<p>You can find lot of steep mountains in our solar system, but Mountains which are outside of our Earth ain't steep enough to include in this list. If we are talking about steepest mountains (In terms of average and excluding overhanging cliffs) Trango Towers, The limestone Cliffs are some of the steepest mountains in our solar system. However quoting &quot;Tharsis Tholus is considered one of the steepest volcanoes, so are there any mountain/volcanoes&quot;, Tharsis Tholus' steepness is a tiny number when compared to the steepness of the Mt. Hakone, Japan. Also &quot;Boösaule Montes which is the tallest mountain in Io&quot; is also considerable steep but within Io ;) (It cannot give competition to mountains in the Karakoram Range). We cannot come to a conclusion since it will take ages to categorize and rank mountain's steepness unless we exclude the Himalayan range :)</p>

CC BY-SA 4.0
2021-12-23T04:01:48.000Z
potentially helpful in Space SE: [Just how steep are Pluto's tallest ice mountains?](https://space.stackexchange.com/q/57318/12102) The combination of low surface gravity and a strong material like water ice at very low temperature makes these a good candidate, and the images are really impressively steep for 3,500 tall mountains!
uhoh
CC BY-SA 4.0
2021-12-22T14:46:12.240Z
2021-12-22T14:46:12.240Z
Kavin Ishwaran
<p>Although Olympus Mons is the tallest mountain in the solar system, its slope is so gradual that the peak cannot be seen from the plain; it is hidden by the planet's curvature (flank slope = 5.2°). The answer to <a href="https://astronomy.stackexchange.com/a/47869/35206">this question</a> suggest Tharsis Tholus with average flank slope of 10° followed by Ceraunius Tholus with average flank slope 9°. Tharsis Tholus is considered one of the steepest volcanoes, so are there any mountain/volcanoes steeper than Tharsis Tholus?</p>
<p>I searched for a bit and found Boösaule Montes which is the tallest mountain in Io. <a href="http://www.gishbartimes.org/2009/01/boosaule-montes.html" rel="nofollow noreferrer">The mountain has an irregular morphology, with a relatively gentle slope throughout much of the mountain except for an abrupt scarp on the peak's southeastern margin. According to Schenk et al. 2001, this scarp has a height of approximately 15 km and a <strong>slope of 40°</strong></a>. But, I am not sure if this is to be considered as &quot;average flank slope&quot; as it is only steeper on one side.</p>

CC BY-SA 4.0
2021-12-22T11:06:14.097Z
I have collected 103 data to conclude the answer, I will let you know soon
Kavin Ishwaran
CC BY-SA 4.0
2021-12-22T14:43:07.760Z
How exactly do you define steepness? Where is the base of a mountain or the upper rim and start of base of a canyon? Do you consider maximum values? Average (if so what is averaged and how (median, mean,...)?
planetmaker
CC BY-SA 4.0
2021-12-22T14:48:06.907Z
@planetmaker its as simple as tangent in trig, (not going deep into it)
Kavin Ishwaran
CC BY-SA 4.0
2021-12-22T14:58:02.953Z
@Ishwaran Let me rephrase: Consider a mountain the shape of a perfect half-sphere. How steep is it? 90°? 45°? $<dy/dx> = \frac{2}{\pi} \int_0^\{pi/2} cos(x) dx$? Something else?
planetmaker
CC BY-SA 4.0
2021-12-22T15:10:47.850Z
if we want to make it simple, in your scenario its 45 degrees, radius = height,, Tangent functions gives us 45 degrees, If we do it in a calculus way, summation of tangential function where slope (x) approaches 0 and the average we get will also be 44.999998 I couldn't recognize the differential function you mentioned mathjax isnt working here
Kavin Ishwaran
CC BY-SA 4.0
2021-12-22T16:43:45.050Z
Are you asking about **all types** of volcanoes and mountains or just [shield volcanoes](https://en.wikipedia.org/wiki/Shield_volcano). As the answer you refer to states, Tharsis Tholus is a shield volcano. Shield volcanoes are named so, because they resemble an ancient Greek shield lying on the ground. [Stratovolcanoes](https://en.wikipedia.org/wiki/Stratovolcano) have much steeper slopes - see Mt Vesuvius, Mt Etna, Mt Fuji & the volcanoes in South & Central America.  For Mt Fuji, "Slope angles from the crater to a distance of 1.5–2 kilometres (0.93–1.24 mi) are 31°–35".
Fred
CC BY-SA 4.0
2021-12-23T03:52:17.863Z
`+1` related in Space SE: [How tall are Pluto's mountains? Are they the tallest ice features in the Solar System?](https://space.stackexchange.com/q/36310/12102) (spoiler: they're upwards of 3,500 meters!) Bodies with lower gravity are good places to look since it's one of the two main things that limits mountain height (the other is material strength I suppose). So now I've just asked  [Just how steep are Pluto's tallest ice mountains?](https://space.stackexchange.com/q/57318/12102)
uhoh
CC BY-SA 4.0
2021-12-23T03:59:42.133Z
there are really striking images there
uhoh
CC BY-SA 4.0
2021-12-23T04:06:44.857Z
@uhoh there are two ranges with high peaks, one is tenzing montes range and other one is hillary montes range, I will explain those in the question since it needs some work
Kavin Ishwaran
<geology>
Are there any mountains/volcanoes steeper than Tharsis Tholus?
Nilay Ghosh
# Are there any mountains/volcanoes steeper than Tharsis Tholus?

(Asked by: username_0 on 2021-12-22)

Although Olympus Mons is the tallest mountain in the solar system, its slope is so gradual that the peak cannot be seen from the plain; it is hidden by the planet's curvature (flank slope = 5.2°). The answer to [this question](https://astronomy.stackexchange.com/a/47869/35206) suggest Tharsis Tholus with average flank slope of 10° followed by Ceraunius Tholus with average flank slope 9°. Tharsis Tholus is considered one of the steepest volcanoes, so are there any mountain/volcanoes steeper than Tharsis Tholus?

I searched for a bit and found Boösaule Montes which is the tallest mountain in Io. [The mountain has an irregular morphology, with a relatively gentle slope throughout much of the mountain except for an abrupt scarp on the peak's southeastern margin. According to Schenk et al. 2001, this scarp has a height of approximately 15 km and a **slope of 40°**](http://www.gishbartimes.org/2009/01/boosaule-montes.html). But, I am not sure if this is to be considered as "average flank slope" as it is only steeper on one side.

**Tags:** geology
> **Comments:**
> **username_1**: I have collected 103 data to conclude the answer, I will let you know soon  
> **username_2**: How exactly do you define steepness? Where is the base of a mountain or the upper rim and start of base of a canyon? Do you consider maximum values? Average (if so what is averaged and how (median, mean,...)?  
> **username_1**: @planetmaker its as simple as tangent in trig, (not going deep into it)  
> **username_2**: @Ishwaran Let me rephrase: Consider a mountain the shape of a perfect half-sphere. How steep is it? 90°? 45°? $<dy/dx> = \frac{2}{\pi} \int_0^\{pi/2} cos(x) dx$? Something else?  
> **username_1**: if we want to make it simple, in your scenario its 45 degrees, radius = height,, Tangent functions gives us 45 degrees, If we do it in a calculus way, summation of tangential function where slope (x) approaches 0 and the average we get will also be 44.999998 I couldn't recognize the differential function you mentioned mathjax isnt working here  
> **username_3**: Are you asking about **all types** of volcanoes and mountains or just [shield volcanoes](https://en.wikipedia.org/wiki/Shield_volcano). As the answer you refer to states, Tharsis Tholus is a shield volcano. Shield volcanoes are named so, because they resemble an ancient Greek shield lying on the ground. [Stratovolcanoes](https://en.wikipedia.org/wiki/Stratovolcano) have much steeper slopes - see Mt Vesuvius, Mt Etna, Mt Fuji & the volcanoes in South & Central America.  For Mt Fuji, "Slope angles from the crater to a distance of 1.5–2 kilometres (0.93–1.24 mi) are 31°–35".  
> **username_4**: `+1` related in Space SE: [How tall are Pluto's mountains? Are they the tallest ice features in the Solar System?](https://space.stackexchange.com/q/36310/12102) (spoiler: they're upwards of 3,500 meters!) Bodies with lower gravity are good places to look since it's one of the two main things that limits mountain height (the other is material strength I suppose). So now I've just asked  [Just how steep are Pluto's tallest ice mountains?](https://space.stackexchange.com/q/57318/12102)  
> **username_4**: there are really striking images there  
> **username_1**: @uhoh there are two ranges with high peaks, one is tenzing montes range and other one is hillary montes range, I will explain those in the question since it needs some work  

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## 1 answers

### Answer by username_1 on 2021-12-22. Score: 1

You can find lot of steep mountains in our solar system, but Mountains which are outside of our Earth ain't steep enough to include in this list. If we are talking about steepest mountains (In terms of average and excluding overhanging cliffs) Trango Towers, The limestone Cliffs are some of the steepest mountains in our solar system. However quoting "Tharsis Tholus is considered one of the steepest volcanoes, so are there any mountain/volcanoes", Tharsis Tholus' steepness is a tiny number when compared to the steepness of the Mt. Hakone, Japan. Also "Boösaule Montes which is the tallest mountain in Io" is also considerable steep but within Io ;) (It cannot give competition to mountains in the Karakoram Range). We cannot come to a conclusion since it will take ages to categorize and rank mountain's steepness unless we exclude the Himalayan range :)

> **Comments:**
> **username_4**: potentially helpful in Space SE: [Just how steep are Pluto's tallest ice mountains?](https://space.stackexchange.com/q/57318/12102) The combination of low surface gravity and a strong material like water ice at very low temperature makes these a good candidate, and the images are really impressively steep for 3,500 tall mountains!  

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