Survey of ocean floor reveals long history, from a geological fault to the wreckage of the Lusitania.

About 800 million years ago, East Antarctica, now one of the coldest regions on Earth, abutted what is now Death Valley, Calif., one of the hottest.

Cruising in an icebreaker to the top of the world, scientists identified the aftermath of an event once thought impossible: a violent volcanic eruption on the deep-sea floor.

New fossils of an ancient, four-limbed creature help fill in the blanks of the evolutionary transition between fish and the first land-adapted vertebrates.

New evidence suggests that the South American mountain chain shot up 2.5 kilometers in a geological blink of an eye.

Asteroid or comet blamed for Siberian blast of 1908

An image of a pyroclastic flow, one of the quickest and deadliest phenomena related to volcanic eruptions, has finally been caught by a satellite. These ground-hugging avalanches of hot ash and rocks can sweep down a volcano’s slopes at more than 100 kilometers per hour. They last no more than a few minutes, says Avijit Gupta, a geomorphologist at the University of Leeds in England. Luckily, he notes, the ground-gazing IKONOS satellite was passing over Indonesia’s Mount Merapi while it was erupting on June 16, 2006. Although scientists previously have tried to detect pyroclastic fl...

A new supercomputer simulation of the large quake that struck central China earlier this month could help researchers estimate the size of the ground motions experienced in areas that didn’t have seismic instruments.