Red Mars (79 page)

And without a doubt the southern wall would be collapsing in a similar way, although their view of this wall, which loomed over their road to the right, was foreshortened and cut off. But it had to be falling. And if it flaked off above them, then they were dead for sure. It was quite possible— very possible. Judging by her glimpses of the north wall, the chances might be as high as 50 percent. But then it was probably worse over there; the northern wall appeared to be undercut by the flood, while the south wall was removed from it by the bench they were driving over. So the southern cliffs should be a bit more stable—

But then something drew her eye forward, downstream from them. Up there the south wall was indeed collapsing, falling in great sheets of rock. The base of the cliff exploded in a cloud of dust that bloomed over the talus, and the upper sections of the cliff slid down into this new cloud of dust and disappeared. After a second the whole mass reappeared flying horizontally out of the cloud, a strange sight. The noise was painfully loud, even inside the car; then it was just a long slow landslide down into the flood, the rocks crushing the ice and blocking the flow beneath. An instant dam, cutting off much of the flow down-canyon; and so the banks of the flood began to rise. Ann watched the icy sheet of the shoreline below her rupture, and then it was chunks of ice, jostling in a sea of black smoking fizzing water, rising swiftly toward the rover. It would engulf them if the land-slide dam lasted long enough. Ann peered at the long black spill of rock ahead of them; only a strip of it was still visible above the flood. But the slush beneath her continued to rise. It was a race of sorts. Big Man’s bathtub, draining while he poured new bucketfuls in. The speed of the lake’s ascent caused Ann to raise her estimate of the flow rate. She felt paralyzed, disconnected, in some curious sense serene; it was a matter of indifference to her whether or not the dam broke before the flood reached them. And in the overwhelming roar she felt no need to communicate with the others about this; it was impossible. She found that in a way she was cheering the flood on. It would serve them all right.

But then the landslide dam disappeared under the discolored slurry, and it all rolled off downstream in a stately collapse, the short-lived lake dropping as she watched, ice blocks on its surface clattering together, shrieking and booming as they collided and jumbled around and shot high into the air, all fantastically loud, every audible pitch roaring at once. It had to be well over a hundred decibels. She had her fingers in her ears. The car was bouncing up and down. She could see more landslides from the cliffs farther downstream, no doubt undercut by the sudden surge of the flood; the tremors they caused were triggering further collapses, until it looked like the whole canyon would fill. It seemed impossible in all the noise and vibration that their little cars would survive. The travelers clutched their chair arms or lay there on the floor like Ann, isolated by the roar, their veins pumping with an awful mix of ice and adrenaline; even Ann, who did not care, found her breath short and her muscles tensed against the kinetic assault.

When they could hear each other’s shouts again, they asked Ann what had happened. Dully she stared out the window, ignoring them. Apparently they were going to survive, for the moment at least. The flood surface was now the most shattered chaotic terrain she had ever seen, the ice pulverized to a plain of wicked shards. The high point of the lake had climbed their bench until it had been only a hundred meters downslope from them; the reexposed wet ground down there had turned from rusty black to dirty white in less than twenty seconds. Freezing time on Mars.

Sax had stayed in his seat through all that, absorbed by the flickering on his screen. A lot of water would evaporate, or rather freeze and sublime, he muttered to no one as he worked. It was very pure water, almost distilled, but it would end up as dust-filled snow, falling somewhere else. The atmosphere might get hydrated enough so that it would snow several times, or even on a regular basis, in cycles of precipitation and sublimation. Thus the floodwater would get distributed pretty evenly planetwide, except perhaps at the highest altitudes. Albedo would rise dramatically. They would have to lower it, presumably by encouraging the snow algae that the Acheron group had created. (But there was no more Acheron, Ann said to him in her mind.) Black ice would melt by day, then freeze at night. Sublimate and precipitate. And thus they would have a waterscape: streams collecting, pooling, running downstream, freezing and expanding in cracks in the rock, subliming and snowing and melting and running again. A glaciated or muddy world, most of the time. But a waterscape nevertheless.

And every single feature of the primal Mars would melt away. Red Mars was gone.

Ann lay there on the floor by the window. Her tears poured out of her to join the flood; over the dam of her nose, downstream until her right cheek and ear and the whole side of her face was wet.

“This will complicate the process of getting down-canyon,” Michel said with a little Gallic smile, and from the next car Frank laughed. In fact it looked as if it would be impossible for them to proceed even five kilometers. Directly before them the canyon highway was buried under the great landslide, completely gone. The new spill of rock was shattered and unstable, sapped from below by the flood, pounded from above by subsequent mass wasting of the new slope.

For a long time the others debated even making a try. They had to speak loudly to be heard over the jet-engine roar of the flood, which still swept past with no sign of a let-up. Nadia considered the slope suicidal, but Michel and Kasei were pretty sure they could find a way, and after a long day’s reconnaissance on foot they managed to convince Nadia to agree to try it, and the rest were willing if Nadia was. And so the day after that, protected from surveillance by the general dust storm and the flood’s steam, they divided into the two cars and drove slowly out onto the slide.

It was a rough mass of gravel and sand, liberally sprinkled with boulders. There was, however, a zone corresponding to the bench below it, which was relatively level. This zone was the only thing that made passage possible; it was a matter of finding an unobstructed way over a surface like poorly mixed cement, around boulders and past the occasional gaping hole. Michel drove the lead car boldly, with a stubbornness verging on the reckless. “Desperate measures,” he declared cheerily. “Can you imagine getting on this kind of ground in the normal course of things? It would be insane.”

“It’s insane now,” Nadia said sourly.

“Well, what can we do? We can’t go back, and we can’t give up. These are the times that try men’s souls.”

“Women, however, do fine.”

“I was quoting. You know what I mean. There’s simply no possibility of going back. The head of Ius will be flooded wall to wall. I suppose it’s this that makes me somehow happy. Have we ever been so free of choices? The past is wiped out, all that matters is now. The present and the future. And the future is this field of stones, and here we are. And, you know, you never really summon all of your strength until you know that there’s no way back, no way to go but onward.”

And so onward they went. But Michel’s sanguinity was sharply reduced when the second car collapsed into a hole that had been concealed by a kind of trapdoor arrangement of boulders. With some work they were able to open the front lock and pull out Kasei, Maya, Frank and Nadia. But there was no chance whatsoever of freeing the second car, they didn’t have the lift or the leverage. So they transferred all the supplies out of it, until the lead car was absolutely stuffed. And they moved on, eight of them and their supplies, all now in a single car.

Beyond the landslide, however, it got easier. They followed the canyon highway down into Melas Chasma, and found that the road had been built close to the south wall, and as Melas was such a broad canyon the flood had had room to spread out, and had bowed off some ways to the north. It still sounded like air miners were running at full capacity right outside their lock, but the road was well above and to the south of the flood, which was releasing veils of frost steam that filled the chasm, and obscured any views farther north.

So they proceeded without difficulty for a couple of nights, until they came to the Geneva Spur, which stuck out from the gigantic south wall nearly to the edge of the flood. Here the official road had swung out into what was now the course of the deluge, and they had to find a higher route. The rocky traverses they made around the lower slopes of the Spur were really difficult for the rover. Once they were nearly hung up on an obtruding rounded rock, and Maya shouted at Michel, accusing him of recklessness. She took over the driving while Michel and Kasei and Nadia went out in walkers. They jacked them off the rock, and then walked ahead to reconnoiter the route of the traverse.

Frank and Simon helped Maya look for obstructions as she drove. Sax continued to spend all his time at his screen. From time to time Frank would turn on the TV and run a search for signals, trying to piece together news from the occasional staticky voices the radio found in the jamming. On the very spine of the Geneva Spur, as they were crossing the absurdly thin concrete thread of the Transcanyon Highway, they were far enough out from the south wall to get some transmissions, something about it not becoming a global dust storm after all. And indeed the days were sometimes only hazy, rather than clotted with the dust. Sax claimed this as proof of the relative success of the dust-fixing strategies pursued since the Great Storm. No one responded to this. The haze that was in the air, Frank observed, seemed actually to help clarify weak radio signals. That was stochastic resonance, Sax said. The phenomenon was counterintuitive, and Frank questioned Sax closely for an explanation of it. When he understood, the room rang with his mirthless bray. “Maybe all the emigration was stochastic resonance, enhancing the weak signal of the revolution.”

“I don’t think it helps to make analogies between the physical and social worlds,” Sax said primly.

“Shut up, Sax. Go back to your virtual reality.”

Frank was still angry; bitterness sublimed from him like the frost steam off the flood. He snapped questions at Michel about the hidden colony, his curiosity bursting out two or three times a day. Ann was happy to think she would not be Hiroko when Frank first met her. Michel answered these accusing questions calmly, ignoring the sarcasm and the furious gleam in Frank’s eye. Maya’s attempts to cool Frank only increased his rage, but she kept at it. Ann was impressed at how persistent she was, how insensitive to Frank’s brusque rejections. It was a side of Maya that Ann had never seen before; Maya was usually the most volatile person around. But not now, not when the pressure was really on.

Eventually they rounded the Geneva Spur, and got back on the bench under the southern escarpment. The way east was often interrupted by landslides, but they always had room to veer left around them. Progress was good.

But then they came to the eastern end of Melas. Here the greatest chasm of them all narrowed, and dropped several hundred meters down into the two parallel canyons of Coprates, which were separated by a long narrow plateau. South Coprates dead-ended in a cliffy headwall some 250 kilometers away; North Coprates connected with the lower canyons farther east, and therefore was the one they wanted to take. North Coprates was the longest single segment of the Marineris system; Michel called it La Manche, and like the English Channel it narrowed as it progressed eastward, until at around 60 ° longitude it narrowed and reared into a gigantic gorge— sheer cliffs four kilometers high, facing each other across a gap only twenty-five kilometers across. Michel called this gorge the Dover Gate; apparently the cliff walls in this gap were whitish, or had been.

So they made their way down North Coprates, and the cliffs closed in on them more every day. The flood filled almost the whole width of the canyon floor, and its flow was so rapid that the ice on its surface had broken into small bergs, which flew off the lips of standing waves and crashed back into the cascade: a furious white-water rapid with the flow of a hundred Amazons, topped by icebergs. The canyon floor was being ripped away, torn free of its bed and rushing down in red jolts of water like massive pulses of rusty blood, as if the planet were bleeding to death. The noise was incredible, a roar so continuous and pervasive that it dulled thought, and made talk almost impossible; they had to shout everything at the top of their lungs, which quickly reduced them to communicating only the basic necessities.

But then there was a very basic necessity to shout about, for when they came to the Dover Gate they found that the canyon floor was almost completely covered by the flood. Their bench below the southern wall of the gorge was no more than two kilometers wide, and diminishing every minute. It seemed possible the whole bench might be torn away in a flash. Maya cried that it was too dangerous to go on, and argued for a retreat. If they circled around and drove up to the dead end of South Coprates, she shouted, and managed to climb to the plateau above, then they could drive past the pits of Coprates, and proceed onward to Aureum.

Michel shouted his insistence that they press forward, and get through the Gate on the bench. “If we hurry we can make it! We must try!” And when Maya continued to protest, he added forcefully, “The head of South Coprates is steep! The car would never get up it, it’s a cliff like these! And we don’t have the supplies to add so many extra days to our trip! We can’t go back!”

The insane roar of the flood was his only answer. They sat in the car, in their separate thoughts, separated by the roar as if by many kilometers of space. Ann found herself wishing the bench would slide from under them, or a piece of the south wall fall onto them, and put an end to their indecision, and to the awful, maddening noise.

They drove on. Frank and Maya and Simon and Nadia stood behind Michel and Kasei, watching them drive. Sax sat at his screen, stretching like a cat, staring myopically at the little picture of the deluge. The surface calmed for a moment, and froze over, and the explosive noise reduced to a violent low rumble. “It’s like the Grand Canyon on a kind of super-Himalayan scale,” Sax said, apparently to himself, although only Ann would be able to hear him. “The Kala Gandaki Gorge is about three kilometers deep, isn’t it? And Dhaulagiri and Annapurna only forty or fifty kilometers apart, I think. Fill that with a flood like . . .” He failed to recall any comparable flood. “I wonder what all that water was doing so high on the Tharsis Bulge.”