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We set up camp on the Thwaites Glacier, about a hundred kilometers inland from the coast of Antarctica. Thwaites was chosen because it was one of the fastest-moving big glaciers, combined with a fairly narrow gateway to the sea relative to other glaciers in its class. There were about fifty glaciers in Antarctica and Greenland that were going to dump ninety percent of the ice that was going to end up in the sea in the next few decades, and in that group, this one looked like one of the best test subjects. So there we were.
The camp was a typical Antarctic field camp, of the larger variety. A runway long enough for C-130s was secured; this meant landing first in Twin Otters, then checking a two-mile stretch of ice to make sure there weren’t any unseen crevasses. Blow up and bulldoze any crevasses you find. Eventually you get a full landing strip. After the C-130s could land, a few Jamesways were flown in and assembled to serve as galley and commons. These Jamesways are basically insulated Quonset huts of World War Two vintage: they are floored half cylinders, very simple, easy to assemble, and pretty energy efficient. These that we set up were powered and heated mostly by solar panels, as this was a summer camp and the sun would be up all the time. A few tents for people who liked to sleep away from the huts— I’m like that myself— and a couple of yurts like the Russians use. When we were done we had a little nomad village, colorful against the white background: yellow, orange, khaki, red.
The drilling equipment was one of the ice coring systems that have been operated for a long time in Antarctica to get core samples, or drill down to subglacial lakes, or get through an ice shelf to the ocean below. They shoot hot water at the ice through a thing like a giant shower head, and melt it. As the ice melts the drill head goes lower, and down it all goes. The meltwater gets pumped out, and the hole can be sleeved with a heated sleeve if you want to keep it open, which we did. Some of the meltwater gets recycled into the drill head’s feeder tank to be reheated. The rest gets piped away and dumped where it can spill out and freeze without messing anything up. Progress down the hole is slow by some standards, fast by others. A typical speed for a two-meter-diameter hole is about ten meters per hour. Fast, right? It’s a lot easier than drilling in earth or anything else hard, although you do need a lot of power to heat the water. That used to mean burning a lot of diesel fuel, but solar will work too if you’ve got enough of it.
This time, when we got to the bottom of Thwaites, about nine hundred meters down from the surface, water came up the hole, but not all the way to the surface. It was under stupendous pressure from the weight of the ice on it, but no matter how thick the ice, the water under it gets shoved up the hole only about ninety percent of the way. The physics of hydrology dictates this, although we ran a pool anyway to see who could guess the actual height of the rise the closest, because there are always variants in play that mean the actual level in the hole will range a few meters one way or the other. In any case about ninety percent of the way to the top, so the energy needed to pump water the rest of the way to the surface was not that great. So we did that, but no matter how much we pumped out, it was replenished from below. This was the crucial question; could we empty out the water down there? Would we be able to pump up so much that there was nothing left to pump?
There turned out to be a lot of water under the Thwaites, as predicted. Bigger and bigger summer pools of meltwater on the surface had run down moulins, which are like vertical rivers that run down cracks in the ice. That water bottoms out on the bedrock and then lubricates the slide of the ice over it, until the ice is like riding down a water slide. The glaciers are therefore becoming more like rivers than ice fields, flowing almost as fast as some flat-country rivers, but with a hundred times more water in them than the Amazon, or even more. And the water in the Amazon was rain the week before, but the ice in Antarctica has been perched up there for the last five million years at least. So we’re going to see sea level rise, big time.
So if we could pump that subglacial water out from under the glacier, the ice would thump back down onto bedrock and slow down to the grind-it-out speed that used to be normal. After that we would keep pumping subglacial water out, and the ice would stay grounded on the bedrock, and it would stay at its old speed, deform viscously, shatter in crevasse fields, all the usual behaviors, and at the old speeds. Thus the plan.
We were here to test the method. Some said the water at the bottom would get mixed with glacial silt until it was the consistency of toothpaste, and hard or impossible to pump up. Others said the silt was long since gone, the bottom clean as a whistle after millions of years of scraping, and the new water down there would be
