude quake in Nevada. Same fault sense, very different quakes.

Really big quakes generally result from really big structures moving. Many very different geologic settings can have big stuff moving in many different ways.

Geologic settings which contain active subduction, major basin subsidence, wrench zones, crustal extension or rifting, continental collision, major volcanism, or isostatic uplift are more likely to create larger earthquakes. Each will contain different relative fault motions and different fault geometries depending on the principal stresses involved, and at varying depths depending on the particular geology.

Short answer, yes, kinda. But both the fault characteristics and the earthquake characteristics follow from the overall geologic setting.