Re: Continents and Islands?

In article <kpj1f217fhtahp8rpr09lcdkj1nabsk188@xxxxxxx>,
r norman <r_s_norman@xxxxxxxxxxxx> wrote:

On Sat, 26 Aug 2006 15:30:04 -0700, Timberwoof
<timberwoof.spam@xxxxxxxxxxxxxxx> wrote:

In article <ora1f2hgiqa2e27ghlnqv3o9fkhh3b7ekm@xxxxxxx>,
r norman <r_s_norman@xxxxxxxxxxxx> wrote:

On Sat, 26 Aug 2006 12:49:30 -0700, Timberwoof
<timberwoof.spam@xxxxxxxxxxxxxxx> wrote:

In article <1156593617.961709.83140@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
dgenglish@xxxxxxxxxxx wrote:

rev.goetz wrote:
r norman wrote:
On 25 Aug 2006 18:30:40 -0700, "rev.goetz" <jimgoetz316@xxxxxxxxx>
wrote:

What distinguishes a continent from an island?


The definition depends entirely on whether or not you live in
Australia.

However, if a continent is only a large island, then there are two
modern continents (without considering continental drift):
EuroAfroAsia and NorSouAmerica Then there are islands like
Antarctica
and Greenland.

If we consider continental drift, then how many continents are
drifting?

James Goetz

India is drifting (relative to the rest of Eurasia) Should we consider
that a separate continent? Should it have been considered a separate
continent 65 million years ago, before the two land masses collided?

I don't know whether it was that or just an island, but there was an
ocean (The Tethys Sea) between it and Asia. What's left of that sea
(ocean?) is in Tibet now.

So. What differentiates pond, lake, gulf, sea, and ocean?

Properly speaking a pond is not large or deep enough to have thermal
stratification whereas a lake is. That is my definition. Probably
nobody else in the world knows about it.

Hmmm. That sounds good, but on further thought I'm not sure about that.
I once read a description of the process by which a lake (or pond)
freezes over. It is, of course, the surface of the pond or lake that
cools the fastest, it being exposed to the cold air above. But the
surface water, now being heavier as a result of cooling off, flows to
the bottom. Thus the surface water is constantly being replaced with
warmer water from below. So not until the entire lake has reached
freezing temperature will the surface freeze. If a pond is not
stratified by temperature (are you sure about that?) it woudl freeze
differently.

Maybe I should put some water in a thick styrofoam container and put
that in a freezer, and watch what happens.

In temperate zones, at least, during the summer a lake has a warm
"epilimnion" layer above the cold "hypolimnion" separated by the
thermocline. During the winter, the water cools so that the coldest
water, down to 0C with ice on top lies above the "warmer" 4C water
which has a greater density. During the fall and spring during the
transitions, the system is very unstable and the waters mix. This
"overturn" is important in aerating the bottom water. Of course, many
ecologists describe this behavior for "ponds".

The ocean also has a thermocline, as do the largest and deepest lakes,
but they often do not show the same turnover.

The thermocline is usually about five or ten feet (2 to 4 meters)
deep, at least in my latitude. So a shallow pond isn't deep enough to
show that behavior. A "large pond" will, though.

Ah! Thank you for the explanation. :-)

Shouldn't a "continent" be that portion of a plate that is above
water?

Well, Indonesia is a plate of "continental" granite, but it's not as
tall as other continental plates, so only the mountains stick up above
the water.

Each plate must be a continent since these are what drift. Of
course "continental drift" might also be a total misnomer.

Continents do drift, but so does oceanic crust. The Pacific plate is
dragging a piece of North America -- just a sliver of the coast west of
the San Andreas fault -- northwards.

I was suggesting that all the plates are potential continents.

Well... there are plates that consist of ocean-floor basalt, so not
really.

And
just as we say that the traditional continents extend to the
continental shelf, all of Indonesia would qualify as a single
continent even though most of it is underwater.

Under my definition, Los Angeles and San Francisco would be excluded
from NAFTA.

That would suck. I just supervised the translation of a software product
into Spanish so we can sell it in Mexico.

--
Timberwoof <me at timberwoof dot com> http://www.timberwoof.com
Dear aunt, let's set so double the killer delete select all.

.

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