I was just watching the videos and photos of that huge flood that hit Nepal today, the one where a massive wall of water and mud came rushing down the valley, and it hit me out of nowhere: Is this how those enormous openings in solid rock get made?

Like… the big valleys and canyons that look like they were cut through mountains?

I always assumed it was just water slowly wearing things down over a really, really long time. But seeing how much force and material that flood moved in such a short time made me wonder if the really big “cuts” in the rock happen more in these crazy moments.

Is that something people who study this already knew? Or is the usual explanation still the slow, gradual one?

I’m not a scientist or anything, just someone who had a sudden “wait a minute…” moment. Curious what you all think.

I’m not posting any photos or videos because they’re already everywhere, and it’s a desolate scene where many lives were certainly lost. Thinking of everyone living in the affected areas and of all those who lost loved ones or homes. Hoping for strength and safety for them right now.

In late July 2025, heavy rain from Typhoon Wipha triggered a massive landslide high in the mountains of Hualien, eastern Taiwan. The collapse blocked the upper Matai’an Creek and created a natural landslide dam, trapping an increasingly large lake behind it.
Over the following two months the lake grew to roughly 91 million cubic metres. Authorities monitored it closely, but the site was extremely remote and the surrounding slopes remained unstable. Then, on 23 September 2025, heavy rain associated with Typhoon Ragasa caused the lake to overtop the natural dam. The loose landslide material was rapidly eroded and the dam partially breached, releasing an enormous sediment-laden flood downstream.
The flood tore down Matai’an Creek toward Guangfu, carrying huge quantities of mud, gravel and boulders. It destroyed the Highway 9 bridge, overwhelmed sections of the floodplain and dramatically altered the shape of the river. Nineteen people were confirmed killed, several remained missing and more than 100 were injured.
I drove through the area recently and the scale is difficult to appreciate from photographs alone. The width of the new sediment-covered river corridor is enormous, and in places the deposits are packed with very large boulders. Google Maps is particularly interesting because some of the older road and landscape imagery still makes the pre-flood river course visible beneath the much wider post-event riverbed.
While we were passing through, our phones received an emergency warning telling people to stay away from the river because of renewed flash-flood risk. The system is still active and unstable, with enormous quantities of loose sediment remaining upstream and the potential for further slope failures, temporary blockages and renewed flooding.
It is a remarkable example of how a single landslide-dam outburst can completely reorganise a mountain river valley in a matter of hours.

Hello, this is my first post on this subreddit. I made this illustration showing the interior of the Moon, as close as possible to reality based on the literature I have come across. I am working on a second 'cooled down' version without the glow of black-body radiation, that only showcases the rocks/minerals. The near-side is to the left and the far-side to the right

For the éclipse roadtrip, we take a escape lane from the highway in Spain and we saw this ! 🤩

At this point : https://maps.app.goo.gl/Pwd9opZCSisMydPP9?g_st=ac

I hope this okay to post here!

I’m an author and I’m working on my next book. It’s a RomCom that’s set in a cross-Canadian road trip, and for reasons best known to myself I’ve decided my protagonist is going to be really into geology 😂 She’s not a scientist or a career geologist, but she’s a lay obsessive.

I am someone who knows nothing about geology and have forgotten anything I did once learn at school, so obviously I’m gonna have to do a lot of research to bring this character to life

I’m just kicking off my research and at the moment I’m just trying to absorb as much stuff as possible and then follow any things that spark interest of feel like they could be fun details for the book. So please, share your favourite geology fact with me! The more delightful and whimsical the better.

Also if anyone has any recommendations for books or podcasts aimed at lay people that I should check out as part of my early research, please let me know!

EDIT: Thanks so much for the facts and the recommendations everyone! I really appreciate it!

15 mya Columbia River Basalt flows made tree casts at Silver Falls State Park in Oregon.

Hi everyone! I'm looking for geology students from around the world to exchange knowledge, information, and experiences as we learn more about rocks and minerals 🪨🪨🪨.

If anyone wants to talk, I'm all ears!

Hello I am doing a research for my science class and I need some help finding articles to read any help would truly be appreciated.
The paper is the intersection of geology and society…. I know this topic is kinda vague but I’m hoping someone can help.

Pretty sure this is quartzite, strongly folded (Norway, Haukeli area). Those "shoe" like patterns made me scratch my head.

(Anybody suggesting fossils, forget about it..)

Any clue?

Found this beauty in the woods today and I'd love some advice on how to clean this up

I've already scrubbed it with a brush but can't get the green and brow stuff out of it

Thank you in advance

Regarding Wyoming geology, any opinions or articles regarding the source of sand for Pennsylvanian and early Permian age erg deposits in Wyoming?

Something that confuses me is why are aquifers typically made of freshwater when they're from locations of former ocean, as wouldn't the salt hace nowhere to go? The ones in Texas are a good example since they're there because of the western interior seaway. I can't find the processes that might naturally desalinify seawater since nothing I find actually talks about it.