On Sun, 18 Sep 2005 23:00:09 GMT, Strabo
wrote:

In OT - NRA would argue, "Government policies don't kill
people,hurricanes kill people." on Sun, 18 Sep 2005 13:38:43
-0400, by Cliff, we read:

On Sun, 18 Sep 2005 08:37:38 -0500, "John Scheldroup"
wrote:

He'd have to dig another 80 feet before he reached bedrock consisting of compacted
clay, and silty sand.

Clay & sand would not be bedrock.
That 20,000 feet gets you to sandstone IIRC.

Its bedrock for the purposes of construction.

You could go down and open a sandstone mine at 20,000
feet I suppose.

Bedrock is bedrock. It is not loose sand, muck or winger BS.

BTW, New Orleans is sinking at an average of about
one foot every 30 years.

If that were true people would have been living under water
many years before the levees were constructed.

Ummm ..... That's why the built new levees as the city
expanded? And dewatered the swamp ... ?

Is this faith-based winger BS again?

There are two major factors that led to the basin in which
New Orleans sits. It was not settled underwater.

You seem confused again. Why?

People settled there to begin with because it was the
highest ground before reaching the inlet to the gulf
near the lake.

The lake was probably not very material.

There was no significant change in the New Orleans area
until the Mississippi River was constrained upriver by levees
beginning in the 1930s.

Sediment has been compacting & shrinking for millions of years.

In addition the Corps of Engineers rerouted tributaries
and dredged selectively.

Rather than flooding New Orleans every year. I see.

When the Mississippi was prevented from meandering, it
altered the way silt was deposited throughout the delta.

Gee ..... you don't suppose .... Where is it all now?

Prior to that the land adjoining the river was ordinarily
maintained through movement of the river with the deposition of
silt to offset erosion.

Good plan, eh? Bush's again?

BTW, How could it do that if it was always above water?

It was a building process. This banking
effect kept the ground level at New Orleans at 3 or 4 feet and
minimized flooding between the lake and the river.

Some large storm probably raised up the French Quarter.
After all, the rest is lower .....

The second reason is that the ground level between the lake and
river began to fall in the 1930s due to the weight of
construction and the depletion of groundwater.

"Weight of construction"?
How much per square foot does a house weigh compared to a
foot thick layer of muck?

The organics in the sediment decompose. The sediment compacts
with time too.
Dewatering does not help much.
--
Cliff