[ Roll & Rock ] [ Main Menu ]
22964
From: georg, [DNS_Address]
Subject: it seems the answer is yes, excessive rainfall lubricates faults
|
and could lead to earthquakes ... someone posted the cause and effect from the big storm 84 years ago in that area and the resulting earthquake a year or so later |
Responses:
[22993] [22966] [22970] [22973] [22975] [22974] [22978] [22979] [22981] [22994] [22965]
22993
From: SyzygyWill, [DNS_Address]
Subject: Re: it seems the answer is yes, excessive rainfall lubricates faults
|
Also, there is the weight of the water. It could either slow something down, that was going to happen, or help to trigger something that may have happened later. In the case of Central California what they are calling Lake Tulare is adding millions of tons, plus what is saturating the water table below, of weight that is normally not on that Plate. It is hard to say if it's beneficial right now, or not, but was is certain is that the fluctuation of this weight not-there-not is well, poking the bear. And you must never poke the bear. |
Responses:
None
22966
From: Skywise, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
|
"Rain itself has little impact on earthquake genesis, unless it is karstified limestone..." "...if there is a rain-induced increase in seismicity in California, it will be localized in areas with carbonates, or around reservoirs..." "...earthquakes due to rainfall only really occur in convergent tectonic environments..." "...this is not the case in California..." Brian |
Responses:
[22970] [22973] [22975] [22974] [22978] [22979] [22981] [22994]
22970
From: georg, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
| well, certainly, since its you |
Responses:
[22973] [22975] [22974] [22978] [22979] [22981] [22994]
22973
From: Skywise, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
|
I'm just quoting the article you posted. Brian |
22975
From: georg, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
URL: http://earthboppin.net/talkshop/rollem/messages/22946.html
|
this scenario shows tropical storm in 1939 followed by El Centro earthquake in 1940 ... not proof of cause and effect but certainly worth considering ... for me that is ... for a genius like you probably not so much |
Responses:
None
22974
From: georg, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
|
and you can't imagine any other outcome from lots of water running down slopes and soaking into cracks and so forth ... nothing about water lubricating existing faults or hidden faults ... nothing like that ... very interesting thought process ... it blocks so many scenarios that might be possible ... I tend to have an inquisitive mind, but that's just me |
22978
From: Skywise, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA
|
Oh, I can envisage scenarios where rain can affect quake activity. But they're going to be rare circumstances. Not something that we can say "rain here, quake there" and call it a day. Keep in mind quakes happen many, if not tens of kilometers under ground. How does water on the surface make it that far down? Can it even do so? How long does it take? I go back to my original questions to the board. How many storms have there been in Southern California that were NOT followed by any significant quake activity? How many significant quakes were NOT preceded by heavy storms? Add to that, compare to how many times there was a correlation. Very small compared to the total, right? So how is it reasonable to say "rain here, quake there"? I just don't think it is reasonable based on the factual historical record. Sure, tropical storm in 1939. Yes, big quake in 1940. How do you know that is anything but a coincidence? So yeah, I questioned the claim. You replied with a link, and I read it fully expecting it to be some crazy argument that there is a significant link between big wet and big shake. Instead, the article you shared was a reasoned argument against - possible, maybe in rare circumstances, but unlikely, especially in California. Brian |
22979
From: MikeinIndioCA, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA- ? For
|
Hi Brian, What's your take on the recent published study linking past flooding in the Coachella Valley and quakes specifically on the SAF?. Seems they have a strong correlation between the two and it certainly provides a possibly explanation as to why the Southern San Andreas as been so quiet |
22981
From: Skywise, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA- ? For
|
Thanks for the reference. Too bad I don't have access to the full article, so I can only comment on the abstract. Basically, they are saying that the sudden filling of the lake might be a trigger for quakes on the fault. At least in theory. They can only model the idea. Honestly, it makes sense to me. It's the quick rate of change of the weight of the water when the lake fills that's the problem. By analogy, you can set a five pound weight gently on a sheet of glass. But drop even a one pound weight from 6 inches and the glass is likely to shatter. This is similar to the induced seismicity observed during the filling of reservoirs. But the question seems to be, did the lake flood first, thus causing the earthquakes? Or did earthquakes cause changes in river course causing the lake to flood or dry up? The Wikipedia article on Lake Cahuilla references an article to the latter case of quakes coming first, but I cannot find access to the full text. In any case, I think we can agree that this scenario is a far cry from a tropical storm like Hilary triggering a significant quake. In the case of Lake Cahuilla I think we're talking about a far larger amount of water than what one gets from even a bull blown hurricane dumping inches of rain. Brian |
Responses:
[22994]
22994
From: SyzygyWill, [DNS_Address]
Subject: Re: it seems the answer is yes, BUT VERY UNLIKELY IN CALIFORNIA- ? For
| Yes, any fear from a tropical storm triggering an earthquake in SoCal should be dismissed as in March of 1978 three Tropical storms hit Ventura / Santa Barbara Counties. I lived in Ventura County and it was bad, lots of rain, lots of wind, most trees were knock down, but don't recall even hearing of any small quakes or swarms. I may be wrong, it should be able to be researched. |
Responses:
None
22965
From: Jeff/Lake Almanor,CA, [DNS_Address]
Subject: Lets look at Hot Creek Geologic Site, Long Valley Caldera
URL: https://www.fs.usda.gov/recarea/inyo/recarea/?recid=20414
|
Hot Creek is a place to marvel at geology in action. Boiling water bubbling up from the creek bed, fumaroles and periodic geyser eruptions at Hot Creek attest to the chamber of hot magma which lies about three miles below the surface of the earth in this area. The steam you see along the Hot Creek drainage is created when water percolates deep into the ground and enters a complex underground plumbing system. The water is heated and pressurized before it rises to the earth's surface. It is believed this journey takes around 1000 years. Earthquakes can cause sudden geyser eruptions and overnight appearances of new hot springs at Hot Creek. Water temperatures can change rapidly, and so entering the water is prohibited. |
Responses:
None
[ Roll & Rock ] [ Main Menu ]