Two small Earthquakes were recorded near Lake Oroville in the last 24 hrs, which appear to be a result of the fast lake level changes, and the subsequent release of pressure from water weight. Note the two yellow dots on the USGS map below:
Source of map, here
JD Elam notes on Facebook:
The predicted earthquakes due to extreme lake level change have started. 2 in the last hour. 300,000,000 pounds of water has been removed in two days, that will cause the earth to jiggle a bit. These were predicted and should not cause any problems.
The magnitude of the quakes were very small, 0.8 and 1.0 on the Richter Scale, and there does not appear to be any threat to the dam infrastructure.
jdp…A good chance of more earthquakes.
There is a rock quarry in the immediate area. Blasting perhaps? A magnitude 2.3 on the 8th; the same day as the concrete spillway flume damage began. A shock induced crack that rapidly opened up? A strange coincidence.
Go to USGS here. Click “Interactive Map”, select Satellite top right and zoom in. What time did the breach in the spillway appear?
If the quake is generated by blasting, then the USGS map states that on their daily map.
According to this the breach was discovered on Tuesday the 7th. The day before.
Native American lore states that massive rain caused by Gods Crying. Is California doing something to upset the Gods? Also Earthquakes are God’s way of shaking us awake for bad behavior. Any issues in California upsetting the God’s?
It’s the wrath of God punishing the State because we voted for Hillary instead of Trump.
Does anyone know if they filed the proper environmental impact statements? I think they are leaving themselves open for years of lawsuits.
If it is the dam construction you are referring to, there was not an EIS process when it was designed in the 1950’s and built in the 1960’s. That process did not begin until the 1970’s.
I’m pretty sure Mike is talking about the coming floods.
I’m going with Mothra.
You can’t go with Mothra, those two little fairies have already taken the available seats.
maybe California wont have to leave the USA after all..just break off from the continent
Yeah – continental drift. California continues going Left!
The predicted earthquakes due to extreme lake level change have started. 2 in the last hour. 300,000,000 pounds of water has been removed in two days, that will cause the earth to jiggle a bit. These were predicted and should not cause any problems.”
And if your wrong and people die? WHO GOES TO THE GAS CHAMBER????????
Those who said that California was soon to be all dessert.
Yeah, or the dam is shifting from undercutting.
Filling a discreet basin inert days with megatons of water (specific weight 1, but sheer mass does it)
must have Effects on geology in the blink of an eye.
Tell me.
Would water, resulting from the heavy rain after years of drought plus the high pressure dammed water, seeping down cause movement and lubrication in fault stresses thus increasing chances of stress relief?.
Massive quakes like that would send the anti-frakking community into a tail spin!
G. Karst,
The logic here escapes me.
you keep saying that the e-spillway is designed to fail.
That is not true.
It is designed to be overtopped before the rest of the dam gets overtopped.
Hence the lower level of the lip at that e-spill point as compared to the rest of the dam.
Why would the failure of this section of the dam actually ever be necessary, let alone desirable? If constructed in a way to really reflected the ultimate worst-case scenario, it could would fulfill its funtion of maintaining a level of about 901 or so feet, period.
It is certainly possible to design that emergency pathway in such a way, i.e. permit continuous drainage at that section without the undercutting erosion just seen.
That could include extending the e-spillway wall much farther down in the hillside (which would allow more surface erosion without undercutting problems, or by doing what the petition from 12 years ago asked for), ie in effect buildingg a reinforced auxiliary spill-way, rather than the unreinforced one.)
The inadequacy here is not due to a planned failure at this point, but because they pretended that what they built would withstand anything that could be thrown at it in a worst-case scenario. The federal and state responses, brushing of the concerns of the petition claimed exactly that, that the e-spillway is sufficiently strong for a worst-case, and nott needing more.
Self-serving worst-cases of course, so as not to spend more money.
Engineers of a different mind-set, take the worst-case, and then do a 1.5-2x increase (see Roebling comment below).
The mentality is similar to the Tappan Zee Bridge (whose intended life-time was a reidiculously short period, and being of the same type of construction as the Minneapolis bridge, we see what that can mean).
I mention the TZB, because its from the same era of design as this dam.
Compare that to the Brooklyn Bridge.
Still standing after 133 years, because Roebling set no date for its demise, it was supposed to last indefinitely, and still going strong.
When they finally replaced the main suspension cables after a century, they were found to be in such good shape as to have not needed it.
And question again out of curiosity, how far below the 901 ft line does the main spillway drain?
If you cannot understand Trainer’s excellent video… I don’t know what else to say?!
https://dailytimewaster.blogspot.com.es/2017/02/breach-of-auburn-coffer-dam-in-1986.html
Thx to Trainer February 16, 2017 at 1:28 pm GK
They where small yes, but think when they are exaggerated by global warming or worse with climate change.
No one knows where it can lead, but for sure it might be much worse when all is concidered.
If the sky is not falling down, maybe the ground is.
G. Karst –
First off, I really enjoyed the video of controlled failure of an erosion plug at Auburn coffer dam. Every engineering geology and geotech engineer student needs to see it. However, I suggest that the Oroville scenario is somewhat different.
I have spent some time studying an aerial photo taken after the emergency spill. Whereas the Auburn coffer dam plug was clearly introduced fill, the Oroville emergency spillway appears to be built on insitu rock. This suggests that the design was based around a scenario where a sheet of water would spill down slope as though the surface was similar in nature to concrete.
The structure of the rock surface and the embankments of the erosion channels are consistent with metamorphic rock. There appears to be an upper bed (layer) through which the water cut channels rapidly. The floor of the channels appear to be a harder material. I say this because the channel walls are of a rather regular depth. This is consistent with metamorphosed lava flows, or subsurface sills – or even sedimentary sequences i.e. different layers with different properties. There is also the possibility that there is no layering and that the water cut though the weathered (rotten) “rind”. But, usually weathering is very inconsistent in depth.
Therefore, I speculate using this limited evidence that Oroville was not designed with an erosion plug. It was designed with a natural spillway surface that proved to be too weak. The danger could be that once the concrete structure was undercut there would be a rapid catastrophic failure resulting in a wall of water rushing downstream, rather than a progressive discharge as seen at the Auburn coffer dam.
Just one man’s (geologist) analysis 🙂
Do not get hung up on the word “plug”. The plug can either be natural or man made. It varies. in this case the majority of the plug is the emergency spillway itself. ALL dams are big plugs. in an extreme emergency Do you want to pull the big plug or the small self sizing plug
It took civilization centuries to learn a important reality:
ALL DAMS WILL EVENTUALLY FAIL
So we put out tenders for a new dam and powerhouse and we get two applicants:
– a geologist and an engineer. The geologist says he is building the dam on billion year old bedrock’s and he will build a structure which CANNOT fail, even when and with overtopping. I cannot tell you how it will fail because… IT WILL NOT FAIL
– an engineer says ALL DAMS CAN FAIL, if the unforeseen happens, and it will fail quickly if overtopped. Mine will fail like this and you will be back in business shortly after.
Who are you going to hire?
Well… for centuries we went with the geologists. Google famous historical dam failures to find out how that worked out.
Modern earthen dams have gone with the engineer. Just one man’s observation. GK
GK
Who would I employ? Well, find me a dam construction team that does not include:
Engineers (electrical, fluid dynamics, mechanical, structural, geotechnical)
Geologists: Engineering, structural, seismologists, geophysical
Others: Hydrology e.t.c.
The profession of engineering geology was first acknowledged in the US. It is an essential part of any team to analyse and predict the behavior of sub-surface materials
Remember that a dam has to be linked to natural materials. Below is an example of what happens when the geological studies get it wrong. In this case a slope toe was weakened by saturation. As I recall there was some seismic activity involved too