Near the summit of Mount Tongariro in New Zealand's volcanic region, the Emerald Lakes take their color partly from dissolved minerals.

CRATER LAKE, OREGON

About 6,850 years ago , Mount Mazama blew its top in a massive explosion that rained ash, dust and lava. Following the explosion, Mazama's top collapsed to form the caldera you see in this shot, taken in 2006 from the International Space Station....[More]

CRATER LAKE, OREGON

About 6,850 years ago, Mount Mazama blew its top in a massive explosion that rained ash, dust and lava. Following the explosion, Mazama's top collapsed to form the caldera you see in this shot, taken in 2006 from the International Space Station. The caldera later filled with water and became what is now one of the world's largest freshwater lakes with the deepest average depth of any in North America.  [Less] [Link to this slide]

One of the world's most active volcanoes, Kilauea harbors a summit caldera that is covered in fresh lava flows in this satellite image.

SANTA ANA VOLCANO, EL SALVADOR

Look closely to spot two lakes in this colorized satellite image. The first, a crater lake, appears as a tiny blue area at the summit of the Santa Ana volcano, the highest point in El Salvador....[More]

SANTA ANA VOLCANO, EL SALVADOR

Look closely to spot two lakes in this colorized satellite image. The first, a crater lake, appears as a tiny blue area at the summit of the Santa Ana volcano, the highest point in El Salvador. The second, just behind and to the right of Santa Ana, is a much larger caldera lake inside the Coatepeque Caldera. The red coloring indicates vegetation on the slopes of the volcanoes.  [Less] [Link to this slide]

CRATER LAKE, RUAPEHU, NEW ZEALAND

The pale blue dot in the center of this image marks Crater Lake atop New Zealand's Mount Ruapehu, one of the most thoroughly studied and monitored volcanic lakes in the world....[More]

CRATER LAKE, RUAPEHU, NEW ZEALAND

The pale blue dot in the center of this image marks Crater Lake atop New Zealand's Mount Ruapehu, one of the most thoroughly studied and monitored volcanic lakes in the world. "Eruptions through the lake occur relatively frequently, changing the physical dimensions of the lake and posing a constant threat to human activities in the area," scientists at the University of California, Davis, wrote.  [Less] [Link to this slide]