-------- Original Message --------
Subject: RE: Fantasy Islands
Date: Tue, 2 Dec 2008 10:42:40 -0600
From: Hadden, Robert L ERDC-TEC-VA <[log in to unmask]>
To: Maps, Air Photo & Geospatial Systems Forum <[log in to unmask]>
CC: <[log in to unmask]>
References: <[log in to unmask]>
Dear Angie Cope:
The questions, as asked, are called "imponderables". That means there
is no real answer, because the questions ask undefined data to produce
defined results. No one can give a definite answer, only an estimate. Any
estimate can be challenged, since the authority used to create the estimate
is inherently imprecise.
Like trivia questions and bar bets, often these questions appear to
have a reasonable answer, but in reality, they don't. The answer moves about
as the parameters of the question changes.
The first question would be whether these questions should be
answered at high tide or at Low tide or average tide depth? Some islands
disappear at high tide. Others change shape, appear or disappear with each
tide flow. Also, do you want islands in rivers? In river deltas? Islands in
creeks? In lakes? Where do you draw the line? Because of so many questions
about the question, the question remains imponderable.
Since the sea floor of the South Pacific (and excuse me, but can
anyone define "South Pacific" with set points instead of in general areas?)
has not been detailed, any amount of sea water would only be estimated at
best.
In geology, the best example of an imponderable is the simple
question of what is the highest mountain? It sounds simple, but the
definitions change as the parameters of the question changes. Most people
would accept Mount Everest as the authoritative answer, as it is the highest
in height above sea level.
However, from base to summit, Mauna Kea in Hawaii is the highest,
although most of the mountain's height lies below sea level.
In addition, because of the earth's shape and bulge, the summit of
the inactive stratovolcano Chimborazo in Ecuador is the farthest in distance
from the center of the earth.
Good luck with your answers.
Lee
R. Lee Hadden
Geospatial Information Library (GIL)
Topographic Engineering Center
ATTN: CEERD-TO-I (Hadden)
7701 Telegraph Road
Alexandria, VA 22315-3864
(703) 428-9206
[log in to unmask]
"Curiosity is not a nice virtue- and it never leads to innocence." -Donna
Haraway
See some of my writings, both online and on paper, at my author page at:
http://www.librarything.com/author/haddenrobertlee
-----Original Message-----
------------------------------
Date: Wed, 26 Nov 2008 10:43:19 -0600
From: Angie Cope <>
Subject: Islands and south pacific - statistics needed
Hi Everyone,
I know I'm opening up a can of worms when asking (again) about how many
islands there are in the world. Back in 2004, I asked this same question and
we all agreed it's almost impossible to say because it depends on how you
define an island, etc. Here is what we came up with from that 2004
discussion:
The Alexandria Digital Gazetteer lists 70,088.
http://collections.alexandria.ucsb
<http://collections.alexandria.ucsb.edu/adl_gazetteer/metadata.html>
The inquiry in 2004 was from the Wall Street Journal and they
eventually quoted: "There are 500,000 to 600,000 islands in existence, says
Chris Mayda, professor of geography and geology at Eastern Michigan."
No one knows where Mayda got that figure from, but hey, it was
printed and now it's fact.
Moving on ...
Here are four questions I just got that I still don't know how to
easily answer:
(1) Total number of islands in the world
(2) Total number of islands in the South Pacific
(3) Volume of water in the South Pacific
(4) Sea area of the South Pacific
Any ideas?
Angie
|
