POPOCATÉPETL VOLCANO, Mexico — In the predawn darkness, a team of scientists climbs the slope of Mexico's Popocatépetl volcano, one of the world's most active and whose eruption could affect millions of people. Its mission: figure out what is happening ...

When you think of the United States, images of sprawling cities and vast landscapes might come to mind, but not the hidden and ever-present geological threat: volcanoes. While you might associate volcanic eruptions with distant lands, numerous active ...

On June 11, the 1,000-plus-foot lava blasts of Kīlauea, one of the world’s most active volcanoes, nearly lured one visitor to his death. A 30-year-old Boston man fell 30 feet from a steep cliff after venturing off a trail to get a closer look at the ...

Hidden beneath the placid surface of a Siberian lake, a robot has mapped a landscape that looks more like an alien seabed than a freshwater basin. By tracing plumes of gas and reshaped sediments, researchers have uncovered active mud volcanoes and a fault ...

Some cities just happen to exist uncomfortably close to volcanoes. That kind of proximity affects routines, infrastructure, and how people think about risk. Scientists surveil shifting ground and rising gases, while residents live with the possibility that ...

POPOCATÉPETL VOLCANO, Mexico -- In the predawn darkness, a team of scientists climbs the slope of Mexico's Popocatépetl volcano, one of the world's most active and whose eruption could affect millions of people. Its mission: figure out what is happening ...