So my uncle has a PhD in geology so I asked him some questions, I figure if anyone would know, it would be him.
It’s actually kinda interesting, and I don’t understand all of it, and I might be getting parts wrong. But there are 4 layers to the earth: crust, mantle, outer core, inner core. I think the outer and inner core can together rightly be called the “center” of the earth. The outer core is liquid, the inner core solid. There are no “layers” of lava, just the outer core and pipes from the outer core to the crust. So my uncle says, there are large areas in the mantle that aren’t lava but soft mushy solid that they could conceivably dig through.
Also, the earth is cooling, someday it will be cold like the moon. And it’s cooling from the inside out. At one point the outer core will no longer be liquid and will merge with the inner core. At which point there won’t be lava either, so if the earth has reached this point, again, no lava problems.
Also, it’s not pressure that responsible for lava. It’s a contributing factor, uncle says, but the biggest thing is the heat from the earth’s core. So there’s lava because it’s nearer the core which is hot. The source of the heat isn’t the pressure, else the earth wouldn’t eventually get cold, it would stay the same temperature, since the pressure doesn’t change. Er, the pressure independent of temperature. If that makes any sense.
Point is, there are no lava issues with Zion.
The pressure is a problem though. Huge problem. He’s OK with it though, because it’s far in the future and they will have come up with really smart things.
Did anyone care about this entry? Doubtful. I dunno, I just think it’s cool having an uncle with a PhD in Geology.