Volcanic explosivity index in the context of "1980 eruption of Mount St. Helens"

This is a list of volcanoes that have had large explosive eruptions during the Holocene (since about 11,650 years Before Present), with a volcanic explosivity index (VEI) of 5 or higher, or a plume height of at least 30 km. To date, there have been no eruptions with a confirmed VEI of 8 in the Holocene; and only a few VEI-7 eruptions are thought to have occurred during this time: the most recent was the 1815 eruption of Mount Tambora.

In April 1815, Mount Tambora, a volcano on the island of Sumbawa in present-day Indonesia (then part of the Dutch East Indies), erupted in what is now considered the most powerful volcanic eruption in recorded human history. This eruption, with a volcanic explosivity index (VEI) of 7, ejected 37–45 km (8.9–10.8 cubic miles) of dense-rock equivalent (DRE) material into the atmosphere, and was the most recent confirmed VEI-7 eruption.

Although the Mount Tambora eruption reached a violent climax on 10 April 1815, increased steaming and small phreatic eruptions occurred during the next six months to three years. The ash from the eruption column dispersed around the world and lowered global temperatures in an event sometimes known as the Year Without a Summer in 1816. This brief period of significant climate change triggered extreme weather and harvest failures in many areas around the world. Several climate forcings coincided and interacted in a systematic manner that has not been observed after any other large volcanic eruption since the early Stone Age.

Between 20 May and 21 October 1883, the volcanic island of Krakatau, located in the Sunda Strait, erupted. On 27 August, the island had its most significant eruption, which destroyed over 70% of the island and its surrounding archipelago, afterwards collapsing itself into a caldera. The 27 August eruption had an estimated Volcanic Explosivity Index (VEI) of 6, and is one of the deadliest and most destructive volcanic events in recorded history; the third explosion of that day, which occurred at 10:02 am, remains the loudest known sound in history.

The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away. The acoustic pressure wave circled the globe more than three times. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were felt worldwide in the days and weeks after the volcano's eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption.

Christopher G. Newhall is a volcanologist, formerly with the U.S. Geological Survey and the Earth Observatory of Singapore. He is the co-creator of the Volcanic explosivity index and specializes in volcanic prediction.

A supervolcano is a volcano that has had an eruption with a volcanic explosivity index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than 1,000 cubic kilometers (240 cubic miles).

Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure and ruptures. This can occur at hotspots (for example, Yellowstone Caldera) or at subduction zones (for example, Toba).

Mount Tambora, or Tomboro, is an active stratovolcano in West Nusa Tenggara, Indonesia. Located on Sumbawa in the Lesser Sunda Islands, volcanism is the result of subduction zones. The 1815 eruption was the largest in recorded history, erupting up to 150 cubic kilometers of volcanic material, making it a VEI-7 on the Volcanic explosivity index. This caused the summer of 1816 to become known as the "Year Without a Summer" due to global cooling from the eruption.

The Phlegraean Fields (Italian: Campi Flegrei, Italian: [ˈkampi fleˈɡrɛi]; Neapolitan: Campe Flegree) is a large volcanic caldera west of Naples, Italy. The Neapolitan Yellow Tuff eruption (about 12ka BP) produced just 50 cubic kilometers. It is, however, one of relatively few volcanoes large enough to form a caldera. It is part of the Campanian volcanic arc, which includes Mount Vesuvius, about 9 km (6 miles) east of Naples. The Phlegraean Fields is monitored by the Vesuvius Observatory. Part of the city of Naples is built over it.The Phlegraean Fields' largest known eruptions have an estimated volcanic explosivity index (VEI) of 7. It is often called a supervolcano in popular media, although the accepted definition for that term is a volcano that has had an eruption with a VEI of 8, the highest level.

The area of the caldera consists of 24 craters and volcanic edifices. Most of them lie under the Gulf of Naples. There are effusive gaseous manifestations in the Solfatara crater, which was believed in ancient Rome to be the home of Vulcan, the god of fire. The area features bradyseismic phenomena, which are most evident at the Macellum of Pozzuoli, misidentified by 18th-century excavators as a temple of Serapis: bands of boreholes left by marine molluscs on marble columns show that the level of the site in relation to sea level has varied. Hydrothermal activity can still be observed at Lucrino, Agnano and the town of Pozzuoli.

Katla (Icelandic pronunciation: [ˈkʰahtla] ) is an active subglacial volcano in southern Iceland. This volcano has been very active historically with at least twenty documented major eruptions since 2920 BC. In its recent history though, Katla has been less active as the last major eruption occurred in 1918. These eruptions have had a Volcanic Explosivity Index (VEI) of between 4 and 5 on a scale of 0 to 8. In comparison, the Eyjafjallajökull 2010 eruption had a VEI of 4. Larger VEI-5 eruptions are comparable to Mount St. Helens 1980 eruption. These eruptions have produced very large glacial outburst floods. Several smaller (minor) events measuring VEI-1 and below have occurred since.

Katla is one of the largest volcanic sources of carbon dioxide (CO₂) on Earth, accounting for up to 4% of total global volcanic carbon dioxide emissions.