All day the professor from the Massachusetts Institute of Technology geology research laboratory had prowled the northwestern edge of the caldera, burying several seismometers in the warm pumice grit and collecting rock, ash and air samples. Finally, after so many months, it had been deemed safe to approach the caldera, but a wave of bad weather, poor visibility and difficult fueling logistics had delayed Cascades Volcano Observatory helicopter flights throughout the month of October. When the craft finally touched down and dropped her off, Liz wanted nothing more than to stay put at the crater’s edge, despite a galloping wind and scudding clouds threatening snow.
Liz’s vantage point was one no human being had ever encountered. Before her yawned a fathomless canyon she estimated to forty or more miles across to the south rim. A few yards beyond her boots, the earth plunged vertically 800 feet to a hideously steep slope of ruination that pitched down at a dizzying angle for another 1,000 feet. The walls and slopes below smoked, pumping out hundreds of wispy tendrils that played tag with one another and dodged the wind.
A mile to the east, a river of mountain water reached the edge of the new lost world and leapt out into nothing, falling in a gossamer strand to lose itself in the mists below. Regularly, light-colored caked layers of pumice, dark volcanic glass shards, ash and rock fragments broke loose from the unstable plateau or the walls of the caldera and plunged in dusty avalanche falls into the depths. With snow clouds scudding overhead, steam from the fissures rising, the falls and rock slides descending, it appeared to the scientist that the entire expanse before her was a living organism, as if she were microscopic and could witness busy biological processes at the cellular level.
The scientist imagined she could spade up the Grand Canyon in Arizona and heave it into the Yellowstone void. That national marvel, its candy cane-stripe beauty intact, would fall away and vanish into the ugly, tortured hellhole below. Once thrown down, the sandstone reds and mudstone yellows of the countless buttes of the canyon, would, over millennia, be smothered with upwelling magma and drowned in temporary great lakes until sometime, far into the future, the abyss would fill in with new basalt and rhyolite rock and the cycle would prime itself once again for another catastrophe hundreds of millennia hence.
Already the earth building had commenced, as much of the great magma ocean was still intact far below. On the eastern horizon, the unseen caldera floor glowed with crimson heat. Viscous magma was oozing up quietly somewhere on the edge of sight, building up small swelling lava domes deep within the sunken ruins of the landscape. The researcher reflected a bit on the processes already underway before her and the time scale necessary to complete a new caldera cycle. Human beings, she thought, if they were still parading about the planet, would be three times older as a distinct species the next time Yellowstone vanished in clouds of ash and hell fire.
Scanning the country, synthetic fabric flapping lustily in the breeze, Liz was grateful for the easterly coursing wind. The caldera was still outgassing a toxic gas stew from thousands of small fissures and would do so, presumably, for generations to come. Conducting studies on the inner flanks of volcanic craters the world over, scientists had learned to work around upwelling poisonous gases, but no one in the scientific community had a minute of experience working inside a newborn volcanic environment spanning 2,000 square miles and that was, in a some places, nearly a mile deep. The volume of gas seeping from the earth’s bowels was impossible to know, but Liz sensed that the atmosphere wafting over the eastern rim, fouled by prodigious outpouring of gases, must be perfectly lethal.
Nothing looked remotely familiar. There were no landmarks to gauge where she was within the former park. The Gallatin Range to the west was an indistinct undulating series of humps, its prominent folds and creases filled in by pyroclastic sheet flows.
After months analyzing seismic and ash sample data and weeks pouring over photography and ash fall depth measurements across the country, the CVO team she was with had developed a portrait of the true extent of the Yellowstone eruption and caldera collapse.
When the first images of the new crater were downloaded, vulcanologists and geologists the world over stood in awe of them. The chasm created by the sinking of Yellowstone’s terrain into the empty upper magma chamber covered an area nearly twenty percent larger than the known dimensions of the former Lava Creek caldera that encompassed half of the national park. Using early raw figures to determine the extent of the ejected material from the eruption, CVO scientists estimated that no less than 1,800 cubic miles and perhaps as much as 2,200 cubic miles of volcanic deposits, from rock bombs, to pumice, to ash and fine dust, had vented from gaping fissures and vents around the oval dimensions of the caldera. A quick set of calculations and the team determined that the volume of ejected material, if it had all fallen within the dimensions of the state of Wyoming, would have smothered the entire state under no less than fifteen feet of ash and debris.
The superheated pyroclastic clouds billowing from the exploding caldera reached as far as 400 miles from their origin, southwest to Salt Lake City, north far into Idaho and Montana, and southeast across the Great Divide to within striking distance of the western city limits of Denver. Inside the pyroclastic flow zones, there was little evidence that anything had survived the catastrophe.
The preliminary ashfall profiles were overwhelming. Surrounding the crater and encompassing an area the size of the state of Ohio, ash accumulations were catastrophic, amounting to hundreds of vertical feet in many regions. So much material was heaped up that the land remained hot, the upper layers of ash acting as a thermal blanket trapping the heat of the pyroclastic flows and the super dense ash falls well below the surface. Where Liz stood, snow melted on contact with the ash, so much heat was finding its way to the surface from buried hot deposits below.
Further out, up to 500 miles from the epicenter of the eruption, ash depths ranged from eight to a dozen feet. Twice as far away and primarily to the east, ash accumulated in some locales as deep as three, four and five feet. Pushed by the prevailing westerlies, ash up to a foot in depth fell as far to the east as Madison, Wisconsin and Springfield, Illinois. Accumulations of up to several inches brought choking dust to the streets of Chicago; Grand Rapids, Michigan; Terre Haute, Indiana and Memphis, Tennessee.
To the west and southwest, the regions fared better as winds aloft carried much of the ash burden away into the Great Plains and Midwest. But the pyroclastic clouds scorched most of Montana and Idaho and much of Washington State well west of Yakima city but east of the Cascade Range. The devil’s veil of death swept the living away in western Oregon, northeastern Nevada, Utah south to I-70, and in the northwestern quadrant of Colorado, from Grand Junction through to Denver and north to Ft. Collins. As for most of Wyoming, Liz couldn’t imagine anything larger than a bacterium surviving the blowtorch clouds.
Over the course of her career, Liz had met many of the monsters of geology, the remains of catastrophic eruptions that raged in the deep and not so distant past: seawater-flooded Toba caldera; Santorini, the villain that erased the Minoan culture; the little bad-tempered infant island known as Anak Krakatoa, hiding the wreckage of the famed Krakatoa explosion in the late 1800s, and beautiful Crater Lake, the placid liquid child of massive Mount Mazama, a Rainier-sized volcano that had disintegrated in a flash and incinerated an area the dimensions of West Virginia.