Re: Geology is a dangerous business


"jonathan" <maatschj@xxxxxxxxxxxxx> wrote in message
news:YFthf.20981$s92.14813@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> "George" <george@xxxxxxxxxxxxxxxxxxxxx> wrote in message
> news:Ljthf.576979$_o.207396@xxxxxxxxxxxx
>>
>> "jonathan" <maatschj@xxxxxxxxxxxxx> wrote in message
>> news:kSshf.20971$s92.14175@xxxxxxxxxxxxxxxxxxxxxxxxx
>> >
>> >> I suspect that when waves are breaking on the steps of citry hall,
>> >> they
>> >> will accuse us of not warning them soon enough.
>> >
>> >
>> > Incredible, just because the city is subsiding does not
>> > mean a conclusion of abandoning it is sound. It's
>> > completely irresponsible of this pseudo-scientist
>> > to say so. Unless he's done all the other work required
>> > to make such a dramatic decision.
>>
>> Johnny, it isn't going to magically rebound. There isn't a magic hand
>> out
>> there that is going to stop it from subsiding. It is subsiding, and
>> will
>> continue to subside. The equilibrium of the Mississippi delta has been
>> destabilized for over 100 years. New Orleans has been very low ground
>> since it was first settled. Just to get it back to it's former
>> elevation
>> of 100 years ago would cost more than the entire city is worth
>
>
> Show me the numbers that back up that statement. Isn't it you
> that constantly prattles on about facts? Your statement is
> not supported by any facts that I can see, and I doubt if
> it can be. So I must conclude you've divined those figures
> during some religious coma or drug induced hysteria.

If you would just put your bong down long enough, you might be able to see
that:

1) New Orleans covers 4,190 square miles and sits 90 miles north from the
mouth of the Mississippi River;
2) New Orleans city proper, a depression shaped like a crescent (thus the
nickname the Crescent City), is surrounded by water;
A) The Mississippi River at Canal Street has a width of 2200 feet, a
bankside depth of 30-60 feet and a mid-stream depth of 100-180 feet.
B) Lake Pontchartrain, connecting with the Gulf of Mexico, covers an
area of 621 square miles.
3) New Orleans is below sea level. Depending on what part of town you are
in, you can be from 5-10 feet below sea level. Generally speaking, the
closer you are to the river, the higher the elevation.
4) Hurricane protection-The Army Corps of Engineers verifies that the New
Orleans area has 325 miles of Congressionally authorized hurricane
protection including: Westbank (66 miles); New Orleans to Venice, La. (87
miles); LaRose, La to Golden Meadow, La. (40 miles); Grande Isle, La. (7
miles); Lake Pontchartrain and vicinity (125 miles).
5)Currently, 40% of all coastal wetlands in the United States are located
in Louisiana, and 80% of all wetland loss in our nation occurs in
Louisiana. From 1930-1990, the Mississippi River Delta lost more than 1,000
square miles of land.
6) Over the last 50 years, land loss rates had accelerated from 10 miles to
40 miles per year by the 1970s, with the current rate being approximately
25 square miles or 16,000 acres of wetlands a year. Coastal Louisiana is
poised to lose more than 10,000 acres per year for the foreseeable future.
7) New Orleans is sinking three feet per century--eight times faster than
the worldwide rate of only 0.4 feet per century. Currently, New Orleans, on
average, is eight feet below sea level--11 feet in some places.
8) "By the year 2100, the city of New Orleans may be extinct, submerged in
water. A future akin to the fabled sunken city of Atlantis? Yes, according
to Dr. Chip Groat, Director of the United States Geological Survey (USGS)
in Washington, D.C., "With the projected rate of subsidence (the natural
sinking of land), wetland loss, and sea level rise," he said, "New Orleans
will likely be on the verge of extinction by this time next century.""
http://www.sciencedaily.com/releases/2000/01/000121071306.htm

9) Many of the low-lying barrier islands that protect New Orleans and its
levees will disappear by 2050, leaving it much more vulnerable to
hurricanes than ever.

Johnny, in order to save New Orleans, you have to save the hundreds of
thousands of acres of wetlands and coastline that will surely be lost
otherwise, likely involve changing the course of the river, and make many
other changes to much of the river delta. Prior to Katrina, it was thought
that restoration might be possible (thought the cost would be
otherworldly). The erosion Katrina has caused has likely changed that
outlook permanently. In order to save just New Orleans and vicinity, there
would have to be a public works project of such a magnitude that it would
dwarf all others in comparison. The fact is, that it is not a question of
whether New Orleans can ultimately be saved; it cannot. The question is
how do we mitigate future losses due to the inevidable demise of this once
great city?

>
> and likely
>> involve moving substantial portions of it anyway. If they don't try
>> that
>> approach, the only alternative other than moving the city entirely would
>> be
>> to continue to built higher and higher flod walls. And that is simply
>> dumb. The best, most cost effective solution is to move the city. Will
>> that happen? I seriously doubt that it will. Politics makes strange
>> bedfellows, especially when the natural world is concerned.
>
>
> On this issue I defer to the Dutch, they seem to think building a levee
> that separates the lake from the ...sea... is the best choice. Then
> restoring
> the wetlands. Not cheap but a minor project next to moving an entire city
> that doesn't want to move.

The Netherlands has made great strides in wresting land from the sea.
Unfortunately for the Dutch, that can't last, and they well know it. After
Katrina smashed New Orleans, Amsterdam called for a major study of the
vulnerabilities of their dike system. It will be interesting, indeed, to
see what comes out of that study.

George


.

Relevant Pages

  • Re: Geology is a dangerous business
    ... New Orleans has been very low ground ... > 2) New Orleans city proper, a depression shaped like a crescent (thus the ... > area of 621 square miles. ... > 25 square miles or 16,000 acres of wetlands a year. ...
    (sci.geo.geology)
  • Re: Katrena predicted...
    ... > " It was a broiling August afternoon in New Orleans, Louisiana, the Big ... > But the next day the storm gathered steam and drew a bead on the city. ... > feet below in places-so the water poured in. ...
    (sci.med.transcription)
  • (OT) : Dredge Lake Pontchartrain -and- Raise the City of New Orleans
    ... DaviD - The actual plan to re-build the City of New Orleans ... Seven Feet; contoured more in the center and less on the sides. ... Lake Pontchartrain and the City of New Orleans ...
    (rec.radio.shortwave)
  • Re: (OT) : Dredge Lake Pontchartrain -and- Raise the City of New Orleans
    ... > DaviD - The actual plan to re-build the City of New Orleans ... > Seven Feet; contoured more in the center and less on the sides. ... on the bottom of Lake Pontchartrain in all that silt and mud? ...
    (rec.radio.shortwave)
  • Re: Katrena predicted...
    ... > " It was a broiling August afternoon in New Orleans, Louisiana, the Big ... > But the next day the storm gathered steam and drew a bead on the city. ... > feet below in places-so the water poured in. ...
    (sci.med.transcription)