Jcolvin2 wrote: ↑
Mon Oct 22, 2018 1:15 pm
Jcolvin2 wrote: ↑
Sun Oct 21, 2018 4:51 pm
It seems like Seattle is also overdue for a quake (but we humans have a hard time understanding how probability works). Over the last few days, I have seen a large number of injured wild animals (three raccoons in two separate incidents and a great horned owl!). I know some believe that erratic animal behavior may be a harbinger for a coming earthquake, but I hope it is just coincidence in this case.
After I made the above post, several 6.5+ magnitude quakes happened last night off the coast of Vancouver Island:
Link to CBC Article re Vancouver Island Earthquakes
I've believed for a long time that animals can (sometimes) tell us (if we're listening/watching) about an imminent earthquake. I have no firm beliefs about what kind of animals or how far in advance animals are aware.
The USGS has this (and this is all plus 3 references from the 1980s and 2000):
Animals & Earthquake Prediction
The earliest reference we have to unusual animal behavior prior to a significant earthquake is from Greece in 373 BC. Rats, weasels, snakes, and centipedes reportedly left their homes and headed for safety several days before a destructive earthquake. Anecdotal evidence abounds of animals, fish, birds, reptiles, and insects exhibiting strange behavior anywhere from weeks to seconds before an earthquake. However, consistent and reliable behavior prior to seismic events, and a mechanism explaining how it could work, still eludes us. Most, but not all, scientists pursuing this mystery are in China or Japan.
We can easily explain the cause of unusual animal behavior seconds before humans feel an earthquake. Very few humans notice the smaller P wave that travels the fastest from the earthquake source and arrives before the larger S wave. But many animals with more keen senses are able to feel the P wave seconds before the S wave arrives. As for sensing an impending earthquake days or weeks before it occurs, that's a different story.
A once popular theory purported that there was a correlation between Lost Pet ads in the San Jose Mercury News and the dates of earthquakes in the San Francisco Bay area. A thorough statistical analysis of this theory, published in California Geology in 1988, concluded that there was no such correlation, however.
Another paper published in a scientific journal in the U.S. on this subject by a respected scientist in 2000 is summarized here...
The paper poses this question: Is it reasonable for a seismic-escape behavior pattern to evolve, and can such a genetic system be maintained in the face of selection pressures operating on the time scales of damaging seismic events? All animals instinctively respond to escape from predators and to preserve their lives. A wide variety of vertebrates already express “early warning” behaviors that we understand for other types of events, so it’s possible that a seismic-escape response could have evolved from this already-existing genetic predisposal. An instinctive response following a P-wave seconds before a larger S wave is not a “huge leap”, so to speak, but what about other precursors that may occur days or weeks before an earthquake that we don’t yet know about? If in fact there are precursors to a significant earthquake that we have yet to learn about (such as ground tilting, groundwater changes, electrical or magnetic field variations), indeed it’s possible that some animals could sense these signals and connect the perception with an impending earthquake.
However, much research still needs to be done on this subject. The author suggests establishing a baseline behavior pattern that can be compared with reactions of various environmental stimuli, and then testing various potential stimuli in the laboratory. Of course, the presence of these stimuli still needs to be researched with regard to precursory phenomena preceding an earthquake, for if these signals aren’t present in the environment before an earthquake, a connection is irrelevant.
From an article written in 2012 and updated in 2018:
https://www.livescience.com/32156-can-a ... uakes.html
To get to the bottom of this question, Woith and his colleagues evaluated more than 700 published reports of unusual behavior among 130 species, including insects, birds, fish and mammals (mostly cats, dogs and cattle) from 160 earthquakes, he said.
The records included all kinds of behaviors, including a tiger that reportedly got depressed before an earthquake, Woith said.
Despite the vast number of alleged incidences, good information was sparse, Woith said. "A major surprise for us was that the large majority of the published claims were built on poor observational data [meaning most people did not properly observe the animals before, during and after the earthquake], which did not stand as statistical scientific proof," Woith said.
The researchers found that 90 percent of all reported cases happened within 62 miles (100 kilometers) of the epicenter and within 60 days of an earthquake. Then, they examined when and where foreshocks had happened in the region. The resemblance was remarkable, they found.
"The space-time pattern of animal precursors and foreshocks is strikingly similar," Woith said. "From this, we concluded that at least some of the abnormal animal behavior might simply be related to foreshocks."
A map showing locations of the recent earthquakes in relation to the Juan de Fuca Plate :
. . .
The tremors occurred at the Pacific Ocean-floor ridge that separates the Juan de Fuca Plate and its western neighbor, the Pacific Plate. But they do not necessarily signal an impending 9.0-magnitude earthquake, or a so-called “big one,” that geologists predict will hit Pacific Northwest, according to Tobin. That earthquake is expected to occur along the Cascadia fault line on the eastern side of the Juan de Fuca Plate.
. . .
The largest quake was relatively shallow, at about 6 miles, and it struck about 149 miles west of Tofino, B.C. Deeper earthquakes can be felt further away from where they occur, which explains why few people in the Northwest felt Sunday’s tremors, said Don Blakeman, a geophysicist with the U.S. Geological Survey who is based in Golden, Colorado.
The earthquakes did not put any additional stress on the Cascadia Subduction Zone, where the big earthquake is expected to take place. That zone lies along the fault line where tension is mounting under the earth’s crust and where cities like Seattle are located. The new tremors were recorded just on the bou
. . .
Above map and quote from the Seattle Times
This link is for a series of slides (Power Point-y) with a number of examples of animal predictions; the link to a PBS documentary on animals and disasters at the end has expired. Dated 2010.
https://faculty.washington.edu/tswanson ... iction.pdf
IMHO, the dead and injured animals that you saw aren't related to the earthquakes because the earthquakes were too far away and on a different plate (I haven't looked specifically for information about whether animals can sense quakes in a different plate). The shallow depth also makes it less likely.