Geography query

[andymc]

Why do we have ice on mountains when they are nearer the sun yet below sea level (death valley etc) its at its hottest which is further away from the sun?
andymc

[whitechief]

The air pressure is lower at altitude.

[CaptainSlow]

and therefore retains less heat

[Ginetta G15 Girl]

The atmosphere is not directly heated by insolation but by heat re-radiated from the earth.

For an ICAO Standard Atmosphere there is an adiabatic lapse rate of 1.98 degrees C per 1000 ft (actually dry air cools faster than this and wet air slower).

Thus, in a Standard atmosphere, if the sea level temperature is 15 degrees C then the temperature at the top of Everest will be around -45C. Hence the snow.

[DangerousMike]

lower pressure = lower temp. sort of.

[aw51 121565]

Distance from the Sun of different points of the Earth is pretty insignificant - compare 10km (ballpark figure of difference between height of highest mountain to floor level in Death Valley) to 150 million km (again, ballpark figure). Figures might not be spot on but they represent the relative orders of magnitude.

As posted above, other effects are the important ones .

[10 Pence Short]

Put it really simply- the earth absorbs heat, as well as having its own heat source. Mountains are further away from the retained heat from the earth and the heat source underneath the crust.

[chimera40]

andymc said:

Why do we have ice on mountains when they are nearer the sun yet below sea level (death valley etc) its at its hottest which is further away from the sun?
andymc

This is you is'ent it.

[_Dan_]

Also, forgive me if I'm wrong, but isn't he centre of the earth a red hot pot of molten lava?

[chimera40]

_Dan_ said:

Also, forgive me if I'm wrong, but isn't he centre of the earth a red hot pot of molten lava?

Hmmm, no, it a big ball of iron and nickel about the size of the moon.

[zollburgers]

Air pressure as stated above. For example if you have 1 cubic metre of air at ground level that contains x amount of hotness (technical term), that same air at higher altitudes would still contain x amount of hotness but would be, say, 4 cubic metres. So the total amount of hotness in a cubic metre at altitude is now 4 times less.

[Eric Mc]

I never cease to be amazed by what people don't know.

Next time you're on your way by Sleezy Jet to Majorca, listen to the pilot when he gives you his little spiel about his crusing speed, altitude and outside air temperature.

Edited by Eric Mc on Saturday 23 January 23:45

[_Dan_]

chimera40 said:

_Dan_ said:

Also, forgive me if I'm wrong, but isn't he centre of the earth a red hot pot of molten lava?

Hmmm, no, it a big ball of iron and nickel about the size of the moon.

I was just guessing as a result of some tacky late 70's movies I've seen (Journey to the Centre of the Earth was it?), but some people with bigger brains than mine beg to differ....

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed...

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC58687/

....I know nothing though, only what I google!!

[jerwatt]

chimera40 said:

_Dan_ said:

Also, forgive me if I'm wrong, but isn't he centre of the earth a red hot pot of molten lava?

Hmmm, no, it a big ball of iron and nickel about the size of the moon.

Depending on how you break up the earth then it is a solid lump of iron and nickel (inner core), then the same but it can move around a bit (outer core), then the mantle (generally a mixture of stuff) which isn't actually molten, but can move around a bit and is very hot. You only get melting in certain conditions, such as an oceanic spreading centre (where the crust is effectively 0 thickness) - along the middle of the Atlantic, subduction zones (where volatiles such as CO2 and H2O are driven off the subducting plate and thus change the composition, causing it to have a lower melting point)- the Andes - and mantle plumes (although these are debated - effectively a place of exceptional heat) - Hawaii.

[cazzer]

Pffth...its molten lava.
I've seen that film where it stopped spinnin and they had to start it again.
With the heroic survive in molten lava machine.....

And Hollywood wouldn't lie to me.