Distant Earthquakes Can Trigger Deep Slow Fault Slip: USGS

Distant Earthquakes Can Trigger Deep Slow Fault Slip

USGS

Update May 10, 2011 -- Researchers David Shelly and David Hill from the U.S. Geological Survey, and Zhigang Peng and Chastity Aiken from Georgia Institute of Technology examined the locations and timing of tremor activity following large distant earthquakes.

Researchers examining the San Andreas Fault in central California have found evidence that distant earthquakes can trigger episodes of accelerated (but still very slow) slip motion, deep on the fault.

While a sudden slip on a fault generates earthquakes capable of strong shaking, a fault can also slip slowly. Sometimes, these slow movements on a fault, known as creep events, are accompanied by a weak ground vibration known as a tectonic tremor, which can be detected on sensitive seismometers.

Using data from these seismometers, researchers from the U.S. Geological Survey and Georgia Institute of Technology examined the locations and timing of tremor activity following large distant earthquakes. In some cases, they found evidence that triggered slip and its associated tremor migrated along the length of the fault, and persisted long after the passage of seismic waves from the distant earthquake. The scientists hypothesize that distant earthquakes can act as a trigger for ongoing episodic creep events, sometimes altering their timing.

The researchers also noted that creep events in other locations can sometimes trigger earthquakes. While they caution that their study was focused on triggered tremor rather than triggered earthquakes, they suggest that prolonged triggered creep episodes could be relevant for both phenomena. In particular, triggered creep episodes could provide a physical explanation for the time delay commonly observed between passing seismic waves and distantly generated earthquakes.

Published online this week in the journal, “Nature Geoscience
,” the study, “Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes,” is the latest of ongoing research on the effects of large earthquakes on distant faults. While distantly triggered small earthquakes are relatively common, another recent study found no evidence for distantly triggered large earthquakes, at least during the first few days after a large event. The current study provides a possible mechanism to explain a range of time delays between a large distant event and triggered earthquakes.

Large, distant quakes can trigger changes in the San Andreas Fault

Distant earthquakes -- even thousands of miles away -- have far more impact on California's San Andreas Fault than scientists previously realized, new research has found.

Large quakes such as the magnitude 9.1 event in Sumatra that triggered tsunami waves across the Indian Ocean in 2004 and the 8.8 quake in Chile last year caused parts of the San Andreas Fault deep underground to suddenly slip, setting off small tremors, according to a study...

I saw some reports not long ago that showed Yellowstone caldera area reacting to the 9.1 in Japan by doing a slight upheaval.

All things are tied together, whether people want to admit that or not lol

Great info. Thanks for posting it.

SnF

Nice Find...


...But I read all that and what I took from it was...

The USGS has developed common sense... yay!! Good for them!

I wonder how much they spent in the pursuit to find "Common Sense"
I bet they will spend even more developing "Horse Sense"

OUCH... the tax payers wallets are hurting

corrected link for Nature Geoscience

We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes10, 11, 12, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes.

The USGS data is BS.

USGS Quote: "Researchers examining the San Andreas Fault in central California have found evidence that distant earthquakes can trigger episodes of accelerated (but still very slow) slip motion, deep on the fault."

How did they examine the San Andreas Fault in Central California and find evidence that they could prove distant earthquakes caused trigger episodes of accelerated (but still very slow) slip motion? That my friend is BS, and they cannot prove it with any sensitive seismic units that they have. IF they have such instruments, then let them tell us exactly what instrument it was, and let's see how really sensitive it really is; it's BS. Their statement here is all theoretical, it is not a scientific fact like they are presenting it to be.

USGS Quote: "While a sudden slip on a fault generates earthquakes capable of strong shaking, a fault can also slip slowly."

That is BS. The real factual statement should have been that "all faults move or slip slowly" until they have reached the fracture point. The other thing is that they have no equipment capable of proving this; if so please let us see it. Their statement here is all theoretical, it is not a scientific fact like they are presenting it to be.

USGS Quote: "Sometimes, these slow movements on a fault, known as creep events, are accompanied by a weak ground vibration known as a tectonic tremor, which can be detected on sensitive seismometers."

That is BS. It's not "sometimes" it's "most of the time there is slow movement on faults". They have never detected tectonic tremors as they state, if so, with what? Let's see their seismic charts that prove it. They can't be produced by the USGS since its all theoretical; not fact.

USGS Quote" "Using data from these seismometers, researchers from the U.S. Geological Survey and Georgia Institute of Technology examined the locations and timing of tremor activity following large distant earthquakes. In some cases, they found evidence that triggered slip and its associated tremor migrated along the length of the fault, and persisted long after the passage of seismic waves from the distant earthquake. The scientists hypothesize that distant earthquakes can act as a trigger for ongoing episodic creep events, sometimes altering their timing."

It's all BS, and theoretical, not scientific fact. If you read the above paragraph, you will see very quickly that everything they are basing all of their theoretical evidence on (not factual scientific evidence) is from examining data from "PAST ACTIVITY". If they had hard evidence like they are trying to pretend they have, then they would have been collecting their data before and during, not AFTER. Did you notice they finally use the word "HYPOTHESIZE", they should have been using that word all along.

I could keep on tearing up their BS paper, until it looked like they were complete idiots, but I'm in a hurry to go and get barbecue sauce for my barbecued ribs that have been cooking all day. MMMMMMMMMMMMMMMM

If you want to know why I'm an expert on all of this, and why I can stand up against idiots that throw their BS in front of the public about earthquakes, then go watch my 22 videos on YouTube about the real facts about earthquakes. My videos are not videos about theory, my videos are sciencific factual videos about what I have seen over and over again and again before earthquakes strike, and during their striking, and even up to a day and a half after they struck. Watch them in sequence, 1-22 to understand fully about detecting earthquakes of all magnitudes before they strike. Earthquakes of all magnitudes are very easy to detect before they strike, and that is a scientific fact, and has been so for over 15 years. Soon I'll put many more videos on YouTube.

Got to go, I'm hungry.

www.youtube.com...

reply to post by RussianScientists


Thank you for the post. I will watch your videos and see what I think.

I believe that when there is movement in one place, there has to be coming movement in another place to compensate.