Technical question re: the God's Eye

[Illyrio Mo'Parties]

This might be a really stupid question.

The God's Eye is a lake, but it has a river leading to the sea. It also doesn't appear to be being fed by any other rivers, nor near any mountains or underground springs or what have you. In other words, the God's Eye appears to be full of water because it's a big enough hole in the ground that, once filled with water, the water won't evaporate fast enough to make the hole empty before it rains again. I presume this is how most lakes work. (See what I mean about a stupid question?)

But, again, this lake has a river, which means the God's Eye is constantly draining out to sea. And there's no other obvious source of replenishment for the God's Eye apart from the rain, so shouldn't the God's Eye, over time, have drained away?

Unless the Blackwater Rush isn't a river at all but a massive tidal inlet? But wouldn't that make the God's Eye saltwater - and choppy, being affected by tides?

 

[Wolf's Bane]

The snow melted at the end of the last Ice Age.  The water follows gravity and filled the low lands surrounding a hill.  What was once a hill surrounded by low lands is now an island in the middle of a great lake.  Runoff from the surrounding lands keep the lake full of water and a major tributary is not needed.  The river leading from the lake to the sea is overflow.

[Isobel Harper]

3 hours ago, Illyrio Mo'Parties said:

This might be a really stupid question.

The God's Eye is a lake, but it has a river leading to the sea. It also doesn't appear to be being fed by any other rivers, nor near any mountains or underground springs or what have you. In other words, the God's Eye appears to be full of water because it's a big enough hole in the ground that, once filled with water, the water won't evaporate fast enough to make the hole empty before it rains again. I presume this is how most lakes work. (See what I mean about a stupid question?)

But, again, this lake has a river, which means the God's Eye is constantly draining out to sea. And there's no other obvious source of replenishment for the God's Eye apart from the rain, so shouldn't the God's Eye, over time, have drained away?

Unless the Blackwater Rush isn't a river at all but a massive tidal inlet? But wouldn't that make the God's Eye saltwater - and choppy, being affected by tides?

 

It could be replenished by an underwater river, like those found in Bloodraven's cave.  

[BRANDON GREYSTARK]

Rippledown Rill fills the God's Eye .

[Jaak]

Look at how far the mapped rivers are from each other. Obviously a lot of smaller rivers and tributaries are omitted from the map.

The lake cannot drain by the river for the simple reason that the bottom of the river at outlet is higher than the bottom of the lake. If, in case of drought, the lake evaporated down to the level of outlet sill, the outflow river would become a trickle or completely dry, but the lake would remain.

The lake would be fed both by rain falling on water surface, and by water draining from the surrounding areas by a number of individually small, unmapped streams and by groundwater discharging at lake bottom.

An exercise you could try is: map not just rivers but also water divides...

[White Ravens]

On 3/11/2017 at 3:31 AM, Illyrio Mo'Parties said:

This might be a really stupid question.

The God's Eye is a lake, but it has a river leading to the sea. It also doesn't appear to be being fed by any other rivers, nor near any mountains or underground springs or what have you. In other words, the God's Eye appears to be full of water because it's a big enough hole in the ground that, once filled with water, the water won't evaporate fast enough to make the hole empty before it rains again. I presume this is how most lakes work. (See what I mean about a stupid question?)

But, again, this lake has a river, which means the God's Eye is constantly draining out to sea. And there's no other obvious source of replenishment for the God's Eye apart from the rain, so shouldn't the God's Eye, over time, have drained away?

Unless the Blackwater Rush isn't a river at all but a massive tidal inlet? But wouldn't that make the God's Eye saltwater - and choppy, being affected by tides?

 

Any lake in our own world ultimately gets its water from run-off from rain and melting snow/ice. The maps included with the books simply lack the detail needed to show all of the small streams and creeks that drain into the God's Eye and where the drainage divides are between all of the drainage basins in Westeros.

12 hours ago, BRANDON GREYSTARK said:

Rippledown Rill fills the God's Eye .

Rippledown Rill is the only small stream that GRRM mentions flowing into the God's Eye but there will be many others as well. 

[Weirwood Ghost]

The God's Eye is really the orifice of all the God's and was originally called God's Brown Eye

[White Ravens]

4 hours ago, Weirwood Ghost said:

The God's Eye is really the orifice of all the God's and was originally called God's Brown Eye

So, the water is replenished below the lake's surface by the underlying aquifer of the surrounding countryside? 

 

Ewww.

 

 

[The Great and Mighty Poo]

On 3/13/2017 at 0:07 AM, White Ravens said:

So, the water is replenished below the lake's surface by the underlying aquifer of the surrounding countryside? 

 

Ewww.

 

 

Dirt, rock, and sand beds naturally filter the water. Westeros doesn't suffer from man made chemicals so it will be "spring fresh" every time. 

You know where Aquafina or Dasani get their "spring fresh" water? From the tap. Haha, no joke.

Where I live both companies get it from Lake Michigan. I'm clueless where it's supplied in other paces in the country.

After I wrote that I realized it was completely arbitrary. My point still stands... I just got sidetracked.

[White Ravens]

3 hours ago, The Great and Mighty Poo said:

Dirt, rock, and sand beds naturally filter the water. Westeros doesn't suffer from man made chemicals so it will be "spring fresh" every time. 

You know where Aquafina or Dasani get their "spring fresh" water? From the tap. Haha, no joke.

Where I live both companies get it from Lake Michigan. I'm clueless where it's supplied in other paces in the country.

After I wrote that I realized it was completely arbitrary. My point still stands... I just got sidetracked.

Thanks for the reply.  I tried and failed to reply to the brown eye joke and bring the discussion back to the thread topic.  I had stated earlier in the thread that rainwater could account for the lake being there but of course aquifers and water flowing below ground would also serve as sources for water in the lake.  But the source of water for groundwater and aquifers is ultimately rainwater so same thing in a way.

[Maester of Valyria]

Lakes are fed through a combination of these mechanisms:

• Direct precipitation (ie rainfall) into the lake
• Surface run off, both in the form of water running over the ground and through small streams (here including Rippledown Rill and doubtless countless others)
• Throughflow (water moving through the soil)
• Groundwater flow (water moving through the bedrock)
• Springs feeding into the lake from below

The lake does indeed lose water from a combination of evaporation, outflow from rivers, and percolation (water seeping into the bedrock). However Jaak makes a very good point about the river, and the rest is a simple case of inputs > outputs.

On 12/03/2017 at 5:17 PM, Jaak said:

The lake cannot drain by the river for the simple reason that the bottom of the river at outlet is higher than the bottom of the lake. If, in case of drought, the lake evaporated down to the level of outlet sill, the outflow river would become a trickle or completely dry, but the lake would remain.

 

 

On 11/03/2017 at 2:39 PM, Steelshanks Walton said:

The snow melted at the end of the last Ice Age.  The water follows gravity and filled the low lands surrounding a hill.  What was once a hill surrounded by low lands is now an island in the middle of a great lake.  Runoff from the surrounding lands keep the lake full of water and a major tributary is not needed.  The river leading from the lake to the sea is overflow.

Love this idea Steelshanks

[The Great and Mighty Poo]

3 hours ago, White Ravens said:

Thanks for the reply.  I tried and failed to reply to the brown eye joke and bring the discussion back to the thread topic.  I had stated earlier in the thread that rainwater could account for the lake being there but of course aquifers and water flowing below ground would also serve as sources for water in the lake.  But the source of water for groundwater and aquifers is ultimately rainwater so same thing in a way.

Actually, your comment helps me alot because I couldn't remember if aquifers and plain-jane ground water or runoff were the same thing and I really didn't want to do a quick research because it really wouldn't be quick. I'd end up spending my day learning or relearning all about it and then some how find my self on a medical insurance blog.(furthest thing from intended subject I could think of. 

 

As to remain on topic. I'm pretty much sold, at this point, that it's run off feeding the lake. Or we could just say magic. What water magic would be needed to supply an endless amount of water?

 

On a side note- there was a thread awhile back about how an asteroid created the island. If this were to be true how does that affect the runoff or aquifers theory.... damn it! Now I'll be Googling when I get home. 

[Illyrio Mo'Parties]

Wow, I'm learning about lakes. Thanks a lot guys

So does this mean that the surface of the lake would be still? (At least the parts far away from the river)

[White Ravens]

1 hour ago, Illyrio Mo'Parties said:

Wow, I'm learning about lakes. Thanks a lot guys

So does this mean that the surface of the lake would be still? (At least the parts far away from the river)

It is a lake like any other lake.  Still when the weather is calm with waves that get bigger as wind speeds increase.

[Illyrio Mo'Parties]

1 hour ago, White Ravens said:

It is a lake like any other lake.  Still when the weather is calm with waves that get bigger as wind speeds increase.

Marvellous. And now I reveal my ulterior motive:

Quote

"Did your fires show you where to find this girl?"

"I saw water. Deep and blue and still, with a thin coat of ice just forming on it. It seemed to go on and on forever."

Mel's vision is of someone heading south past the God's Eye once winter has come. Calling it!

[Dorian Martell's son]

On 3/11/2017 at 3:31 AM, Illyrio Mo'Parties said:

This might be a really stupid question.

The God's Eye is a lake, but it has a river leading to the sea. It also doesn't appear to be being fed by any other rivers, nor near any mountains or underground springs or what have you. In other words, the God's Eye appears to be full of water because it's a big enough hole in the ground that, once filled with water, the water won't evaporate fast enough to make the hole empty before it rains again. I presume this is how most lakes work. (See what I mean about a stupid question?)

But, again, this lake has a river, which means the God's Eye is constantly draining out to sea. And there's no other obvious source of replenishment for the God's Eye apart from the rain, so shouldn't the God's Eye, over time, have drained away?

Unless the Blackwater Rush isn't a river at all but a massive tidal inlet? But wouldn't that make the God's Eye saltwater - and choppy, being affected by tides?

 

Arya encounters countless small streams swollen to near river sizes when she is trying to get to the trident to get back to her family. I am sure a number of theses drain into the god's eye 

[The Hidden Dragon]

Quote

"Did your fires show you where to find this girl?"

"I saw water. Deep and blue and still, with a thin coat of ice just forming on it. It seemed to go on and on forever."

The very next line in the book says "Long Lake".  You think the person in Mel's vision is someone other than Alys Karstark making her way to Castle Black?

[Illyrio Mo'Parties]

40 minutes ago, The Hidden Dragon said:

Quote

"Did your fires show you where to find this girl?"

"I saw water. Deep and blue and still, with a thin coat of ice just forming on it. It seemed to go on and on forever."

The very next line in the book says "Long Lake".  You think the person in Mel's vision is someone other than Alys Karstark making her way to Castle Black?

Yup. Even Mel doesn't think it's Alys Karstark - and why would Alys head north by west past Long Lake instead of northwest straight to the Wall?

[Maester of Valyria]

On 14/03/2017 at 6:08 PM, The Great and Mighty Poo said:

On a side note- there was a thread awhile back about how an asteroid created the island. If this were to be true how does that affect the runoff or aquifers theory.... damn it! Now I'll be Googling when I get home. 

Try this thread out:

I contributed quite a lot to it, and in my opinion it is well worth the read.