why does atlantis flood?

[Charles17]

shouldn't it be waterproof?
after all, it is airtight... if it's a spaceship...

unless the shield is the only thing keeping it from the vacuum of space. or the ocean.

[Stricken]

I think i know what you mean, In "Rising" the Shield was failing and water was comeing in as seen in "Before I Sleep" this is because the shield has been on for 10,000 years from when the Ancients left Atlantis in the hope to one day return, when we came along all those years latter, we started exploring not realising that the ZPM's were pretty much depleated and us going around turning on equipment in Atlanrtis drained the shield causing Atlantis to sacrifce parts the shiel letting in the ocean, whcih was seen in "Before I sleep"

[Charles17]

but... shouldnt the city be waterproof in the first place? i mean, if it's designed for spacetravel...

like in before i sleep and the city started to flood, someone asked if the puddle jumpers were waterproof and sheppard said 'they better be. theyre spaceships'

[Stricken]

The City of Atlantis is fragile (The Siege Part III + other eps) it cant withstand water thats why they have a shield

[mundu]

but... shouldnt the city be waterproof in the first place? i mean, if it's designed for spacetravel...

like in before i sleep and the city started to flood, someone asked if the puddle jumpers were waterproof and sheppard said 'they better be. theyre spaceships'

That's a very good point! Only thing I can think about is they are right at the bottom of the ocean and it's the pressure that is to powerfull for the hull.

[Charles17]

ooo thats a good point... yea i dont think the ancients were dumb enough to build such a huge city that's so fragile that it cant stand a little water... plus the materials atlantis is made of seems pretty resilient... it's lasted millions of years...

[Qtyled]

Little Water? Umm... how deep do you think the ocean would be? The deepest place on Earth is about 10km deep. There, the water exerts a pressure of 15,751 pounds per square inch. That is enough to crush all but the most resilient material.

As McKay said:
"The people who built this city knew they had a forcefield capable of holding back anything Mother Nature or, for that matter, the Wraith could throw at them. Without that protection, Atlantis is remarkably fragile."

[Qasim]

but... shouldnt the city be waterproof in the first place? i mean, if it's designed for spacetravel...

They probably use the shield in space aswell

[Steve_the_Wraith]

but... shouldnt the city be waterproof in the first place? i mean, if it's designed for spacetravel...

like in before i sleep and the city started to flood, someone asked if the puddle jumpers were waterproof and sheppard said 'they better be. theyre spaceships'

Without power Atlantis is as useful as a car with out fuel.

The Ancients never tought that the city would be without the power required raise the shield, they simply never conceived of situations like Rising and Storm. The "hull" isn't reinforced because with the shield down the city is doomed anyway.

But we do know from Before I sleep that the city has water proof bulkheads that shut to close off leaks. The entire Ocean pressing in on the city was just too much

[Gate_traveler]

another reason the city may have flooded is there are doors to access balconys and windows ad the like that may for lack of a better word not been closed. also im going to go with the forcefeild theory as well because in space travel there is alot of small debris that would penetrate the bulkheads heance venting of atmosphere would occur. however i think the zpm problem is only solved for now unless they find blueprints in the computers to build more or find for lac of a better work a intergalctic wal mart with racks of unused zpms ready for use.

[mundu]

Basically we don't know the depth of that ocean so it could be any depth and the pressure could be enough to penetrate the more susceptible areas of Atlantis.

Atlantis has to be airtight afaik because all ships we've seen use shields when nesacary and shields take up a lot of power and having the atlantis shield on takes up a lot of power as we know. And unless they have enough power to fly around space with the shields on I think it's pretty unlikely.

I think the quoted time a full ZPM would last again a Wraith attack was something between a few hours or days so times that by 3

[zer0_1]

i think they would only use the shields when nessacary
i.e. underwater, in space or under attack
other wise, theyc ould switch them off and turn them on when need be

[Mattathias2.0]

Turning off the shield may be an option... but not one someone should do.

[Steve_the_Wraith]

I think the quoted time a full ZPM would last again a Wraith attack was something between a few hours or days so times that by 3

In the same episode McKay said the shield can run indefinitly when not under attack. You have to remember that when the city was built the ancients ruled an entire galaxy unchallenged - Atlantis was probably never designed to withstand a siege. Its impossible to know how "full" the ZPMs were that the Ancients left behind on the city or the one found in Egypt was. Even then the sheilds lasted for 10,000 years - thats a long time!

[MarshAngel]

Atlantis is a city first and a ship second. It was designed for comfortable living above water not for prolonged space travel or sitting on the bottom of the ocean. It seems the Ancients had other options for both. If the city were watertight and designed for the stresses of water pressure it wouldn't be as attractive or as comfortable place to live for the long periods of time the ancients lived on it, and the constant maintenance of keeping it that way would defeat the purpose of building a city of that kind. Without a shield, even the hardest materials would probably deteriorate with the stresses of being at the bottom of the ocean, so if you're going to have a super shield why not live well, there's more than one way out should anything happen: ships, pjs, a stargate.

If they wanted to live in absolute secuity, they would have lived on their other ships. It seems the ancients planted Atlantis where it is and then used it as a base; somewhere comfortable to come home to after hanging out in smaller crafts for a long time. They seemed to have left most planets to human civilizations so they needed a place that was all their own.