Lakeview Oregon quake swarm.

originally posted by: canucks555
M4.5 - 63km ESE of Lakeview, Oregon

earthquake.usgs.gov...

people felt that one!

I saw it come in live on my rig, looked at the raw data, and estimated 4.7 to 5.1 after comparing it to some others there. And guess what? USGS just changed the location and upped the mag to 4.7.

earthquake.usgs.gov...

Something is going down over there...

EDIT: they just changed the location AGAIN, and upped the mag further to 4.8. Nice and neat into the middle of my estimate range.


ROFL, they did it again! Now a 4.9!

a reply to: TrueAmerican

They change it up often. It's crazy how they just can't get a firm handle on where these things are going off exactly.

a reply to: TrueAmerican
Hey TA, I just found a bit more info concerning the possibility of volcanics in the area.

This info is from the seismo lab at the University of Nevada, Reno.
www.seismo.unr.edu...
I can't link it directly because it is from a pop-up window, but if you click on the photo on the main page, the story comes up.

The Nevada Seismological Lab will be collecting more data from the swarm with the installation of additional real-time seismographs completed this week. The stations are closer to the activity and will improve locating the seismic events, Smith said.

So, they have additional monitoring equipment in place.

Some residents have asked if the tremblers are related to an extinct volcano in the Sheldon Refuge.

"We know the Sheldon seismicity swarm is in the shallow crust and seems to have character that is consistent with the regional faults," Bill Hammond, with the University's Nevada Geodetic Laboratory, said.

Using GPS satellites and ground stations, the University's Geodetic Lab measures the shape of the Earth and monitors tectonic and volcanic activity. They track any uplift or subsidence in the range of millimeters all across the globe. The University maintains the world's largest GPS data processing center, able to process information from about 13,000 stations around the world continuously, 24/7.

"We have looked at data from stations that are about 50 kilometers from the swarm and see no anomaly," Hammond said. "We would not expect to, given the size of the swarm's earthquakes and distance to those stations, so we have recently installed more stations near the epicenters and have plans for more."

In recent years, they have measured background plate deformation in the broader northern Basin and Range, including the Sheldon area.

"We see tectonic stretching and shearing of the crust in the vicinity of the swarm at a rate of about one millimeter a year over the 100 kilometers centered on the swarm," Hammond said. "This stretching drives earthquake occurrence in the crust which can be expressed as vigorous swarms we sometimes get in Nevada. However, conclusively ruling out a volcanic source will require the additional seismic and geodetic measurements closer to the events."

Following any sequence of earthquakes similar to what is occurring in northwest Nevada, there is a small increase in the probability of a larger event. Whether a larger event will occur in the northwest Nevada swarm cannot be predicted or forecast. However, large earthquakes can happen anywhere in Nevada, and officials encourage citizens to take steps to prepare for the potential for strong ground shaking.

"Right now, it's not making much impact on the nearest communities, but if this gets into the magnitude 5 range a couple of communities will start to see an impact, and if it reaches magnitude 6.0, which is always a possibility in Nevada, we could see some impacts on people and damage to structures," Kent said. "If this intensifies, the shaking will become more prominent in the communities nearest the epicenter. As with a couple of other swarms we've seen in recent years, this gives the community some warning and time to prepare in case a damaging quake happens. It's a good reminder for all of us that we live in earthquake country."

They aren't able to rule out a volcanic source just yet. Interesting swarm.
[and a belated "Happy Thanksgiving" to you ]

a reply to: Olivine

Hiya Oli,
Thanks and same Happy Holidays to you too!

Yes, this is a curious swarm in that it is lasting so long, for it to be tectonic. Not that it is all that uncommon, but it is curious that they are indeed installing GPS and more seismometers, just to be sure. And even then they won't be totally sure- just MORE sure.

The 5km to 10km depth range is generally the range that we find magma chambers- except for much larger volcanoes. Some of the quakes here have been at that depth, but many more are even more shallow.

In pulling a 30-day activity at USGS of quakes 2.5 Mag and above, we see this here:


It is curious to me the oval, rounded shape of the affected area, possibly characteristic of volcanic activity, but not necessarily.

If this is anything like the swarm that happened near Reno, then it is probably nothing, and will die down. And even if it IS volcanic, the remote area involved will mean little if any damage if goes off all of a sudden.

a reply to: TrueAmerican i just looked at the satellite and terrain views in google earth, and indeed you can see valleys perhaps due to spreading. and i have to say, this is they way all threads should go on ats..an empirical what the heck to good info and pointers to solid info, like U nev planting more sensors and gps at the quake swam center.