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However in order to over top, it would need the incoming water to exceed the outgoing water through the spillway, and over the weir A 1700ft long weir with 30ft of head can pass appx 86k cfs. Downstream of it, wouldn't like to guess. So if we assume the primary spillway can take 150k cfs and the emergency spillway 86k, that means the incoming COULD THEORETICALY get as high as 236k without it getting high enough to over top. That also doesn't take account of the main spillway probably being capable of taking way more than 150k. View Quote I think its much higher. I found a document on weirs that says the discharge coefficient increases dramatically for high head situations. A 1700' weir with 20' of head can be upwards of 500,000 cfs. I posted the link back a few pages, not sure I can find it again. |
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However in order to over top, it would need the incoming water to exceed the outgoing water through the spillway, and over the weir A 1700ft long weir with 30ft of head can pass appx 86k cfs. Downstream of it, wouldn't like to guess. So if we assume the primary spillway can take 150k cfs and the emergency spillway 86k, that means the incoming COULD THEORETICALY get as high as 236k without it getting high enough to over top. That also doesn't take account of the main spillway probably being capable of taking way more than 150k. View Quote |
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At least he's using his right hand. Did they run out of gloves? And tongs? View Quote View All Quotes View All Quotes Quoted:
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Here's some tasty fries for your kid. Dam refugees http://i.dailymail.co.uk/i/pix/2017/02/14/14/3D3154F700000578-4221808-Sharing_At_the_Gurdwara_Sahib_Sikh_Temple_in-m-15_1487081948054.jpg Did they run out of gloves? And tongs? He's not a Mooslem. |
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Yeah same here, not seeing any bubbles... View Quote View All Quotes View All Quotes Quoted:
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Looks more like a reflection of the sun to me. Yeah same here, not seeing any bubbles... I saw them. The camera man noticed them too because he zoomed in quickly for better close ups. |
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Looks more like a reflection of the sun to me. View Quote View All Quotes View All Quotes Quoted:
Looks more like a reflection of the sun to me. |
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Just started watching, but this looks like they're working in earnest in the main e-spill area: https://www.youtube.com/watch?v=ux9MSHoVL2g View Quote Thanks for posting this! At 17:00 it looks as if the concrete pumper is dispensing on the storage side of the e-weir near the parking lot. Any shots of what is going on in that area? I am looking around, but not much in the way of aerial images with flight restrictions in place. (Apologies if already mentioned.) |
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Looks more like a reflection of the sun to me. Looks like reflection to me as well... |
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If that lake, Oroville, Comanche, and Don Pedro were in Texas I'd be moving to Texas RFN. The only thing holding me back from Texas is the lack of salmon fishing there. View Quote |
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Looks more like a reflection of the sun to me. Look at the white spots there are at least 2 of them that suddenly appear =Bubbles |
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I think its much higher. I found a document on weirs that says the discharge coefficient increases dramatically for high head situations. A 1700' weir with 20' of head can be upwards of 500,000 cfs. I posted the link back a few pages, not sure I can find it again. View Quote View All Quotes View All Quotes Quoted:
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However in order to over top, it would need the incoming water to exceed the outgoing water through the spillway, and over the weir A 1700ft long weir with 30ft of head can pass appx 86k cfs. Downstream of it, wouldn't like to guess. So if we assume the primary spillway can take 150k cfs and the emergency spillway 86k, that means the incoming COULD THEORETICALY get as high as 236k without it getting high enough to over top. That also doesn't take account of the main spillway probably being capable of taking way more than 150k. I think its much higher. I found a document on weirs that says the discharge coefficient increases dramatically for high head situations. A 1700' weir with 20' of head can be upwards of 500,000 cfs. I posted the link back a few pages, not sure I can find it again. Weir formulas: Fluid Mechanics |
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Nah, I think 500,000 ac is about right. The surface area is a bit over 15,000 acres, multiply that by 30 feet, assuming that is the lowest spot on the weir and you come close to 500,000 acre/feet. The entire capacity of the dam is 3,500,000 acre feet. View Quote View All Quotes View All Quotes Quoted:
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Does anyone really know how much water escapes if the E spillway breaches? To my untrained eye it seems plausible that the main spillway gates would be in great jeopardy. At what level will the bedrock hold? Can any section of the weir hold if there is a break? Add a zero to that. Half million acre feet + whatever the height above it is at the time. Nah, I think 500,000 ac is about right. The surface area is a bit over 15,000 acres, multiply that by 30 feet, assuming that is the lowest spot on the weir and you come close to 500,000 acre/feet. The entire capacity of the dam is 3,500,000 acre feet. |
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I've been looking at the levels, and I think you're right. These fucking idiots were so stunned/shocked/tunnel visioned about the drought years that they didn't do releases all along as they ought to have for the flood management function. They were too worried about not having enough water despite all the evidence that they would have more than they could ever use or hold. IN other words, they neckbearded the fucking operation of these dams. View Quote View All Quotes View All Quotes Quoted:
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They can only use the spillway once the lake is up to the bottom of the gates, there seems to be some question about the elevation but it's definitely between 811' and 850' The spillway failed more or less the first time they loaded it hard in the last several years, if I've read the charts right the lake never got high enough to put any significant flow through the spillway during the drought. It's all on their half-assed spillway repair that seems to have missed that there was a void forming under the cracks they just patched over. The had a perfect opportunity to repair that during the drought and failed to do so. They should have been running the power house at capacity 24/7 since mid December. Instead, they wanted the water level to go up, knowing it would anyway. When bad management meets bad maintenance and hopes meet reality, we see Catastrophe, which this will be. NorCal is fucked before July. Lake Shasta is currently flooding towns trying to get their storage down below 98% since that snow hasn't melted and there's a lot of rain on the way. There is NO REASON this should be a problem. Nature hasn't done anything it hadn't done prior to this, mismanagement and maintenance fucked it. I've been looking at the levels, and I think you're right. These fucking idiots were so stunned/shocked/tunnel visioned about the drought years that they didn't do releases all along as they ought to have for the flood management function. They were too worried about not having enough water despite all the evidence that they would have more than they could ever use or hold. IN other words, they neckbearded the fucking operation of these dams. Exactly..while the dam was built for 3 reasons, flood control, power generation and watershed, it was only supposed to run at about 70% capacity except for the spring snow melts..instead the Cali gov got desperate for more and more water and started running these dams as close to max capacity as they could...then after this "drought" when they did get rain, they tried to neck beard it all..most likely worried that the "wet" season wasn't going to live up to expectations, and they figured, well we can always drain it as needed to maintain that max capacity..except their shitty lack of maintence caught up to them... |
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Yup. I've brought up the Teton damn since the early pages of this thread because images of that still haunt my memories as a kid. I grew-up in western Wyoming... just over the "hill" from that carnage and remember the stories of how that went down and the pictures. View Quote Many of my relatives lost some or all of their homes, including my grandmother. Some of my earliest childhood memories involve seeing brown mud all over the walls and possessions in their homes. And the smell. I wasn't quite 3 years old at the time. |
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KCRA Live Heli feed View Quote It is impressive the scale of the dam and situation as a whole when you consider the size of the helicopters and bags of rocks. Those aren't little helicopters and they look absolutely tiny in comparison to the dam, the weir, and the problem as a whole. |
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View Quote View All Quotes View All Quotes Could be divers inspecting but don't think you could see that from a helicopter.... |
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Here's what I could find, I don't think it's grouted at the spillway level, though: https://www.AR15.Com/media/mediaFiles/41058/oroville-cross-section-146669.jpg View Quote When building this dam they looked for solid rock, not being able to see through it. It is standard procedure to drill into the rock to assure that it is in fact solid. And not a huge mud slip possibly just below surface. Grouting the probe holes and doing a grout curtan at the bottom where I would expect the least decomposed more solid of all the rock. Walls all the way up would likely be the same, drilled and grouted . Holes filled at the least , cracks and voids filled that would otherwise fill with moisture and expand contract. Just my 2 cents from Dams,tunnels. Utah water projects. early 80's |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote That's normal. Nothing to worry about. From what I've read, it's a way to keep water from going under the spillway and undermining it. Kinda like what happened a bit downstream from that photo. |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote that is by design |
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Nah, I think 500,000 ac is about right. The surface area is a bit over 15,000 acres, multiply that by 30 feet, assuming that is the lowest spot on the weir and you come close to 500,000 acre/feet. The entire capacity of the dam is 3,500,000 acre feet. View Quote They rate it at 3.5 million AC now, but the original plaque posted earlier states only 3 million AC...they are running it to max capacity with no "flood control" room left.. |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote |
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Interesting that they've restored vehicle access to the catch basin and are bringing in mining truck loads of rock. I'm guessing the plan is to fill the washouts with rock and possibly to line the front edge of the weir with rock as well. I wonder will they be able to concrete all that in place before the rains come? View Quote View All Quotes View All Quotes Quoted:
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Just started watching, but this looks like they're working in earnest in the main e-spill area: https://www.youtube.com/watch?v=ux9MSHoVL2g |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg that is by design Seems like it could be undermining more of the flume! |
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It is impressive the scale of the dam and situation as a whole when you consider the size of the helicopters and bags of rocks. Those aren't little helicopters and they look absolutely tiny in comparison to the dam, the weir, and the problem as a whole. View Quote I noticed that yesterday when I was watching. They were putting those superbags in that little hole, then I remembered those superbags are the size of a pallet cubed. And they looked little...... |
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I think its much higher. I found a document on weirs that says the discharge coefficient increases dramatically for high head situations. A 1700' weir with 20' of head can be upwards of 500,000 cfs. I posted the link back a few pages, not sure I can find it again. View Quote Flow over a spillway increases as a function of height over the crest non-linearly, with a power greater than 1. 20 feet over the spillway would be hundreds of thousands of cfs. Its hard to estimate the flow over the spillway because that spillway is a mess. You have a nice ogee crest at the gate house end that tails off into what appears to be nothing more than a retaining wall where the parking lot starts. They must have had budget problems or time constraints at the end because the engineers would never have designed a spillway intended to survive without anchoring of the spillway at both ends and control of flow to the crest of the spillway on both ends. The emergency spillway will fail at the parking lot end and unzip all the way to the gate house if they let any appreciable amount of flow over the emergency spillway. |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote I think there are pipe outlets there. Its pretty symetrical from side to side. I'm not an engineer, but I suspect its designed to modify the flow characteristics of the water at the corners/edges of the drain basin... |
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Weir formulas: Fluid Mechanics http://media.nbcbayarea.com/images/652*454/Bob+Weir+700_0917.jpg View Quote yes I know, I found a paper that provided some documentation of much higher Cd for very high head discharges over rectangular weirs. They example they used was pretty similar geometry to the oroville espillway. ETA: Not saying they ought run off and do it - just that topping the dam with water is a non-realistic scenario. If the weir could take the load, you couldn't get enough inflow into the system to top the dam. or, The design of the weir is such that it is physically impossible to top the dam with water. can not happen. |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote Tis normal... Attached File |
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Definitely bubbles. There were 2 or 3 spots where they came up. Do we have 2 or 3 suns in our solar system? Remind me how reflections work... View Quote View All Quotes View All Quotes |
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Oh Shit! I'm sure I missed a lot of the recent thread but did anyone notice this in one of the videos? Water appearantly pour INTO side of flume from espillway side??? http://i68.tinypic.com/ru1mzd.jpg View Quote No. Pipes to keep the spillway wet. Not sure why but not a leak. |
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not liking that. hopefully just voids from years of drought filing and adjusting - not actual flow through the rock strata. View Quote View All Quotes View All Quotes Quoted:
not liking that. hopefully just voids from years of drought filing and adjusting - not actual flow through the rock strata. how sure are we that's bubbles?.. |
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Looks more like a reflection of the sun to me. View Quote View All Quotes View All Quotes Quoted:
Looks more like a reflection of the sun to me. |
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It appears they are using every available second to lower the lake as much as possible in anticipation of the incoming storms. View Quote Not so much. They lack confidence in the remaining integrity of the main spillway, otherwise they would be draining the swamp at the rated capacity of 150k cfs. |
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Definitely bubbles. There were 2 or 3 spots where they came up. Do we have 2 or 3 suns in our solar system? Remind me how reflections work... View Quote I'm not saying it's not bubbles, but the surface of a large body of water like a lake isn't normally perfectly planar especially if there is any wind. This can cause more than one instance of reflection from a single point. Just go sit on the edge of the lake on a sunny day and the sun will reflect in your eyes from multiple places. It doesn't mean we have 2 suns. |
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What I'm saying is that the main spillway flow was reduced to minimize damage to it from erosion. At that time, I don't recall hearing anything about testing the espillway. When the erosion below and around the espillway looked like it would compromise or undercut it, they freaked out thinking failure was imminent and opened up the main spillway to take pressure off the espillway. That's when the Sheriff ordered the evacuation. Not damaging the infrastructure was a reference to the fear that the main spillway would be undercut all the way to the gates if they kept up the high flow rate. Hours after opening up the main spillway more, they discovered that erosion was not as rapid when the flow rate was higher. But their initial fear was always that increased flow would destroy the main spillway and possibly compromise the dam. If you'll recall, there was a lot of attention to the laydown area and road to the right of the main spillway. View Quote View All Quotes View All Quotes Quoted:
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The e-spillway was untested. Now it is tested and the issues can now be resolved. I fully believe the water over the e-spillway was intentional, for this exact purpose. That is why they kept the spillway output so low to begin with. Once they thought there was a problem they bumped up the spillway output and 4 hours later the water stopped flowing over the e-spillway. I don't think so. They bumped up the flow from the main spillway because of the threat of complete failure of the espillway, not because the testing was complete. They were trying to save the main spillway when they were reducing flow over it. The upside was that they discovered that the main spillway suffered less damage at the higher flow rate. I never said the testing was complete. Someone freaked out close to dark and they ramped up the spillway. Had they ramped up the spillway 4 hours earlier there never would have been a freak out. Even then they spillway has more capacity, so they never really believe the "catastrophic failure in 60 minutes" statement that they put out. The engineer that spoke that night said their main concern was not damaging the infrastructure, so letting it run over the e-spillway was intentional. The lies came from the "60 minutes until failure, water is eroded under the face of weir". What I'm saying is that the main spillway flow was reduced to minimize damage to it from erosion. At that time, I don't recall hearing anything about testing the espillway. When the erosion below and around the espillway looked like it would compromise or undercut it, they freaked out thinking failure was imminent and opened up the main spillway to take pressure off the espillway. That's when the Sheriff ordered the evacuation. Not damaging the infrastructure was a reference to the fear that the main spillway would be undercut all the way to the gates if they kept up the high flow rate. Hours after opening up the main spillway more, they discovered that erosion was not as rapid when the flow rate was higher. But their initial fear was always that increased flow would destroy the main spillway and possibly compromise the dam. If you'll recall, there was a lot of attention to the laydown area and road to the right of the main spillway. Yeah that is pretty much how I see it. However, parts of it don't add up. If the e-spillway is built on solid bedrock then wouldn't there be bedrock under at least part of the spillway? They never admitted to testing the e-spillway and I doubt they ever will, but that is what they did and it was intentional. When you have 130,000 cfs inflow and 35,000 cfs outflow, the lake gaining 9 feet in elevation every day, anyone who can do simple math could tell you the e-spillway was going to see water. Someone made the decision "the e-spillway is there, let's see what it can do". The engineer never said anything about compromising the dam. He said they wanted to continue to use the infrastructure this year. So it was all about money and saving some concrete in the spillway, which is what several of us were saying back in the initial pages of the thread. Why did DWR issue the "60 minutes to failure" warning. That is one piece that does not make any sense. They had more spillway capacity that they didn't use. The erosion is nothing close to what they said, under cutting the face of the weir. I think the sinkhole downhill from the parking lot end caused some panic as they weren't expecting it, but that isn't a 60 minutes to failure issue either. |
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It appears they are using every available second to lower the lake as much as possible in anticipation of the incoming storms. View Quote They have to. I still believe if water goes over the espill the lake will drain from erosion underneath. I believe that's what caused the evac as the erosion moved futher towards the weir. Massive amounts of material were removed. |
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I think its much higher. I found a document on weirs that says the discharge coefficient increases dramatically for high head situations. A 1700' weir with 20' of head can be upwards of 500,000 cfs. I posted the link back a few pages, not sure I can find it again. View Quote C=(2/3)2/3 (g) 1/2 Q=CLH3/2 I'm not going to figure out how to display powers... g=32.2 H =30 L=1700 Have at it... Edit: coincidentally 2ft of head over the 1700ft gives you 14845cfs |
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With that turban I'm not going to worry much about which hand he's using. He's likely one of the good guys. View Quote View All Quotes View All Quotes Quoted:
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At least he's using his right hand. Did they run out of gloves? And tongs? With that turban I'm not going to worry much about which hand he's using. He's likely one of the good guys. I'd appreciate gloves or tongs for handling the fries. |
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This past Sunday night, the forecasted snow level was 'down to 5,000 ft '. Has that changed? The thing that's not needed is a warming trend that will start melting the existing snow-pack early. That could be catastrophic. Not only is the Feather River drainage running at or over capacity, all the feeder drainages downstream will contribute to the flow. All the lowlands, all the way to the delta, stand a chance to see major flooding. View Quote View All Quotes View All Quotes Quoted:
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I came for the collapse. When should I check back? The thing that's not needed is a warming trend that will start melting the existing snow-pack early. That could be catastrophic. Not only is the Feather River drainage running at or over capacity, all the feeder drainages downstream will contribute to the flow. All the lowlands, all the way to the delta, stand a chance to see major flooding. Actually, from a "worst case scenario" POV for the inflow would be a night of relatively low snowline (5k feet is low) followed by a daytime rain above that level. The rain would wash the snow down with it and we'd see very high inflow very suddenly. |
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I don't get the lack of equipment and man power dedicated to fix this.
A few rock trucks, a single pumper and what looks to be maybe a CAT 336? Fuck it. You're talking about billions of dollars in possible damage. Line up a few D11's. Line up about 100+ dump trucks. Have every quarry in trucking distance ramp up production to 150%. Start dumping on whatever edge is the strongest that you can get trucks to, and start pushing. They've had 24 hours so far, they got what? Another 24 hours at best before rain comes? D11's move a serious amount of material. Fucking get to it skippy. Even if you can't find a few spare 11's sitting around. I know the state of California owns D8's and D9's. I know the military owns D7-D9's. Get to it. I know little contractors that have moved 300,000 yards of dirt in 48 hours with x4 D8's. They can do better. Riprap everything. |
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I'm not saying it's not bubbles, but the surface of a large body of water like a lake isn't normally perfectly planar especially if there is any wind. This can cause more than one instance of reflection from a single point. Just go sit on the edge of the lake on a sunny day and the sun will reflect in your eyes from multiple places. It doesn't mean we have 2 suns. View Quote View All Quotes View All Quotes Quoted:
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Definitely bubbles. There were 2 or 3 spots where they came up. Do we have 2 or 3 suns in our solar system? Remind me how reflections work... I'm not saying it's not bubbles, but the surface of a large body of water like a lake isn't normally perfectly planar especially if there is any wind. This can cause more than one instance of reflection from a single point. Just go sit on the edge of the lake on a sunny day and the sun will reflect in your eyes from multiple places. It doesn't mean we have 2 suns. I can make out the wind driven wave pattern, but the "bubbles" appear to generate their own ripples outward looking at the video. Also, the helicopter is moving along the weir, but the "reflections" stay in the same point indexed to the ground along the edge. A reflection should change position based on the viewpoint of the camera and angle to the sun, from what I've noticed flying in planes near sunrise/sunset. Just my 2 cents. |
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