# Hypothetical: A mountain reaches space **URL:** \ **Category:** Factual Questions\ **Created:** [December 15, 2012, 7:13pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125 "2012-12-15T19:13:30Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [December 17, 2012, 3:04am UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/21 "2012-12-17T03:04:03Z")
The Himalayas are still rising. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [December 17, 2012, 3:11am UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/22 "2012-12-17T03:11:43Z")
And the Hawaiian islands are 36k feet from the ocean floor to the top of Mauna Kea-not sure how much a difference shield volcanoes (vs. uplifted peaks like the Himalayas) make vis a vis pressure on the crust. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [December 17, 2012, 3:33am UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/23 "2012-12-17T03:33:53Z")
> [@al27052](#): > > I’ve read that the reason the Earth is so much colder now than during the time of the dinosaurs is because the Himalayas force the Jet Stream farther southward. The Jet Stream keeps the air north of it much colder. This creates a general cooling effect in the northern hemisphere, which in turn cools the whole planet. How does that happen? It makes no sense the way you put it; if the jet stream brings colder air south, it must also bring warmer air north, which is exactly what we observe to happen during Arctic air outbreaks - the Arctic warms at the expense of the U.S., Europe or wherever (the prevalence of such outbreaks in recent winters is due to Arctic warming due to ice loss causing a [weaker jet stream](http://www.news.cornell.edu/stories/June12/arcticWildcard.html), the strength of which depends on temperature gradients and location on average global/hemispheric temperature, not the other way around). That said, the Himalayas do in fact have something to do with the current cooler climate (besides a direct effect, if small on a global scale, from the high altitude), but because the rate of chemical weathering has increased greatly, [lowering levels of carbon dioxide in the air](http://www2.cnrs.fr/en/1038.htm) (combined with the collision of the Indian plate, which was previously subducting carbonate-rich seafloor, which was then released as CO2 in volcanoes until India reached Asia, leading to a peak in global temperature around that time; see [this PDF](http://www.columbia.edu/~jeh1/mailings/2011/20110118_MilankovicPaper.pdf), particularly pages 2 and 3). ---
**Author:** ![al27052](https://avatars.discourse-cdn.com/v4/letter/a/41988e/32.png) [@al27052](https://boards.straightdope.com/u/al27052)\ **Post date:** [December 17, 2012, 3:44pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/24 "2012-12-17T15:44:17Z")
> [@Michael63129](#): > > How does that happen? It makes no sense the way you put it; if the jet stream brings colder air south, it must also bring warmer air north, which is exactly what we observe to happen during Arctic air outbreaks - the Arctic warms at the expense of the U.S., Europe or wherever (the prevalence of such outbreaks in recent winters is due to Arctic warming due to ice loss causing a [weaker jet stream](http://www.news.cornell.edu/stories/June12/arcticWildcard.html), the strength of which depends on temperature gradients and location on average global/hemispheric temperature, not the other way around). > > . Guess who knows dick about climatology? yeah, me. ROFL But my assumption might be that the cold arctic air would just stay where it is, and the rest of the globe (except for, of course, the Antarctic, which has its own jet stream) would simply stay warmer. Perhaps there’d be no real difference in total global temperature, but the extreme cold would always stay in the Arctic. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [December 17, 2012, 4:14pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/25 "2012-12-17T16:14:02Z")
Any aggregation of matter in rotation, rotates around its center of mass. If the body is asymmetrical, the ceter of mass may not be at what you would logically think of as the “center”. However, the earth is 8,000 miles in diameter. A mountain (a cone) 100km (60 miles) tall, and let’s say 400 miles across, would still be a less-than-1% aberation in the distribution. Also, IIRC, the core is mostly iron, about density of 6, while crust rock is typically about a density of 3 (water=1). This makes it even less of an abberation. The core is molten iron, the mantle is pretty much liquid under the crust - a lump too big will sag and/or sink like a bunch of metal ball bearings on jello. Over millennia it will flow like jello too until it is light eough to be supported. Everest, IIRC, is about 5-1/2 miles tall and supported by the “floating” crust layer of India being pushed under the Himilayas) Obviously, any mountain will obstruct some air flow and create interesting weather conditions. One single mountain will probably not do much - the “big Island” in Hawaii does not appear to do much to the local weather. A range blocks flow, and also creates rain forest on the upwind side and deserts and chinooks on the downwind side. An east-west range can block some other interesting weather patterns (the Alps?) The higher the mountains, then bigger the effect. One side of the Himilayas in tropical India, the other side is Gobi, Mongolia and frozen steppes. The net result of any obstruction in weather flow is complex. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [December 17, 2012, 4:28pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/26 "2012-12-17T16:28:30Z")
> [@robert\_columbia](#): > > 1. The materials the mountain is made of would matter in terms of weight. You could make the mountain out of less dense minerals and whatnot, say a mountain made of talc. Yes, a mountain made of talc would be lighter, but also much weaker. The base of a mountain has to be strong enough to support the weight of the material above the mountain, otherwise the mountain will crush itself. Mountains occur because there are forces that push material higher, and those forces have to counteract the forces that push the material lower. Mountains erode due to wind and water and glaciation, they sink into the crust, parts slide off. So there is a constant tension between mountain building and erosion. When erosive forces are stronger the mountain/mountain range gets smaller, when mountain building forces are stronger then the mountain gets larger. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [December 17, 2012, 7:53pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/27 "2012-12-17T19:53:22Z")
> [@md2000](#): > > Obviously, any mountain will obstruct some air flow and create interesting weather conditions. One single mountain will probably not do much - the “big Island” in Hawaii does not appear to do much to the local weather. A range blocks flow, and also creates rain forest on the upwind side and deserts and chinooks on the downwind side. An east-west range can block some other interesting weather patterns (the Alps?) The higher the mountains, then bigger the effect. One side of the Himilayas in tropical India, the other side is Gobi, Mongolia and frozen steppes. > > The net result of any obstruction in weather flow is complex. For another example, the Rocky Mountains determine the climate in Europe, among other areas: > [@](#): > > Seasonal storage and release accounts for half the winter temperature difference across the North Atlantic Ocean. But the 500 pound gorilla in how regional climates are determined around the Atlantic turned out to be the Rocky Mountains. Because of the need to conserve angular momentum, as air flows from the west across the mountains it is forced to first turn south and then to turn north further downstream. As such the mountains force cold air south into eastern North America and warm air north into western Europe. This waviness in the flow is responsible for the other half of the temperature difference across the North Atlantic Ocean. (taken from [here](http://www.ldeo.columbia.edu/res/div/ocp/gs/), which explains that the Gulf Stream has relatively little influence on Europe’s climate, which is mostly due to to the factors mentioned above and the prevailing (west-east) wind direction; this is the same reason the Pacific NW is much warmer than New England) ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [December 17, 2012, 7:54pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/28 "2012-12-17T19:54:27Z")
> [@Lemur866](#): > > …So there is a constant tension between mountain building and erosion. When erosive forces are stronger the mountain/mountain range gets smaller, when mountain building forces are stronger then the mountain gets larger. This is what I was thinking as well. Wouldn’t a mountain encounter increased erosion the higher it got (through wind, glaciation and avalanches)? Perhaps the upper limit for mountain height (on Earth) is determined by erosion? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 17, 2012, 8:27pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/29 "2012-12-17T20:27:28Z")
> [@](#): > > Quoth **Dahnlor** : > > The limit is around 30,000 ft - which, ironically, is the height of the world’s tallest mountains, i.e. the Himalayas. Sorry, no cite. What’s ironic about that? That’s exactly what one should expect, that the highest mountains on a planet should be about as high as it’s possible for mountains to get on that planet. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [December 17, 2012, 8:41pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/30 "2012-12-17T20:41:38Z")
> [@snowthx](#): > > This is what I was thinking as well. Wouldn’t a mountain encounter increased erosion the higher it got (through wind, glaciation and avalanches)? Perhaps the upper limit for mountain height (on Earth) is determined by erosion? The peaks of very high mountains get little precipitation because they are [above most weather](http://www.wunderground.com/blog/weatherhistorian/article.html?entrynum=27); even the lower elevations of Everest aren’t that wet: > [@](#): > > The actual summit of Mt. Everest probably receives very little precipitation being above the usual condensation/precipitable elevation, and what little that does fall (as snow of course) is usually blown clear of the summit. The Base Camp for climbing expeditions is located at an elevation of 17,600’/5400m and receives an average annual precipitation of 18” (450mm). Compare that to: > [@](#): > > The area to the southeast of Mt. Everest probably receives as much as 100” (2500mm) of precipitation in favored valleys and ridges below 10,000’ (3,000m). Since snow doesn’t readily accumulate due to the winds, glaciers don’t form to the extent that they can on lower elevations, so wind erosion would be the dominant factor for erosion at high altitudes, but I don’t think wind by itself is very effective unless there is dust or sand in it (and as previously mentioned, the Himalayas are still rising). ---
**Author:** ![panaccione](https://avatars.discourse-cdn.com/v4/letter/p/94ad74/32.png) [@panaccione](https://boards.straightdope.com/u/panaccione)\ **Post date:** [December 17, 2012, 10:13pm UTC](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125/31 "2012-12-17T22:13:12Z")
VSauce asks a similar question. How high can we build? [http://www.youtube.com/watch?v=GJ4Qp2xeRds](http://www.youtube.com/watch?v=GJ4Qp2xeRds) [Previous page](https://boards.straightdope.com/t/hypothetical-a-mountain-reaches-space/644125.md?page=1)