Everest is the tallest mountain on Earth now, but I’m wondering: has it always been the tallest mountain, and will it always be the tallest? (using the same definition. Don’t go saying it isn’t the tallest once you change the definition.)
I mean, it was made by 2 plates crashing into each other, right? Before it was made, were there other mountains? How were they made, and where did they go? Did they erode down or did Everest overtake them?
Is Everest still growing? Are there other mountains “catching up” to it?
The Himalayas formed from the crumpling of two continental plates when India slammed into Eurasia. In this kind of collision, the result is upward crumpling. So the Himalayas is still growing while India is shrinking (stop cheering Pakistan!)
I don’t know of any similar observed case but a good bet might be the Mediterranean area where plates have been known to slam into each other and then separate. But there are no impressively high peaks there.
Tall mountains that form by the collision of oceanic and continental plates (like Andes) are almost always volcanic. They’re not very tall. Mt Aconcagua is an exception. Most volcanic mountains erode very quickly (in geologic terms.) But Aconcagua stopped being a volcano and became the victim of crumpling between the oceanic plate (Nazca) and the south American shield (continent) so it’s a hybrid volcanic arc - and result of crumpling (thrust faulting.)
Your other question, ancient tall mountains? The present is the key to the past, so there was likely a mountain similar to Everest (in type of formation if not height) that has either eroded down or was faulted down.
The entire Himalayas is growing as mentioned above but I don’t think any other peak is chasing Everest, except maybe K-2.
There were almost certainly mountains taller than Everest in the past, and there certainly will be in the future. Everest is still growing about 4 mm a year, but that won’t last forever.
All that being said, it’s also true that there were probably never mountains much bigger than Everest. Everest is thought to be about the largest that a mountain can get on Earth before the forces pulling it down necessarily overwhelm the uplifting forces. I think the current consensuses is that erosion due to glaciation is probably the limiting factor for a mountain’s height, though there are other factors as well. You might get a 10 km mountain on Earth, but you would never see something like Olympus Mons.
^
You mean isostacy and erosion? Those happen to all mountains but the crumpling and thrusting going on in the Himalayas (funny) are outpacing them. Exactly when will India stop pushing northwards into China will be the factor. One thing’s sure, it’ll be a lame excuse for declaring war on India.
Right, isostacy and various forms of erosion; it remains an active field of research what mechanisms are most important in limiting height.
Sure, the Himalaya are still rising, but as they get higher, the forces wearing them down also increase. Mountain ranges often reach a sort of dynamic equilibrium, where they remain at the same height even as the collision that forms them continues to occur. It’s not known exactly how much higher Everest will get, but it won’t be much higher. A 10 km mountain might be possible, but a 15 km mountain almost certainly isn’t.
It’s not like you’re comparing a 7-footer standing inside a ditch with a midget standing on a bar stool. One can argue that Everest should also be measured starting from the ocean floor. After all, what’s a little water? Why not measure everything relative to the point at the center of the Earth? Ultimately, you will still be asking “what’s the highest point on Earth” and that will be Everest.
But a better contender is when the Earth’s surface was just cooling, no ocean and atmosphere yet, steady bombardment by meteors. You must have had surface features tens to hundresd of miles relative to their highs and lows. But an atmosphere makes for a very smooth surface.
I’m sure that in various programs or articles I’ve watched or read about the history of Earth’s geology, they’ve casually mentioned mountains or mountain ranges that would have been taller than the Himalayas - we’re talking about Pangaea or the stages of its breakup - but I couldn’t dig up a cite if my life depended on it. I think we need a paleogeologist.
The stated elevation of Mt. Everest has changed considerably, just during my lifetime. Not because it is changing, but because the accuracy of means of measurement did not reach one-meter accuracy until just a few decades ago. In such a short period of time, there can be very little certainty about whether the peak (or any other competitors) is actually changing elevation. The current elevation (29,029 feet) was stated in 1955, independently confirmed in 1975, and has apparently remained the same for at least 60 years. The highest number I can get on Google Earth is 29,001.
