Volcano 101 | National Geographic

What are Volcanoes?00:00:01

Volcanoes are openings or vents to the hot interior of the planet. There are about 1,500 active volcanoes worldwide, with nearly 90% located in the Ring of Fire around the Pacific Ocean.

Formation of Volcanoes00:00:39

Volcanoes often form where tectonic plates interact. Friction from shifting plates melts the Earth's crust, liquefying rock into magma, which then erupts through rifts.

Types of Lava and Volcanoes00:00:58

Once magma escapes, it's called lava. Runny lava forms gentle shield volcanoes, while thick, sticky lava builds steeper composite volcanoes that can erupt violently. Hawaii's Kilauea is a continuously erupting shield volcano formed over a hotspot.

Volcanic Hazards00:02:04

Living near volcanoes can be hazardous. The 79 AD eruption of Mount Vesuvius buried Pompeii with superheated ash, poisonous gas, and rocks in a deadly pyroclastic flow, claiming 2,000 lives.

Benefits of Volcanoes00:02:30

Despite their dangers, volcanoes have created 80% of Earth's surface and contributed to the air we breathe. They also produce rich soil for farming, and their subsurface heat can be harnessed for geothermal energy.