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How much height of a mountain or any topographic high, decreases for a million year averagely? What is the range? (min / max)

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    $\begingroup$ This is very broad, and it will depend on the climate. Can you narrow it down or explain better why you need these figures for? In this question: earthscience.stackexchange.com/q/13838/11908 I show some data related with glaciar erosion and you can see the range is quite wide. If you consider topographic features not covered by glaciers the range would be even wider. In a desert it can be very very small (a few milimiters), under an ice stream it can be huge (tens of kilometers or more). $\endgroup$ – Camilo Rada Mar 29 at 22:53
  • $\begingroup$ I want to guess the denudation amount of a 18 ma aged, stratovolcano with very well conical morphology placed on the 40 north lattitude. $\endgroup$ – Muharrem Yavuz Mar 30 at 8:04
  • $\begingroup$ Today the top is flattened, so it hasn't got an apex of the cone. $\endgroup$ – Muharrem Yavuz Mar 30 at 11:00
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    $\begingroup$ This will also depend a lot on what the mountain is made of. $\endgroup$ – John Mar 30 at 13:52
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    $\begingroup$ That denudation rate will very much depend on the location, tectonic setting and uplift rated and as @John said: the type of rock. A global typical value won't be of any help because the variability is huge. I think you would be better off looking for local geology studies of uplift rates, rock formations and ages. $\endgroup$ – Camilo Rada Mar 30 at 15:14
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This may not answer your question, but it indicates that erosion is extreme at high altitudes.

More than 60 percent of the sediment delivered to the world's oceans in the prehuman world originated from erosion in mountainous areas with elevations greater than 3 km above sea level.
Muddy Waters - More sediment is entering rivers, but less makes its way to the sea - Sid Perkins

Only about 1% of Earth's area is above 3 km.

enter image description here
(Fig. 2.4 of Deep-Sea Biology: A Natural History of Organisms at the Deep-Sea Floor) (via DavePhD)

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Although erosion rates vary widely depending on the location, tectonic setting, climatic history, fluvial incision, human disturbance, and other factors, there is a paper available online that illustrates and discusses the global variation in erosion rates as measured using cosmogenic nuclides. It is:

Portenga, E.W. and Bierman, P.R., 2011. Understanding Earth’s eroding surface with 10 Be. GSA today, 21(8), pp.4-10. https://www.geosociety.org/gsatoday/archive/21/8/article/i1052-5173-21-8-4.htm https://www.geosociety.org/gsatoday/archive/21/8/pdf/i1052-5173-21-8-4.pdf https://www.geosociety.org/datarepository/2011/2011216.pdf

In addition, An introduction to erosion rates and the processes that control erosion rates in mountains is the book: Burbank, D.W. and Anderson, R.S., 2009. Tectonic geomorphology. John Wiley & Sons.

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  • $\begingroup$ Interesting work. It would be great if you could summarize the finding of that paper? $\endgroup$ – Camilo Rada Apr 13 at 2:47

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