Both ends of the Portal are 60 meters in diameter, and are halfway submerged into the lakes at each end. Each end of the portal is located at the point of the lake farthest from shore.

Assume that the portal is indestructible, and massless. No black hole or other weirdness will result from this fictional portal's existence. They are bridging two points in space-time and that is all.

What will be the climatic, and physical changes on Earth, and Titan as a result of this?

Edit: It was suggested that I make my question more specific. So what would be the long-term effect on North America's climate as a result of this portal's existence?

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    $\begingroup$ This is a very broad what if question about a single event that occurs in a world. Is there something specific you're interested in knowing about. I think that accounting for every change to both Earth and Titan, is too broad an ask for a single question on this site. $\endgroup$
    – sphennings
    Jul 28 at 1:17
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    $\begingroup$ @sphennings; my humble opinion which nobody asked for is that this question is in the spirit of this very popular question which holds just about as much specificity when asking for 'what happens when'. The question feels fine as is (although of course more information is always welcome if relevant). $\endgroup$
    – user97385
    Jul 28 at 1:27
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    $\begingroup$ @futurelamb Site policy has evolved a lot in the past five years. Currently broad asks aren't appropriate on this site. We're a worldbuilding site not a what-if site. $\endgroup$
    – sphennings
    Jul 28 at 1:51
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    $\begingroup$ @sphennings The Wayback Machine records of the relevant site pages at the time that previous question was asked, do not appear to be so different to what they are today, in such a way that would allow such a question then, but disallow it now. $\endgroup$
    – user97385
    Jul 28 at 1:59
  • $\begingroup$ Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. $\endgroup$
    – Community Bot
    Jul 28 at 2:33

1 Answer 1


You will partly drain Lake Superior into Kraken Mare. Until the ice mound plugs the portal.

The atmospheric pressure on Titan is 150% that of Earth.


The surface pressure is about 50% higher than on Earth at 1.5 bars (147 kPa)[1] which is near the triple point of methane and allows there to be gaseous methane in the atmosphere and liquid methane on the surface...

The two lakes are comparably deep (400 m). Liquid methane is 65% the density of water. The pressure at 200m of water is about 20 bars and so the pressure at 200m of methane is 13bars. 20 bars for depth + 1 for atmosphere = pressure of 21 bar on Earth side. 13 + 1.5 = 14.5 on Titan side.

Pressure is higher on the Earth side so water will leave Lake Superior and flow to Titan. Ice is denser than liquid methane so it will sink into the methane lake. The methane lake will boil because of the heat of incoming water. As Superior drains, the pressure of overlying water will decrease but the overlying methane pressure is decreasing too as it boils away. Kraken Mare is much bigger than Superior and so I think the level will change less there.

Flow will stop when pressure has equilibrated. I figure that will be when the level of Superior has dropped 132 meters.

It will stop before then if enough ice has piled up around the portal on the Titan side to occlude the portal on that side. This might happen long before Superior drops appreciably. If the ice piles as a cone, a cone 200 meters high and 200 meters diameter has a volume of about 2 million cubic meters or 2 billion liters. The Great Lakes contain 22 quadrillion liters. 2 billion is a drop in the bucket.

Climactic changes on Earth will be those that result from a very slightly smaller Great Lakes.

Climactic changes on Titan will be rain as methane boiled off the lake condenses and rains back down.

Investors in an awesome portal between worlds might be disappointed.

  • $\begingroup$ There's trouble here, my interpretation of half submerged was that the lower half of the mouth of the pipe was under water/methane, the rest being in atmosphere. $\endgroup$ Jul 28 at 1:54
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    $\begingroup$ @AngryMuppet - I see how it could be taken that way. The OP will have to clarify. If you are right then the atmospheres are in contiguity and the liquids and lakes are irrelevant; Titan vents atmosphere to Earth and the liquids do not move. $\endgroup$
    – Willk
    Jul 28 at 2:05
  • $\begingroup$ Since Titan is at higher pressure, wouldn't the flow be the other way (at least on top)? Although Lake Superior would rapidly freeze as hard as rock, and a huge cloud of explosive volatilized methane will pour in and start mixing with the oxygen, waiting for the first spark from human observation planes that would inevitably show up... $\endgroup$
    – DWKraus
    Jul 28 at 2:20
  • $\begingroup$ @DWKraus - yes; if atmospheres are connected Titan will vent atmosphere to Earth. It would spread out across the lake but I think the top layer of ice will insulate the lake below. Superior has practice with that,. As regards blowing up the methane will surely oxidize eventually one way or another. $\endgroup$
    – Willk
    Jul 28 at 2:29
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    $\begingroup$ @WhatIfEnjoyer568, yes, there will be energy flow. No, it won't be very fast. Ice is a pretty good insulator. $\endgroup$
    – Mark
    Jul 28 at 2:50

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