Earthquakes, volcanoes and tsunamis

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There was a 6.5 in Challis, Idaho. I live in Boise, so it was just rocking my building. Still freaked out, it was my first experience.
 
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GTvsForza
There was a 6.5 in Challis, Idaho. I live in Boise, so it was just rocking my building. Still freaked out, it was my first experience.
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Ya we felt it here in SLC, it wasn't bad but my computer monitor was definitely swaying back and forth. Hopefully, the damage isn't too bad. Thankfully, it looks like the epicenter was in a pretty remote area so that should help.

And I agree, it's a bit scary. When we had ours two weeks ago, it was the first time I'd experience one that had some actual power to it.
 
GTvsForza
There was a 6.5 in Challis, Idaho. I live in Boise, so it was just rocking my building. Still freaked out, it was my first experience.
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People in the Okanagan Valley in BC are reporting feeling it....I didn’t feel anything :lol: Must have missed it.
 
GTvsForza
There was a 6.5 in Challis, Idaho. I live in Boise, so it was just rocking my building. Still freaked out, it was my first experience.
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First Time.jpg


- A Californian
 
GTvsForza
Funny enough, I was born in California. I don't think I ever felt an earthquake, except for those silly simulations at Universal Studios or the Science museum.
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Outside of the 7.1 we had over the 4th of July and some random small tremors over the years, I've never felt much of anything in my almost 38 years. The 1994 Northridge quake, which I live fairly close to the epicenter, I slept thought that one.
 
Looks like southern California just got a shaking. Initial quake of 4.9, then a bunch of aftershocks ranging from 2.6 to 3.7. Looks to be centered in the mountains west of the Salton Sea.
 
There was a 4.6 aftershock Wednesday night, which was probably the reason I woke up at midnight. Haven't felt anything since...
 
 
Joey D
I'm going to need some help because I don't see anything out of the ordinary. In the last 30 days, we've only had 12 significant quakes with the strongest being 6.8 in Indonesia.
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I'm more concerned about the "Ring of Fire", the clusters in the Alaska region and Southern California. San Diego was rattled by a 4.5. Small quakes are occurring under Mt. Baker, Mt Rainier and Mt St Helens, all potentially active volcanos. Yellowstone is having record geysers, and the New Madrid fault is more active than its been for decades. Didn't you have a recent quake there in the Salt Lake area that was out of the ordinary?
 
Dotini
I'm more concerned about the "Ring of Fire", the clusters in the Alaska region and Southern California. San Diego was rattled by a 4.5. Small quakes are occurring under Mt. Baker, Mt Rainier and Mt St Helens, all potentially active volcanos. Yellowstone is having record geysers, and the New Madrid fault is more active than its been for decades. Didn't you have a recent quake there in the Salt Lake area that was out of the ordinary?
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We did and we continue to have aftershocks too. However, an earthquake along the Wasatch fault is common enough where it's not too unusual for it to happen. They hit somewhere between 20-50 years, which in a geological time scale is nothing.

Most of the earthquakes occurring around the world are pretty minor with the biggest one being in Indonesia. I don't think there's any cause for concern at this time regarding the earthquakes because they're mostly occurring around known faults, have minimal impact to structures, and are mostly less than 4.5 in magnitude.
 
A few hours ago, a shallow 7.1 earthquake struck northeast of New Zealand, only 5 miles deep. No tsunami warning.
 
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tsunani threat in effect

This is the Alert I received on my phone
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EVALUATION
----------

* AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.5 OCCURRED IN
THE ALASKA PENINSULA AT 0613 UTC ON WEDNESDAY JULY 22 2020.

* BASED ON THE PRELIMINARY EARTHQUAKE PARAMETERS... HAZARDOUS
TSUNAMI WAVES ARE POSSIBLE FOR COASTS LOCATED WITHIN 300 KM
OF THE EARTHQUAKE EPICENTER.
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So..update on the Alaska quake. Tsunami warning was canceled, none or anything perceived as dangerous was not detected.

Damage has been reported in several communities *photos courtesy of Facebook*

Sand Point
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Cold Bay
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Homer residents evacuating in case of Tsunami
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A paper, which appears to have been accepted and published by the journal Nature, on the correlation between solar activity and large earthquakes worldwide.


Abstract
Large earthquakes occurring worldwide have long been recognized to be non Poisson distributed, so involving some large scale correlation mechanism, which could be internal or external to the Earth. Till now, no statistically significant correlation of the global seismicity with one of the possible mechanisms has been demonstrated yet. In this paper, we analyze 20 years of proton density and velocity data, as recorded by the SOHO satellite, and the worldwide seismicity in the corresponding period, as reported by the ISC-GEM catalogue. We found clear correlation between proton density and the occurrence of large earthquakes (M > 5.6), with a time shift of one day. The significance of such correlation is very high, with probability to be wrong lower than 10–5. The correlation increases with the magnitude threshold of the seismic catalogue. A tentative model explaining such a correlation is also proposed, in terms of the reverse piezoelectric effect induced by the applied electric field related to the proton density. This result opens new perspectives in seismological interpretations, as well as in earthquake forecast.
---------------------------
Conclusions
This paper gives the first, strongly statistically significant, evidence for a high correlation between large worldwide earthquakes and the proton density near the magnetosphere, due to the solar wind. This result is extremely important for seismological research and for possible future implications on earthquake forecast. In fact, although the non-poissonian character, and hence the correlation among large scale, worldwide earthquakes was known since several decades, this could be in principle explained by several mechanisms. In this paper, we demonstrate that it can likely be due to the effect of solar wind, modulating the proton density and hence the electrical potential between the ionosphere and the Earth. Although a quantitative analysis of a particular, specific model for our observations is beyond the scope of this paper, we believe that a possible, likely physical mechanism explaining our statistical observations, is the stress/strain pulse caused by reverse piezoelectric effects. Such pulses would be generated by large electrical discharges channeled in the large faults, due to their high conductivity because of fractured and water saturated fault gauge. The widespread observations of several macroscopic electro-magnetic effects before, or however associated to large earthquakes, support our qualitative model to explain the observed, highly statistically significant, proton density-earthquakes correlation. It is important to note that our hypothesis only implies that the proton density would act as a further, small trigger to cause the fracture on already critically charged faults, thus producing the observed large scale earthquake correlation. Such a small perturbation would add to the main factor producing worldwide seismicity, which is tectonic stress.

https://www.nature.com/articles/s41598-020-67860-3
 
7.5 just hit off the coast of Alaska. Several others in the 5's afterwards. Tsunami warning was issued.

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Following up on @R1600Turbo


Tectonic Summary

The October 19, 2020, M 7.5 earthquake southeast of Sand Point, Alaska (south of the Alaska Peninsula), occurred as the result of strike-slip faulting near the subduction zone interface between the Pacific and North America plates, either within the upper (North America) Plate or within the downgoing (Pacific) slab. The preliminary focal mechanism solution indicates rupture occurred on either a moderately dipping right-lateral strike-slip fault striking towards the NNW or on a steeply dipping left-lateral strike-slip fault striking towards the east, and therefore that this earthquake was not a thrust event on the plate interface itself. At the location of this event, the Pacific plate converges with North America to the northwest at a rate of about 64 mm/yr, subducting at the Alaska-Aleutian Trench 100 km to the southeast of the earthquake. This event is an aftershock of the M 7.8 earthquake that occurred on July 22, 2020.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Strike slip faulting events of the size of the October 19, 2020 earthquake are typically about 130x25 km (length x width).

Large earthquakes are common in the Alaska-Aleutian subduction zone. Since 1900, 8 other earthquakes M7 and larger have occurred within 250 km of the October 19, 2020 event, including the July 22, 2020 M 7.8 mainshock of this sequence. An updated aftershock forecast for the July 22, 2020 M 7.8 sequence, that includes the occurrence of this October 19th, 2020 earthquake, can be found here. The largest of these was a M8.6 earthquake on April 1, 1946, which generated a large tsunami that caused destruction and loss of life both locally on Unimak Island and more distantly at Hilo, Hawaii. The Alaska-Aleutian Trench also hosted the second largest earthquake recorded by modern seismic instrumentation, the M9.2 March 27, 1964 earthquake, which ruptured to within about 350 km of this event.

The majority of large earthquakes in this area are thrust events on the plate interface, unlike the strike-slip event of October 19, 2020. The stretch of the Alaska-Aleutian subduction zone beneath the Shumagin Islands has not ruptured in a historical great (M>8) earthquake. This observation led to definition of the ‘Shumagin Gap’ in the context of seismic gap theory, which proposes that fault sections that have not slipped for the longest elapsed time will be the site of future earthquakes. The interpretation that the Shumagin Gap can host extremely large earthquakes is clouded by 1) geodetic observations, which show that the Shumagin Islands and neighboring Sanak Island are above a section of the subduction interface that is very poorly coupled and storing very little elastic strain; and 2) geologic observations, which have documented little land level change and tsunami inundation since ~3,000 years ago on Simeonof Island in the Shumagins.
 
There was a 3.6 earthquake off the coast of New Bedford in southeast Massachusetts. It was the strongest in the area in decades. And I can now say I can sleep through an earthquake.
 
4.4 earthquake happened at Kilauea happened to change the volcano alert from green to red.
Light ashfall was reported but has since diminished.
 

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