12
$\begingroup$

Although I basically understand, that how the Himalayas formed, it has always confused me how did the vast high Tibetian Plateau came into existence behind it? And what would be its future, is it expected to remain as such for a long time?

$\endgroup$
6
  • $\begingroup$ I am unsure about the tags, please add them .. $\endgroup$
    – Sawarnik
    Apr 25, 2014 at 17:48
  • $\begingroup$ Appears that there might not be a single reason, but many reasons depending on where in the plateau you are looking at; for example, http://geology.gsapubs.org/content/41/4/439.abstract $\endgroup$
    – blunders
    Apr 26, 2014 at 1:56
  • $\begingroup$ There's the handwave-y version that says "rates of orogenic growth and rates of erosion eventually balance, because higher things are exposed to more erosion", plus simple issues of rock strength. However, I'm a volcanologist not a structural geologist; nonetheless if you'd like me to expand on this let me know and I'll type something proper up. $\endgroup$
    – kaberett
    Apr 29, 2014 at 16:57
  • $\begingroup$ @kaberett Ok :) $\endgroup$
    – Sawarnik
    Apr 29, 2014 at 17:26
  • $\begingroup$ I can't recall if crustal delamination is applicable to the whole plateau or not. $\endgroup$
    – Siv
    Apr 30, 2014 at 22:16

1 Answer 1

11
$\begingroup$

Per yesterday's What-If,

If you make a building too big, the top part is heavy and it squishes the bottom part.

In the context of Tibet, what this means is that rock has a yield strength: pile it up high enough and it will break (via earthquakes); and if you make a big enough pile, especially of continental material, then the concentrations of radiogenic isotopes will be high enough to significantly raise the temperature - and lower the strength - of the rock in question.

In the case of Tibet and the Himalaya, height increase is due to north-south shortening as the Indian plate impacts the Eurasian plate, i.e. the Tibetan plateau initially formed via exactly the same process as the Himalaya. In order to get an approximately stable height, this increase has to be balanced by decrease. The principle processes causing decrease in height in Tibet are:

That the Tibetan plateau is of such uniform height corresponds neatly to calculations suggesting that this is the maximum possible height for such features if they are of typical crustal composition.

$\endgroup$
1
  • $\begingroup$ Neat. Especially the last paragraph :-) $\endgroup$ May 4, 2014 at 11:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.