I was on a hike and read a plaque that said this area used to be completely covered by water. My question is, where did all that water go? Just absorbed into the ground? Evaporated?
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Lots of different things OP.
Water could’ve gone underground, it also could’ve been absorbed in some extent by the biosphere (trees, plants, etc). Water inside of you means water that isn’t on the ground after all. You could also have water that’s in the air, climate change is infamous for increasing global temperatures and hotter air holds more water in it.
Also glaciers! Yeah a whole lot of places it could be
It’s not the water that changed but the geology.
Duo to the movement of continental plates, some parts of the planet were once ocean floor but have been pushed above water.
It is not so much a question of where the water goes but where the ground goes.
You can climb up Mount Everest and find marine fossils. This means that at some point the highest ground we have on the planet was once under water.
This does not mean some biblical flood, but rather that the ground moves. Continental drift and plate tectonics move landmasses around and like in the case of the Himalayas ocean floor may be piled up into tall mountains.
There are many places that were once dry land that are now under water and others that were covered in water are now dry land.
For example when Dinosaurs still roamed the land the center of what is now the US was covered in a great shallow ocean that connected the gulf of Mexico all the way up to the arctic ocean.
As recently as a few thousand years ago what is now Britain was connected to the rest of Europe by a landmass which existed where now there is the north sea.
Between the changes in climate and Continents drifting about how much of the world was covered in water changed over the ages
There are some theories that in the very distant past like 3 billions of years ago all the world or almost all of it was covered in water.
Depends on what area you were at precisely, but the water most likely didn’t go anywhere, it’s the ground that moved. Some areas the ground is lifting up, the others it’s sinking, Earth isn’t so rock solid over geological timeframes.
The peak of Everest used to be seafloor. It doesn’t mean that back then the sea is as high as Everest, it’s that Himalaya is a relatively young mountain that are created by Indian plates pushing north, thus pushing what was once seafloor into mountain peak. Sometimes the otherway happens. Like how it’s theorized that Doggerland, which was a seafloor now, used to thrive with humans, the end of ice age however floods the area and pushing humans to higher grounds, British isles and mainland europe. Before you think of normal floods though, do remember these happens within 300 years, so it’s more like the humans realize that the shore gets closer and closer every weeks/month until separating the isles from mainland more than instant flooding.
Once upon a time there was an ocean (or maybe a sea, or a lake?). Over time, sediment (sand and silt) settled on the bottom of that ocean. Eventually that sediment was buried so deeply, and was under so much pressure and heat that it became rock.
While this was happening, the continents slowly drifted, and in some places, this caused the rock to be pushed upwards, until it was no longer under water.
So the water didn’t go anywhere. the sea-bed was lifted up until it was above water.
Sea levels have changed over time (e.g. due to melting and freezing of the ice caps) but in that particular case it’s more likely that the spot you were on used to be at a much lower elevation, and geologic activity has pushed it up above sea level.
Fun fact: the very top of Mount Everest is made of grey limestone, which only forms in underwater environments, and contains fossils of marine organisms. So around 450 million years ago, it was underwater too.
If all ice on Earth melted the global sea level would rise approximately 70 meters (approximately 230 feet).
That’s a lot of water. There have been periods in the past when the water level was much different compared to today.
Another thing is that geography changes over time. How high above the see level something is today doesn’t mean it wasn’t under water at some point.
This depends a lot on where you are, but in certain parts of the world the ice sheet during last ice age was several kilometers thick. All that mass of ice pushed ground down, over a kilometer in some places. After the ice age, the ground begun to rebounce, and it’s still raising to this day.
If there were no mountains, valleys, hills or changes in elevation at all. If the entire crust was a perfect sphere, there would be enough water to cover it 1.68 miles deep. Even if you only include the oceans, it’s still 1.62 to 1.63 miles deep. So we’re very lucky that tectonic activity changes the landscape. Fissures can create volcanos, plates crashing into each other push up mountains, both will push water out of the way as they rise.
It also depends on how long ago we’re talking. If it’s Pangaea, that’s only like, a couple hundred million years ago. The atmosphere and climate aren’t going to be insanely far off from what they are right now, but a couple billion years ago, we’re talking proto-Earth where weather would have been unrecognizable. It started off super hot so there would have been an insane amount of water evaporated in the atmosphere. As it cooled down, that rain likely lasted for centuries. There would have been phenomenal flooding. Once the rains finally ceased, a more stable equilibrium could be found where evaporation rate more closely matches rain
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