Reply
 
Thread Tools Display Modes
  #1  
Old 06-06-2019, 07:12 AM
Orville mogul is offline
Guest
 
Join Date: Apr 2004
Location: Villa Bennius
Posts: 673

Is there a maximum mountain elevation?


I was hiking in my local mountain chain yesterday and got to wondering about what determines the height of mountains. Is there some sort of natural geological maximum elevation mountains can reach?

And along the same lines, during geological history, would there have been mountains that were higher than the Himalayas are now?
  #2  
Old 06-06-2019, 07:20 AM
Qadgop the Mercotan's Avatar
Qadgop the Mercotan is offline
zymolosely polydactile
Charter Member
 
Join Date: Apr 2000
Location: Slithering on the hull
Posts: 27,393
This site claims 10 km (about 33,000 feet) as the ceiling, and uses a lot of math to determine that number, but I don't know how good this analysis really is.

Last edited by Qadgop the Mercotan; 06-06-2019 at 07:21 AM.
  #3  
Old 06-06-2019, 07:27 AM
puzzlegal's Avatar
puzzlegal is online now
Member
 
Join Date: Jul 2014
Posts: 4,813
I can't find a reference now, but I've read that the central pangean mountains

https://en.m.wikipedia.org/wiki/Cent...gean_Mountains

Now represented by some very modest mountain ranges, like the Appalachians, were the highest the world has seen. (But have worn down over the ages.)
  #4  
Old 06-06-2019, 09:07 AM
DesertDog is offline
Charter Member
 
Join Date: Oct 2002
Location: Mesa, Ariz.
Posts: 5,782
@QtM If the site is correct, Mauna Kea is pushing the limit because it is 10,203 meters from base to peak, not just the part that got its head above water.
  #5  
Old 06-06-2019, 09:20 AM
Chronos's Avatar
Chronos is offline
Charter Member
Moderator
 
Join Date: Jan 2000
Location: The Land of Cleves
Posts: 85,111
It helps, though, that most of it is underwater. Stone doesn't float, but it's still at least somewhat buoyant.
  #6  
Old 06-06-2019, 10:10 AM
Omar Little's Avatar
Omar Little is offline
Guest
 
Join Date: Apr 2000
Location: Within
Posts: 13,200
If they get too high they could possibly flip over in the ocean? I know there was some concern in the past about Guam possibly flipping over, due to massive build up there.
  #7  
Old 06-06-2019, 10:51 AM
Qadgop the Mercotan's Avatar
Qadgop the Mercotan is offline
zymolosely polydactile
Charter Member
 
Join Date: Apr 2000
Location: Slithering on the hull
Posts: 27,393
Quote:
Originally Posted by Omar Little View Post
If they get too high they could possibly flip over in the ocean? I know there was some concern in the past about Guam possibly flipping over, due to massive build up there.
I have read that our politicians are closely monitoring that situation. I'd leave the matter in their capable hands.
  #8  
Old 06-06-2019, 11:27 AM
leahcim is offline
Member
 
Join Date: Dec 2010
Location: Boulder, CO
Posts: 3,673
My understanding is that some soft limits are determined by isostasy, and that if a mountain extends upwards, it has to have a "root" that extends downwards into the crust, and there is a limit to how deep that root can go before it melts at the bottom.

Mountains can still rise above that level if some process is actively pushing them up, but that puts a long-term soft limit.
  #9  
Old 06-06-2019, 11:41 AM
TriPolar is online now
Guest
 
Join Date: Oct 2007
Location: rhode island
Posts: 40,708
Quote:
Originally Posted by Omar Little View Post
If they get too high they could possibly flip over in the ocean? I know there was some concern in the past about Guam possibly flipping over, due to massive build up there.
I've heard something similar for the island of Tenerife. It is composed of three different undersea mountains fused together, and possibly some part of it could collapse into the sea. But I might have the wrong Canary island in mind. I would think that there's just a massive avalanche, not sure what you mean by 'flipping over'.
  #10  
Old 06-06-2019, 11:59 AM
kanicbird is online now
Guest
 
Join Date: May 1999
Posts: 19,631
In theory, if god made it with the correct materials when he blinked the universe into existence it could extend up into orbit, a natural space elevator.
  #11  
Old 06-06-2019, 12:02 PM
Riemann's Avatar
Riemann is offline
Guest
 
Join Date: Nov 2015
Location: Santa Fe, NM, USA
Posts: 7,648
Quote:
Originally Posted by kanicbird View Post
In theory, if god made it with the correct materials when he blinked the universe into existence it could extend up into orbit, a natural space elevator.
I'm quite confused. Are you trying to mock people who mock your religious beliefs by mocking religious beliefs yourself? Are you a metamocker?
  #12  
Old 06-06-2019, 01:02 PM
Chronos's Avatar
Chronos is offline
Charter Member
Moderator
 
Join Date: Jan 2000
Location: The Land of Cleves
Posts: 85,111
The Guam bit is a reference to a politician some years back who was worried about the island capsizing if it had too much weight on it. Islands don't actually work that way.
  #13  
Old 06-06-2019, 01:11 PM
Machine Elf is offline
Guest
 
Join Date: Feb 2007
Location: Challenger Deep
Posts: 12,291
Quote:
Originally Posted by Omar Little View Post
If they get too high they could possibly flip over in the ocean? I know there was some concern in the past about Guam possibly flipping over, due to massive build up there.
Not sure about Guam, but if this XKCD poster is accurate, than the ratio of Mauna Kea's height to width is such that it can't "fall over"; it's already lying down. I'd be surprised if other islands had height/width ratios that posed a risk of the entire island toppling over.

The actual Guam remark by Hank Johnson was this:

Quote:
Originally Posted by Hank Johnson
Yeah, my fear is that the whole island will become so overly populated that it will tip over and capsize.
His remark was preceded by a discussion of the length and width of the island (as a measure of land area), but no mention of altitude or local sea depth - and it was followed by remarks about enviromental degradation. He was not actually addressing the geological instability of the island; rather, it was a facetious commentary regarding a large influx of US military personnel, their dependents, and construction workers. However, because of his lack of any comedic cues while he was speaking, everyone took his remark at face value.

Last edited by Machine Elf; 06-06-2019 at 01:13 PM.
  #14  
Old 06-06-2019, 07:29 PM
Gray Ghost is offline
Guest
 
Join Date: Apr 2008
Posts: 4,387
Quote:
Originally Posted by TriPolar View Post
I've heard something similar for the island of Tenerife. It is composed of three different undersea mountains fused together, and possibly some part of it could collapse into the sea. But I might have the wrong Canary island in mind. I would think that there's just a massive avalanche, not sure what you mean by 'flipping over'.
La Palma is the one usually cited. In depth discussion about the mega tsunami possibility at this AGU blog post: https://blogs.agu.org/landslideblog/...thesis-part-1/

The author doesn't believe in the hypothesis, but nevertheless lays out the evidence for it pro and con.
  #15  
Old 06-06-2019, 09:42 PM
TriPolar is online now
Guest
 
Join Date: Oct 2007
Location: rhode island
Posts: 40,708
Quote:
Originally Posted by Gray Ghost View Post
La Palma is the one usually cited. In depth discussion about the mega tsunami possibility at this AGU blog post: https://blogs.agu.org/landslideblog/...thesis-part-1/

The author doesn't believe in the hypothesis, but nevertheless lays out the evidence for it pro and con.
Thanks. When I heard about this it sounded kind of hokey. It sounded like half the island would just sink into the ocean leaving the other half standing.
  #16  
Old 06-06-2019, 09:48 PM
borschevsky is online now
Guest
 
Join Date: Sep 2001
Location: Canada
Posts: 2,122
Feynman mentions this limit in passing at the 48 minute mark of this interview video. Any excuse to show people that video .
  #17  
Old 06-06-2019, 10:57 PM
Mnemnosyne is offline
Guest
 
Join Date: Dec 2009
Posts: 354
On a related note, I've always wondered why Earth seems to have such runty mountains; it's my understanding that many of the other rocky bodies of the solar system - Mars, some of the moons of Jupiter, and possibly Venus - have mountains that make ours look like molehills. I know that's true for Mars, which is smaller than Earth. I might be wrong on the premise, too, since the only ones I'm sure are huge mountains are on Mars - maybe wherever I heard that other planets/moons also have huge mountains was wrong?
  #18  
Old 06-07-2019, 12:15 AM
borschevsky is online now
Guest
 
Join Date: Sep 2001
Location: Canada
Posts: 2,122
Watch the video clip I posted .

The mountains are higher because those bodies are smaller than the earth. Lower gravity means that the rock can support a larger mountain before collapsing.
  #19  
Old 06-07-2019, 01:36 AM
The Stafford Cripps is offline
Guest
 
Join Date: Oct 2001
Posts: 1,352
Quote:
Originally Posted by Mnemnosyne View Post
On a related note, I've always wondered why Earth seems to have such runty mountains; it's my understanding that many of the other rocky bodies of the solar system - Mars, some of the moons of Jupiter, and possibly Venus - have mountains that make ours look like molehills.
I don't know how much of a difference it makes but they all have lower gravity than Earth. Erosion is different too: the moon has no wind or rain, Mars has less than we do, and AFAIK Venus doesn't have frost shattering.
  #20  
Old 06-07-2019, 08:10 AM
Telemark's Avatar
Telemark is offline
Charter Member
 
Join Date: Apr 2000
Location: Just outside of Titletown
Posts: 22,988
Gravity is the biggest factor. The strength of the materials doesn't change that much, but the forces on a more massive planet are much higher.

Last edited by Telemark; 06-07-2019 at 08:10 AM.
  #21  
Old 06-07-2019, 05:13 PM
glowacks is offline
Guest
 
Join Date: Aug 2008
Posts: 2,199
I was under the impression that the water cycle was the main reason mountains eroded. Even if it's constantly frozen, it at least is much faster in carrying down the highest parts of the mountain than just wind.
  #22  
Old 06-12-2019, 05:20 AM
Orville mogul is offline
Guest
 
Join Date: Apr 2004
Location: Villa Bennius
Posts: 673
thanks everyone. Very helpful explanations.

I was wondering whether the lack of oxygen at that elevation would have any impact on erosion of the rock? Oxidation being less and all that.... But of course the rock is covered by ice in most cases, so probably not in much contact with the air.

Another thing that just struck me is whether it means anything that the 'death zone' for humans coincides with the limit to mountain elevation. Perhaps as humans evolved there was no need for their bodies to survive on less oxygen than is available at 8,000 meters, since they couldn't go higher than that anyway?

Just a few idle thoughts...
  #23  
Old 06-12-2019, 07:29 AM
Machine Elf is offline
Guest
 
Join Date: Feb 2007
Location: Challenger Deep
Posts: 12,291
Quote:
Originally Posted by Orville mogul View Post
Another thing that just struck me is whether it means anything that the 'death zone' for humans coincides with the limit to mountain elevation. Perhaps as humans evolved there was no need for their bodies to survive on less oxygen than is available at 8,000 meters, since they couldn't go higher than that anyway?
The death zone boundary is a bit fuzzier than the name suggests:

https://en.wikipedia.org/wiki/Effect...tude_on_humans

As adaptable as human beings are, I think we evolved that adapatibility before we started exploring very high altitudes. At those sorts of altitudes, there's not much in the way of food (or anything else) to be had, so any kind of settlement requires a modern supply chain, something that wouldn't have existed thousands of years ago. FWIW, the highest permanent settlement is only at 16,700 feet. People currently living at high elevations do exhibit physiological adaptations, but it's unclear whether these are due to nature (i.e. evolution) or nurture (i.e. exposure to high elevation from the moment of conception).
  #24  
Old 06-12-2019, 07:43 AM
dtilque is online now
Charter Member
 
Join Date: Jan 2000
Location: My own private Nogero
Posts: 7,149
Quote:
Originally Posted by Machine Elf View Post
People currently living at high elevations do exhibit physiological adaptations, but it's unclear whether these are due to nature (i.e. evolution) or nurture (i.e. exposure to high elevation from the moment of conception).
Recent report says that Tibetans got one gene that adapts them to high altitudes from interbreeding with Denisovans.
__________________
“This world is a strange madhouse. Currently, every coachman and every waiter is debating whether relativity theory is correct. Belief in this matter depends on political party affiliation.”
-- Albert Einstein, 12 September 1920
  #25  
Old 06-12-2019, 08:39 AM
Telemark's Avatar
Telemark is offline
Charter Member
 
Join Date: Apr 2000
Location: Just outside of Titletown
Posts: 22,988
Quote:
Originally Posted by dtilque View Post
Recent report says that Tibetans got one gene that adapts them to high altitudes from interbreeding with Denisovans.
Someone brought this report up in a conversation over dinner last night. I wonder if there's any similar pattern in Peruvians with similar genetic adaptations.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:18 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@straightdope.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Copyright © 2019 STM Reader, LLC.

 
Copyright © 2017