How big was Ancalagon?

[Nerwen]

Well, I stand corrected. However, I still think the reference is to the actual mountains, not just some buildings on them. I doubt that whole section is meant to bear analysis in terms of realistic physics.

[Ibrîniðilpathânezel]

On the other hand, there is some precedent for Tolkien's fiery critters breaking mountains when they fall and die. The Balrog of Moria "fell from that high place and broke the mountain-side where he smote it in his ruin." Not quite as spectacular as Ancalagon breaking the peaks of Thangorodrim, but the Balrog was smaller, and I doubt that Tolkien ever meant that the dragon took out the mountains (ala the Bakshi interpretation of the end of the Balrog). There is also a possibility that the peaks of the reference are not those of a naturally occurring mountain range, but rather something that Morgoth deliberately fashioned to look more menacing, like spires of rock much closer together than, say, the peaks of the Himilayas.

Then again, maybe when these fire-critters fall and die, they explode in a nuclear fashion and flatten the landscape. Perhaps the Yellowstone caldera isn't a leftover from an old volcano, after all....

[narfforc]

I do not think we can compare The Towers of Thangorodrim to any mountain or range of which we know. What we do know is that Morgoth made them from the vast (newer) delvings of Angband. These new delvings occured when Morgoth returned from his enforced stay in the house of his brother Mandos. In the Silmarillion it states:- But above this gate, and behind it even to the mountains, he piled the thunderous towers of Thangorodrim, that were made of the ash and slag of his subterranean furnaces, and the vast refuge of his tunnellings. They were black and desolute and exceedingly lofty; and smoke issued from their tops, dark and foul upon the northern sky. So, these lofty peaks seem less like great mountains, and more like huge chimneys for the darkness of industrialisation, something which pops up time and time again in the Life and Works of Tolkien. The towers of Thangorodrim are also described in The Silmarillion as reeking. It is possible that the strength of these towers have been somewhat overstated, Slag, ash and rock can be packed quite tightly, however, if reeking black smoke is issuing from fissures high on its peaks, it give thought to how that smoke gets there. I believe that it travelled up through the towers, therefore making the towers of Thangorodrim full of tunnels and cracks, and maybe very unstable.

[Formendacil]

One thing about this that has not been considered, I think, is the velocity with which Ancalagon smashed into Thangorodrim. Also, we have not considered the explosive potential of draco magnus pennatus*, which, after all, is capable of breathing fire (a known property of both the early, wingless drake model ala Glaurung, and the later winged dragon, Smaug).

Granted, I'm being a little bit facetious, but I am attempting to demonstrate that the destructive force of something need not be limited to them being dropped on something. If, for example, we imagine a giant cannon on Vingelot capable of shooting Ancalogon at Thangorodrim--and if we consider Ancalagon as a super-explosive living firecracker--we may be able to circumvent the "blue whale dropping" hypothesis.

Silly as I am being, after all, the Silmarils were anathema to evil, and we haven't exactly got details of Eärendil smiting Ancalagon--only the bare fact that he did, and the consequences. It's a bit cartoony, but imagine something like Ancalagon attempting to devour Eärendil, only to be repelled back to earth at thunderous speed when flesh touched the holy jewel, to explode as he hit the slopes of Thangorodrim. Admittedly, there's still a lot of room for hyperbole in this slightly ridiculous account...



*Great Winged Dragon, if my mangled, 2 second, Latin is right.

[Puddleglum]

Originally Posted by Ibrîniðilpathânezel

On the other hand, there is some precedent for Tolkien's fiery critters breaking mountains when they fall and die.

Originally Posted by Ibrîniðilpathânezel

Then again, maybe when these fire-critters fall and die, they explode in a nuclear fashion and flatten the landscape.

It's the "Dark Side" energy being released when they die <g>

Seriously, if you look at the other dragon deaths which Tolkien described, I think we have to allow for more than just a dead weight falling.

• When Glaurung was mortally stabbed, he started thrashing around breaking things.
• When Smaug received his mortal wound he shot spouting into the air, crashed down on Esgaroth, and completed the total destruction of the town by his death-flailings.

Also, if the "three peaks of Thangorodrim" were more in the style of mighty towers of slag and ash - then think how it only took a single Boeing 767 to bring down each of the WTC Towers on 9/11.
All it takes is for a thrashing Ancalagon (mightiest of the winged dragons) to weaken the supportting infrastructure of the towers enough (in his death throes) that they collapse under their weight - not unlike the WTC towers.

[Fordim Hedgethistle]

Pretty darn big.

[Galadriel55]

Ancalagon was "pretty darn big", whatever hyperbole Tolkien might have used. Big and powerful. I always thought that he only broke a part of Thangorodrim with his fall and thrashing, which was still a huge part. Perhaps he knocked off four mountains, maybe five, but definitely not the entire chain.
My answer as to why Orodruin errupted when the Ring was thrown in it: the Ring had so much power in it that when it was destroyed, the power caused the "natural disaster". It is also possible that the destruction is more near Mt Doom than any other place, because the Ring's power begun there; Sauron made it in Sammath Naur. I think that it is a metaphorical scene (about the Ring being thrown in, I mean), but exageration is also possible. I find a lot of Tolkien's exagerations to also be symbolic.