Scientists Discover How Giant Earthquakes Start

[Swordsmyth]

Scientists at Los Alamos National Laboratory have found that most moderate and large earthquakes are preceded by tiny earthquake clusters, sometimes even weeks before the main shock, according to the LA Times.

So much for the 'relieving pressure' argument.
"One of the biggest questions in earthquake seismology is how earthquakes get started," said the study's lead author, seismologist Daniel Trugman. "We’re finding that most, if not all, of [significant] earthquakes are preceded by foreshocks that we can detect" using a new computing technique.

Previously, scientists observed that only half of all moderate quakes had precursor smaller events. Now, this new study of earthquakes in Southern California of at least magnitude 4 between 2008 and 2017 finds that at least 72% of them had earlier, smaller quakes. -LA Times

"Elevated foreshock activity is pervasive in Southern California," concludes the study.
"It is surprising" says co-author Zachary Ross, an assistant professor of geophysics at Caltech, adding "It’s important for understanding the physics of earthquakes. Are they silent until this big event? Or is there a weakening process of the fault, or some evidence that the fault is changing before this larger event?"
It sure looks that way - and according to the study, foreshock sequences can start anywhere from three days to 35 days ahead of the mainshock.


More at: https://www.zerohedge.com/news/2019-...thquakes-start

https://twitter.com/dutchsinse/statu...12511357243393

[TheTexan]

This is some ground breaking research

[Danke]

This is some ground breaking research

[Origanalist]

So much for the 'relieving pressure' argument.

How does this disprove the relieving pressure argument? Just because some smaller quakes occur and there is some preliminary movement doesn't mean the bigger quakes aren't relieving built up pressure.

But it is good to know we may have more warning than we thought.

[Occam's Banana]

This is some ground breaking research

[Zippyjuan]

How does this disprove the relieving pressure argument? Just because some smaller quakes occur and there is some preliminary movement doesn't mean the bigger quakes aren't relieving built up pressure.

But it is good to know we may have more warning than we thought.

No, it doesn't disprove the relieving pressure argument. Try crushing a cookie very slowly. Increase pressure on it. First little bits start to break off- small quaked. Then, it finally snaps- the big quake. More pieces crumble off after that- the aftershocks.

It doesn't help predictions either. Foreshocks can happen a short or long time before a larger quake- and you can have foreshocks without a major quake developing. Just means a location should be watched. There are thousands of small quakes every day all over the world but not all lead to larger ones.

foreshock sequences can start anywhere from three days to 35 days ahead of the mainshock.

https://earthquake.usgs.gov/learn/facts.php

It is estimated that there are 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, and 100 of them cause damage.