Biggest recorded

Mount Tambora, which produced one of the largest eruptions in recorded history on April 10, 1815, as seen in an image taken by an astronaut. (Image credit: NASA)

The biggest volcanic eruption ever recorded by humans was the explosion of Mount Tambora on Sumbawa Island, Indonesia, in 1815. It ranked a 7 (or "super-colossal") on the Volcanic Explosivity Index, the second-highest rating in the index.

Long-lasting effects

The eruption of Indonesia's Mount Pinatubo in 1991. (Image credit: U.S. Department of Interior, U.S. Geological Survey.)

The gas and other particles spewed high into the atmosphere during the 1991 eruption of Mount Pinatubo reduced global temperatures by about 0.9 degrees Fahrenheit (0.5 degrees Celsius) during the following year.

Lots of ash

Here, steam rises from fumaroles on the caldera floor of Pinatubo, after the June 15 eruption and caldera collapse, as viewed from the north on Oct. 4, 1991. The outer flanks of the caldera are stripped of vegetation and covered with ash. (Image credit: Chris Newhall/USGS.)

The 1991 eruption of Mount Pinatubo ejected more than 1 cubic mile (5 cubic kilometers) of material into the air and created a column of ash that rose 22 miles (35 km) in the atmosphere.

Big blast

Ash covers houses after the 1912 blast. (Image credit: U.S. Department of Interior, U.S. Geological Survey.)

The largest volcanic blast of the 20th century was the eruption of Novarupta one of a chain of volcanoes on the Alaska Peninsula, part of the Pacific Ring of Fire in 1912. It was a 6 (out of a possible 8) on the Volcanic Explosivity Index.

Continuous erupting

Kilauea's current eruption is still going strong after 29 years. (Image credit: USGS/HVO.)

Hawaii's Kilauea volcano, one of the most active on Earth, has been erupting continuously for more than 29 years, beginning Jan. 3, 1983.

Deadly eruption

Explosions much larger than this one in 2008 were more common on Mount Kilauea than previously though. (Image credit: USGS)

Kilauea erupted 200 years ago, sending speeding lava flows down its peaks and killing more than 400 people, including Hawaiian warriors. It was the deadliest volcanic eruption on record in what is now the United States.

Far-reaching effect

Lava steaming as it hits the ocean. (Image credit: USGS Hawaii Volcano Observatory)

Kilauea means "spewing" or "much spreading" in Hawaiian.

New activity

The Earth Observing-1 (EO-1) satellite snapped this photo on June 12. The red color indicates heat, either from liquid or recently hardened lava still hot enough to glow. (Image credit: NASA)

More than 90 percent of Kilauea's surface is covered by lava less than 1,100 years old.

Stratovolcanoes

The snow-capped Ngauruhoe cone of New Zealand's Mount Tongariro volcano is one of the youngest and more active parts of the volcano. (Image credit: Don Swanson, 1984 (U.S. Geological Survey))

Stratovolcanoes are tall, steep, conical structures that periodically erupt explosively and are commonly found where one of Earth's plates is subducting below another, producing magma along a particular zone.

Large mountains

The island of Hawaii is home to four volcanoes monitored by volcanologists: Mauna Loa, Hualalai, Kilauea, and Mauna Kea. (Image credit: NASA.)

The Hawaiian shield volcanoes are the largest mountains on Earth. The total height of Mauna Kea, below and above sea level, is 33,500 feet (10,210 meters), making it taller than even Mount Everest.

Largest volcanoes

(Image credit: NASA)

The largest volcanoes on Earth are shield volcanoes, which have broad, gentle slopes built by fluid basalt lavas.