Where did all the water go?!?

[baldkev]

I recently took the kids to lyme regis to go fossil hunting. The eroding land which gives up the fossils was once a seabed.... under lots of water, so where did it go?
A quick google shows the ocean holds 97% of the worlds water, just 3% in the atmosphere and snow/ ice, so we seem to be missing some! Quite a bit it seems?

This is a genuine question btw!

 

[Phil Pascoe]

Land mass shifts.

 

[baldkev]

Do you mean the coast in england has risen up out of the water?
Lake mead in the u.s has dropped around 300 feet in 2 and half years due to drought, yet the arctic shelf is disintegrating due to heat. Shouldnt that heat cause sea water to be evapourated and sent back as rain, or is the sea mass too chilly to get much evaporation? Maybe just the land based water gets evaporated ( mostly ) hence the drought?

 

[ajs]

The south of the country as a whole is sinking. The north sunk under the weight of ice in the last ice age and it is still rising up now the pressure is off, the south is sinking in consequence. It probably was underwater before the ice age, or when sea levels were higher than they are now.

 

[clogs]

Aliens……lol….

 

[Jacob]

Where we are the local stone is limestone which was formed in the sea 3.5 million years ago but is now 1000ft above sea level!
The making of an island

 

[rogxwhit]

The land isn't static. Mountains are eroded constantly but in such slow time that we hardly notice. But their material ends up in the sea. Such a huge weight of material turns to rock. Also, volcanoes emit material that settles to form other kinds of rock. Altogether like a giant layer cake.

All the land is on floating plates & when these collide, one is submerged back down into the hot stuff beneath and the other rides up and new mountains are formed.

That's the extra-short version, anyway ....

The isostasy mentioned in post 4 is just a detail in the bigger scheme.

 

[johna.clements]

The Alps were formed by Africa floating north and hitting Europe pushing up the rock in the "crumple"zone. In other places the sea bed may be forced down. The higher land in the UK was mostly formed the same way. Then water, the wind, ice etc slowly grind it all down and the seas fill up with new rock layers.

If there is less mountain building and more erosion the rock that is the seas will fill into some extent and raise the sea level slightly. And the converse. But the continents move very slowly pushing up new mountains and the mountains take a very long time to erode so any changes in sea level will not be noticed by us.

If you look at the cliffs at Lyme Regis you will notice that the tops are slopping down to the east then there is a step up and a different layer slopes down to the east. The higher rocks are younger and when they were pushed up they were also tilted.

 

[Droogs]

Lyme Regis when it was a seabed which was roughly 400m years ago was also roughly where Panama is now. Over time plate tectonics have raised and moved it. Just like the mountains in Scotland are regarded as the oldest mountain range on earth and formed when the N American and Eurasian plates first met 300m years ago and where once as high as the Himalayas but have worn down to nubs of what they were do to erosion. The most amazing fact to me regarding geology is that the mountains we see today and regard as solid are in fact a slow moving viscous fluid and are in fact merely slow motion waves from where the plates crash into each other. The mountains of Nepal are in fact the crest of the Himalayan range and are ever so slowly cresting over onto India.
The shear scale of it all baffles our tiny brains and it is hard to conceive that all the fresh water currently sitting on land (in all forms) could evaporate into the air and only raise humidity by around 2%

 

[Terry - Somerset]

The total volume of water on earth is a constant (but see below), although some of it is stored as ice and plays no part in events unless it melts. As the land moves - volcanoes, earthquakes, tectonic plates etc - so the water moves to equalise the level.

About 300m years ago there was one land mass on earth - Pangea. This broke up to create the separate continents we see today. Whether this was an island in an ocean, or a lake in a land mass is debatable.

Total volume of water is not a constant - sea levels will change due to both melting of ice caps, and equally important, thermal expansion of sea water. There is a timing difference - the ice melts sooner than the sea temperature increases!

 

[johna.clements]

Some water will be trapped chemically in rocks. I the distant past water was added by meteor etc strikes.

Water can also end up in aquifers.

 

[niall Y]

The existence of 'Himalayan Salt' does illustrate how mind-boggling the whole thing is.

 

[Yojevol]

@Droogs A bit of correction to the above. Only a few hundred million years.
The limestone at Lyme Regis was laid down in a shallow sea late in the Upper Jurassic period. The Jurassic as a whole covers the period from 208-146Ma (Ma=million years ago). The Lyme Regis layers would have been late in that period, say 150Ma. At that time the shallow sea would have been further south at 30-40deg - present day Gibraltar is at 36deg.
Brian

 

[baldkev]

Its amazing how much knowledge is accumulated on one forum

 

[Yojevol]

I recently took the kids to lyme regis to go fossil hunting. The eroding land which gives up the fossils was once a seabed.... under lots of water, so where did it go?
A quick google shows the ocean holds 97% of the worlds water, just 3% in the atmosphere and snow/ ice, so we seem to be missing some! Quite a bit it seems?

This is a genuine question btw!

The quick answer to 'where did it go?' is that it didn't go anywhere It wasn't that the sea level went down, it was that the land mass came up. You were in the right place at Lulworth Cove to see spectacular examples of folding due to tectonic plate movement:-

However the gut response to your question has proved to be a bit hasty. Another quick google has come up with this:-

It shows that sea level has fluctuated enormously over the last 542 m.years and wildly over fairly short periods.
The main explanation seems to be that it's the result of climate change causing water to freeze/thaw and secondly, expansion/contraction with temperature change.

Brian

 

[Spectric]

the south is sinking in consequence.

Thats because of how many people live down there and the number of 4x4's !

In years to come people who are currently inland will get sea views as the coast errodes and the sea rises.

The total volume of water on earth is a constant

Is that not before we went into space, they must take fluid to drink and do they bring there pee home or leave it orbiting the planet.

 

[Terry - Somerset]

Is that not before we went into space, they must take fluid to drink and do they bring there pee home or leave it orbiting the planet.

You are of course quite right this could be an issue - additionally underground aquifers, lakes, moisture content of trees and peat bogs etc etc would all conspire to make the calculations off sea level rise, subduction and calculated movement of tectonic plates inaccurate.

A bit like adding a thimbleful of cold water to an Olympic size swimming pool and trying to understand the impact on the athletes performance.

 

[dickm]

LyJust like the mountains in Scotland are regarded as the oldest mountain range on earth and formed when the N American and Eurasian plates first met 300m years ago and where once as high as the Himalayas but have worn down to nubs of what they were do to erosion.

And, of course, it was looking at the mountains in Scotland that gave James Hutton the ideas that underpin modern geology. Can't remember the names of the two guys who researched round Assynt and built on his ideas, but there is a nice statue of them in the interpretation centre there. What's particularly good is that they've also put a statue on the other side of the centre representing a "modern" geologist, who is young and female!

 

[Jacob]

And, of course, it was looking at the mountains in Scotland that gave James Hutton the ideas that underpin modern geology. Can't remember the names of the two guys who researched round Assynt and built on his ideas, but there is a nice statue of them in the interpretation centre there. What's particularly good is that they've also put a statue on the other side of the centre representing a "modern" geologist, who is young and female!

One of the early bods:
"Old Red Sandstone or, New Walks in an Old Field", by Hugh Miller
https://en.wikipedia.org/wiki/Hugh_Millerhttps://www.gutenberg.org/files/63923/63923-h/63923-h.htm
"Mr. Miller is one of the few individuals in the history of Scottish science who have raised themselves above the labors of an humble profession, by the force of their genius and the excellence of their character, to a comparatively high place in the social scale."
— Brewster (1851)

 

[baldkev]

The quick answer to 'where did it go?' is that it didn't go anywhere It wasn't that the sea level went down, it was that the land mass came up. You were in the right place at Lulworth Cove to see spectacular examples of folding due to tectonic plate movement:-

View attachment 139666

However the gut response to your question has proved to be a bit hasty. Another quick google has come up with this:-

View attachment 139667

It shows that sea level has fluctuated enormously over the last 542 m.years and wildly over fairly short periods.
The main explanation seems to be that it's the result of climate change causing water to freeze/thaw and secondly, expansion/contraction with temperature change.

Brian

Thanks for that Brian. Interestingly, the climate change can only really have happened since the industrial revolution and that would presumably have been fairly minor at start ( compared to the massive effect we make today ).... so presumably you'd expect to see a bigger spike in the last 30 years.
I still cant believe there are people who think its fake..... all the millions of things the world produces, plus the factories that make the stuff, shipping, disposal, mining, batteries, its endless.... then theres bitcoin! Which creates a huge climate issue due to exponentially larger power consumption as time goes on. The heat, gases etc is unthinkable

Thats because of how many people live down there and the number of 4x4's !

Ive got a 4x4