robertjerl Loc: Corona, California

This one has now been pegged at 7.1 by the USGS and in the same general area as the others.
So those others are now "fore-shocks" since this one was bigger. It was also a long rolling quake as opposed to a sharp jolt.

And for those who have not studied geology. The part of California west of the San Andrea fault actually rises up higher it is not falling into the Pacific.
The tectonic plate to the west of the fault is in the process of riding up over the edge of the mainland plate to the east.

And sometimes that rise and or drop difference can be huge, one quake in Japan in the 20th century caused a 16 story elevation change between the two sides of the fault.

There is one cliff in the Sierra Nevadas that is over 1000' and apparently was done in a single super quake.

The New Madrid quake in the winter of 1811-1812 rang church bells in Boston, was felt in the White House (7.5 -7.9 is the guess of the minimum power and two in that range took place on the same day), and caused people sleeping on the ground to be tossed 2-3 feet up as recorded in some diaries/journals. there were also reports of large trees that whipped back and forth so hard the trunks broke. It also dropped a range of hills said to have been up to 100' tall along the east bank of the Mississippi to subside and form Reelfoot Lake TN which even today after a lot of sediment is still 18' deep in places. So much water ran in to fill the new lake that the Mississippi ran backwards or a while.

robertjerl Loc: Corona, California

Reports now are the reason the earthquake lasted so long was it was two that overlapped.
a 5.4 and then nearby on the same fault system a 7.1
And a swarm of smaller ones though at least two at 5.0 and above.
The total for the last few days is 1400+ strong enough for the instruments to measure.

tommy2 Loc: Fort Worth, Texas

You've packed plenty of info into your post, must have been around USGS many years.
We have slight quakes here in the DFW area of Texas, felt a small "bump" just a day or so ago. Those are blamed on Fracking - what do you think?

DirtFarmer Loc: Escaped from the NYC area, back to MA

I have only felt one quake, although there have been several that occurred when and where I happened to be. Most of them were small, <3.
The one I felt was in Massachusetts.
(No, not the New Madrid quake. I'm old, but not THAT old).

Speaking of infrequent occurrences, I have seen two tornadoes. One was in Massachusetts. The other was at the Denver airport. The Denver airport is in the middle of fairly flat country, and the tornadoe was probably 25 miles away. It did not affect flight schedules.

robertjerl Loc: Corona, California

Classroom teacher, history, geography, government.

We don't know, fracking may be one of many factors, but so could a trillion butterflies all landing at once. Old mine tunnels caving in have caused tiny local "quakes".

But as to the fracking - since small quakes have been recorded in the past the oil companies would need time machines to have gone back and caused them if fracking was the only cause.

Though fracking may be a factor I think the anti-fracking people are just using it as a way to boost their own personal dislikes/ideas.

robertjerl Loc: Corona, California

According to the state gvt CA does not have tornadoes. But the weather guys do report "tornado like winds" and "water spouts". I witnessed one of those "tornado like winds", it was a tornado, a baby one, but a tornado. Just barely big enough to not just be labeled a "whirlwind" which is just a stunted little very small baby tornado that is usually very short lived.
As to "waterspouts" those are just tornadoes that went for a swim.

G Brown Loc: Sunny Bognor Regis West Sussex UK

As I understand it - pumping oil out of the grounds leaves a void - which may or may not collapse (like mines) fracking involves pumping water to wash up oil (it floats) up to the surface leaving water filling the voids..as an aquifer...less likely to collapse but MORE likely to contaminate the natural water table that we drink from.

quagmire Loc: Greenwood,South Carolina

when I was a kid a coal car jumped track five miles away and you could feel it.

LoisCroft Loc: Jonesborough, Tennessee

Very interesting. Thanks for the good information.

jerryc41 Loc: Catskill Mts of NY

This planet is killing people. Maybe it's trying to tell us something.

I've often wondered if aliens looking for another place to live would consider settling on earth, considering the weather and geology.

HamB

Earthquakes are caused by Global Warming...

sb Loc: Florida's East Coast

The USGS blames them on fracking and has published a very interesting report about it.

DirtFarmer Loc: Escaped from the NYC area, back to MA

While fracking can contribute to the occurrence of earthquakes, earthquakes have occurred long before fracking started.

DirtFarmer Loc: Escaped from the NYC area, back to MA

I would expect any planet capable of sustaining life would have its own quakes, whatever they would be called.

DirtFarmer Loc: Escaped from the NYC area, back to MA

The same thing happens when too much water is extracted from aquifers, as California is finding out. Not necessarily producing earthquakes, but subsidence. And subsidence packs the earth so it can't hold as much water as it once did.