Depression at the mouth of a volcano

Usage examples of caldera.

Turning around from time to time, to keep her bearings, she noticed the wall by the evesmol resembled a curved sheet of window glass, vividly displaying the outside reddish bronze escarpment of the caldera.

Inside the Depression, there are hundreds of old calderas and extinct geysers.

On these great playas and on the frost-caked walls of channels, cliffs, and calderas, transplanted lichen had clung and leapt into devouring life.

Olympus itself, rising right at the edge of the Tethys ocean, was staggering in its immensity, an endless cone of icefields rising to an impossibly green summit with a series of blue lakes in its caldera.

Mars, especially these summer mornings, you get a fine view from the Rimshot Cafe, eastward from the lip of the caldera, fine white slopes of the old shield volcano tumbling gradually away, superimposed against the gray-green plains below, Jovis Tholis an isolated red pimple in the midst of all that, then the purple majesty of Ascraeus Mons, trailing wings of backlit cloud, peeking over the horizon.

Once, for a brief time, the caldera had been a cratered ice lake, a vast year-round equatorial winter playground for the new Martians, but the mold and the lichens had taken hold there as well, and turned the caldera a grim greenish-black.

In the shadow of the caldera rim he saw a great crescent of dappled movement punctuated by hundreds of tiny winking fires where whole spitted camels and sheep were roasting.

A massive volcanic caldera rearing up into the biosphere, Elysium formed a huge natural amphitheater .

She stopped talking a moment, feeling battered by shuddering waves of hope and yearning, fear and excitement coming at her from the crowd, it was like wingriding over the caldera of an active volcano.

The three immense volcanoes of the Tharsis Bulge and the even bigger caldera of Olympus Mons seemed to be staring down at him like the four monstrous wide round eyes of a demon, staring balefully.

At its top is a crater, a caldera, barely wide enough to swallow Delhi or Calcutta.

They carried on their way around the caldera, a progress slowed by more wess'har stopping Aras to say ho w significant, how wonderful, it was to see him.

So they'd put a landing craft smack in the center of the caldera to look for life -- and they'd found it: strange forms of cyanobacteria, eating CO2 and nitrogen, water and sunlight, and slowly replicating as they'd done for the past billion-odd years.

There was even talk of covering some of the big calderas, and of running cable cars between the three prince volcanoes, or bridging the narrows south of Elysium.

Looking down into it gave them a new perspective—a proper shape to the caldera and its circular embayments, a sudden drop to a heretofore hidden floor, a thousand meters below.