Talk:Lake Peigneur/Archive 1

Latest comment: 6 years ago by Heduanna in topic UTM vs Transverse Mercator
Archive 1

Barges

Quote: "by greatly increasing the depth of the lake from three feet to 1,300 feet" Can this be correct? A three-foot-deep lake had 11 barges on it???? Chesspieceface 05:54, 2 June 2006 (UTC)

The links indicate that the barges were all in the canal and sucked into the lake when the canal's flow reversed. 216.169.166.235 14:30, 2 June 2006 (UTC)

HA...if only it would happen in the LIS too!!

Is there some pictures to show for this page? Thomas1917 09:07, 14 October 2005 (UTC)
I know that there's a good deal of actual footage of the disaster, as I've seen it, but I don't know where or how we could get access to it, or some stills from it, for this article. siafu 15:22, 14 October 2005 (UTC)
The DamnedInteresting link has a B/W picture of barges, but I can't tell if they are being sucked in or if they have popped back up. Truly a fascinating event! --Mdwyer 04:31, 29 March 2006 (UTC)

Physics

According to the formula sqrt (2gh) there is enough potential energy to accelerate the water flow to 320 km/hr given a 1300 foot elevation drop. Using google calculator I determined that a 2 sq mile lake (1300 acres) 11 feet deep could drain through a 50 square meter hole (8m diameter) in three hours time. A person tipping over the rim into that rate of flow would be pressurized to 40 atmospheres in about 15 seconds, assuming a constant diameter hole. Has anyone ever worked out the physics of this much water heading south this fast? From the size of the objects unrecovered, the surface orifice must have been much larger.

Map/Data errors

Texaco claimed that the mine shafts were not accurately mapped. Probably true, since some shafts in this mine were over 100 years old. It's likely that the penetrated shaft was much younger, and better charted. Does anyone know where to get references to the age of the penetrated shaft? Does the drilling permit describe where the well was drilled? RPellessier | Talk 16:32, 18 June 2006 (UTC)

Video

History channel had a program on this lake. The video is amazing. youtube video of history channel on lake Peigneur -Ravedave 04:27, 28 July 2006 (UTC)

It was included in the Engineering Disasters series of Modern Marvels (I remember watching it on TV late at night). Does youtube keep their video files up indefinitely? If so, we should put a direct link on the page-- nothing tells the story like the footage. siafu 04:38, 28 July 2006 (UTC)

The only problem is the copyright status of the video. Is it legal to link to it? --Skatingrox 02:29, 31 July 2006 (UTC)

-- I just added the link, and now read your comment. Surely it's fine to link to external sites? Any copyright issue is a YouTube issue surely??

Something to note: When water hits salt, the salt dissolves. Hitting the mine shaft is not necessary to create a disaster like this. Drilling into the salt dome itself is enough to start the disaster. At the time of the disaster there was a debate in the drilling community about what would happen should some one drill into a salt dome. This settled the arguement.

I'm not sure what arguement was settled. Salt domes are drilled into all the time. This is one of the signs of where oil deposits are located. I know b/c I've been involved in such projects. Their are certain precautions that have to be taken. Different fluids can be used in order to minimize the dilution of the salt before the well is cemented.


Salt domes, yes. This was a salt mine, that had excavated 100 foot wide and tall caverns underground. That salt had been replaced by air. There's normally not air in salt domes, but yes in operating salt mines. Xj14y 08:40, 13 January 2007 (UTC)


And most of the times, when drilling into salt domes, this is done from land, not from water... A (relatively) dry well would not cause the dissolution of the salt in such a catastrophic way. — Preceding unsigned comment added by 158.64.72.230 (talk) 09:24, 22 February 2013 (UTC)

Ecosystem and geography changes

Does anyone know if any significant surveys of changes to the lake's ecosystem have been made? For that matter, the lake is incredibly deep - but is that because the entire floor of the lake was ripped away, or because the depth of the salt mine is included? It would be very useful to have a geological survey of the lakebed. Captainktainer * Talk 12:12, 16 August 2006 (UTC)

The mine itself obviously collapsed as water dissolved salt (although [diagram] seems to imply only part of the mine collapsed) and the mud eventually filled any opening left, so the depth of the lake should be where it's new floor stands . Which leads me to notice there is no aftermath section here. I would expect the lake's new steep slope to cause occasional landslides and reduce it's depth, the lake to gradually turn back to freshwater, and collapses in the mine to cause collappses on the surface.--Musaran (talk) 12:12, 24 September 2009 (UTC)
Maybe we should add this explanation (collapse of mine) why the lake got so much deeper to the main page? Also, a 164 feet waterfall rushing into a (formerly) 3 feet deep lake sounds somewhat weird (without any additional explanation, such as floor collapsing under lake) — Preceding unsigned comment added by 158.64.72.230 (talk) 09:28, 22 February 2013 (UTC)

Accuracy of article

As I read the article now, (and I grew up not far from there, maybe 7-8 miles) it is incorrect, as it says:

"The lake then proceeded to drain into the hole, with the salt underneath absorbing water nearly as fast as it poured in, resulting in the draining of the lake into the salt mine."

What was punctured was an enormous cavern under that lake where salt had been removed over the years. The salt did not act as a sponge and suck up the whole lake and half the Delcambre Canal. There isn't a sweet underground chamber with tons of little white bits of table salt in it. It's got to be ground in some cases, and in other cases, water is used to erode the rock purposely, then the water is removed during processing to make it ready for consumption. The ground up rock that we put on our food and dissolve in water does not absorb water.

I'm going to change that wording, as I think it is misleading. There are two types of salt mining, and both involve rocks. Unfortunately, I can't figure out which one this was, without making an assumption. More research needed. Xj14y 06:58, 13 January 2007 (UTC)

The occupant of the small boat claims, in the video, that he ran it ashore rather than walking to the former shoreline through the mud. VERIFICATE AND REVISE MAIN ARTICLE. 68.47.175.117 17:01, 23 January 2007 (UTC)

Irrelevant etymology

Of all the remarkable things about this lake, the meaning of the word "peigneur" is not one of them. No one will come to this article to brush up on their French vocabulary. So what's that doing as the first thing in the article? I'm of a mind to remove it completely if no one finds a more appropriate way to blend it into the article. --Kbh3rdtalk 02:32, 23 June 2007 (UTC)

I vote for leaving the etymology. LMB 21:00, 3 October 2007 (UTC)

It seems most articles about places here cover the meaning of the name.Ttenchantr (talk) 20:30, 24 November 2007 (UTC)

My edits

Please review my recent edits for accuracy or problems, especially if anyone has local knowledge. I removed or commented out several uncited claims and added data from epa.gov and some of the external links. Here are the two differences:

I removed the deepest and salt claims after googling did not find any current sources for either, the best was EPA's 300 foot estimate. FWIW I did some BOE calculation (original research) using EPA figures and estimated that the lake would refill with freshwater every 3 to 10 years - see html comments in the article. -Wikianon 19:16, 5 October 2007 (UTC)

Suggested Reading

Martinez, Joseph. "Salt Domes." American Scientist 79.5 (1991): 420-431. Print. Stable URL: http://www.jstor.org/stable/29774476

I came across this article and felt that it would be a nice addition to the information regarding this accident and engineering failure. The article is written by Joseph Martinez, a geologist who flew over the site a few day after the draining of the lake. In it he recounts the chain of events and walks the reader through the geology of salt domes, their formation and aspects that contributed to this engingeering disaster occurring in the fashion that it did. Drpudding (talk) 07:39, 10 February 2012 (UTC)

Date of disaster

Does anyone have a date? Alpheus (talk) 00:47, 10 December 2008 (UTC)

Depth of the freshwater lake

There are some comments in the "Disaster" section, which I'm copying here and adding to:

COMMENT 1

commented out this uncited claim derived from unqualified hearsay, no reliable source found for lake depths apart from EPA's 300 foot estimate: the deepest lake in Louisiana

COMMENT 2

note no RS found for current salinity, and freshwater input flow of 10 cu ft/s (0.28 m3/s) would have filled lake 3 (if average depth 10 foot) to 9 (if average depth 3 foot) times over since 1980

MY COMMENTS

1. The 10-foot claim needs a "citation needed". (I'm kind of new to that and don't know how to do that offhand.. my apologies for being a little sloppy and just making a note here for now.)

2. I don't think it matters what the freshwater inflow to the lake is. I think saltwater is heavier than freshwater, which would mean freshwater flowing in would flow out the canal without mixing with the deeper saltwater.

3. Do any geologists here know whether the salinity of the lake has been measured over time? Or whether the salt would slowly dissolve, and affect the ecosystem as much in the long term as the influx of saltwater did?

Krobin (talk) 06:54, 23 June 2011 (UTC)krobin

UTM vs Transverse Mercator

I found another source for this claim: https://www.cntraveler.com/stories/2016-07-11/how-louisianas-lake-peigneur-became-200-feet-deep-in-an-instant, though I'm not sure that qualifies as a citation.

In any event, the statement is somewhere between vague & inaccurate: Transverse Mercator is more of a category of projections, rather than being a projection itself, of which UTM is the most common implementation. (I'm a survey technologist, btw, but cf https://en.m.wikipedia.org/wiki/Transverse_Mercator_projection.). Maybe the confusion is between UTM & State Plane coordinates? Many State Planes are based on UTM, which would make them forms of Transverse Mercator, but it looks like Louisiana's State Plane is based on Lambert Conformal Conic. Heduanna (talk) 19:07, 29 October 2017 (UTC)