Green Mars(198)
Diana took the wheel and drove them northeast, paralleling the canyon rim on a road that ran next to the massive concrete foundation for the canyon’s tenting. Even though the fabrics were diaphanous to the point of vanishing, the sheer size of the roof made it a heavy weight to anchor. The concrete bulk of the foundation blocked their view down into the canyon itself, so that when they came to the first overlook, Maya had not seen into it since Hell’s Gate. Diana drove into a little parking lot up on the broad foundation itself, and they parked and put on helmets and got out of the car, and walked up a wooden staircase that seemed to ascend freestanding into the sky, although a closer look revealed first the clear aerogel beam supporting the staircase, and then the layers of tenting, stretching away from their beam to others that could not be seen. At the top of the stairs was a small railed viewing platform, with a prospect that gave a view of the canyon for many kilometers both upstream and downstream.
And there was indeed a stream; the floor of Dao Vallis had a river in it. The canyon floor was dotted with green, or to be more precise, a collection of greens. Maya identified tamarisk, cottonwood, aspen, cypress, sycamore, scrub oak, snow bamboo, sage— and then, on the steep talus and boulder slopes footing the canyon walls, many varieties of shrubs and low creepers, and of course sedge, and moss, and lichen. And running through this exquisite arboretum, a river.
It was not a blue stream with white rapids. The water in the slower stretches was opaque, and the color of rust. In the rapids and waterfalls it foamed bright shades of pink. Classic Martian tones, caused, Diana said, by the fines that were suspended in the water like glacial silt— also by the reflected color of the sky, which was today a kind of hazy mauve, going lavender around the veiled sun, as yellow as the iris of a tiger’s eye.
But no matter the color of the water— it was a running river, in an obviously riverine valley, placid in some places, agitated in others, with gravel fords, sandbars, braided sections, crumbling lemniscate islands, there a big deep lazy oxbow, frequent rapids, and far upstream, a couple of small falls. Under the tallest waterfall they could see the pink foam turn almost white, and patches of white were then carried downstream, to catch on boulders and snags sticking out from the bank.
“Dao River,” Diana said. “Also called the Ruby River by the people who live down there.”
“How many are there?”
“A few thousand. Most live pretty close to Hell’s Gate. Upstream there are family homesteads and the like. And of course then the aquifer station at the head of the canyon, where a few hundred of them work.”
“It’s one of the biggest aquifers?”
“Yes. About three million cubic meters of water. So we’re pumping it out at a flow rate— well, you see it there. About a hundred thousand cubic meters a year.”
“So in thirty years, no more river?”
“Right. Although they could pump some water back upstream in a pipe, and let it out again. Or who knows, if the atmosphere gets humid enough, the slopes of Hadriaca might collect a snow-pack big enough to serve as a watershed. Then the river would fluctuate with the seasons, but that’s what rivers do, don’t they.”
Maya stared down at the scene, which looked so much like something from her youth, some river . . . the upper Rioni, in Georgia? The Colorado, seen once on a visit to America? She couldn’t recall. So fuzzy, all that life. “It’s beautiful. And so . . .” She shook her head; the sight had a quality she could not recall ever seeing before, as if it were out of time, a prophetic glimpse into a distant future.
“Here, let’s go up the road a bit farther and see Hadriaca.”
Maya nodded, and they returned to the car. Once or twice as they continued uphill, the road rose far enough above the foundation to give them another view down onto the canyon floor, and Maya saw that the little river continued to cut through rocks and vegetation. But Diana did not pause, and Maya saw no sign of settlements.
At the upper end of the tented canyon there was a big concrete block of a physical plant, housing the gas exchange mechanisms, and the pumping station. A forest of windmills stood on the rising slope to the north of this station, the big props all facing west and slowly spinning. Above that array rose the broad low cone of Hadriaca Patera, a volcano whose sides were unusually furrowed by a dense crisscrossing network of lava channels, the later ones cutting over the earlier ones. Now the winter’s snowpack had filled the channels, but not the exposed black rock between them, which had been blown clear by the strong winds accompanying the snowstorms. The result was an enormous black cone sticking into the bruised sky, festooned with hundreds of tangled white ribbons.