Volcano Eruption, Shield Volcano, Pyroclastic Flow, Italy, Japan, Iceland

Location: 40.8N, 14.4E
Elevation: 1,281 m (4,200 feet)


Today two million people live in the immediate vicinity of Mount Vesuvius. This mountain has erupted more than 50 times since the eruption in 79 A.D., when it buried Pompeii and its sister city, Herculaneum. After Pompeii was buried and lost to history, the volcano continued to erupt every 100 years until about 1037 A.D., when it entered a 600 year period of quiescence.

The 79 A.D. eruption of Vesuvius was the first volcanic eruption ever to be described in detail. From 30km (18 miles) west of the volcano, Pliny the Younger, witnessed the eruption and later recorded his observations in two letters. He described the earthquakes before the eruption, the eruption column, air fall, the effects of the eruption on people, pyroclastic flows, and even tsunami. Volcanologists now use the term "plinian" to refer to sustained explosive eruptions which generate high-altitude eruption columns and blanket large areas with ash. It is estimated that at times during the eruption the column of ash was 32 km (20 miles) tall. About 4 cubic kilometers (1 cubic mile ) of ash was erupted in about 19 hours. Volcanoes by Peter Francis contains several direct passages from Pliny the Younger and describes the archeology of Pompeii and Herculaneum. Copyrighted photograph of a street in Pompeii by Robert Decker, 1971. Vesuvius is in the background.

Mudflows and lava flows from the eruption in 1631 killed 3,500 people. Studies of past eruptions and their deposits continue. These studies help volcanologists understand the hazards associated with future eruptions. The population density in some areas of high risk is 20,000 to 30,000 per square km (7,723 to 11,584 miles per square km). About 3 million people could be seriously affected by future eruptions. In the first 15 minutes of a medium- to large-scale eruption an area with a 7 km (4 mile) radius of the volcano could be destroyed (Dobran and others, 1994). About 1 million people live and work in this area.

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Hokkaido-Komagatake Volcano, or Komagatake (Hokkaido), is located 30 km (18.64 miles) north of Hakodate City with population of 320,000. Large-scale pumice-flow eruptions had occurred several times from craters within the caldera, including historical 3 major eruptions; 1640, 1856, and 1929.

In the 1640 eruption, the summit part collapsed and the avalanche entered into sea, resulting in the generation of tsunami, killing 700 people. In 1929, the volcano eruption produced 0.38 cubic kilometers (0.1 cubic miles) of ash falls and 0.14 cubic kilometers (0.03 cubic miles) of pumice flows in one day, killing 2 and injuring 4.


Izu-Oshima is a volcano island about 30 km (19 miles) east of the Izu Peninsula. The island is about 15 km (9.3 miles) long, elongated in the NW-SE direction. The elevation of the summit, Miharayama, which is the post-caldera central cone, is 764 m a.s.l. The Izu-Oshima volcano itself is younger than 40 thousand years ago. The younger stages of its history started around 1500 year BP after the formation of the summit caldera with 3-4 km diameter. More than 70 parasitic cones and the central cone arranged in the zone as narrow as 2 km wide, trending in NW-SE. The detailed and thoughtful volcanological knowledge about this island was acquired by the late Prof. Kazuaki Nakamura, who passed away after seeing the 1986 eruption with his own eyes. One of his works shows clearly that relatively large eruptions had occururred each 150 years at this volcano, although small eruptions, including the 1986 eruption, had also occurred each 35 year recently.

Eruption started at the central crater of the Miharayama at 17:25 (JST), November 15, 1986, making lava fountains and lava lake in the crater. Lava began to overflow and flow down the slope of the Miharayama on November 18, and reached and spread on the caldera floor. The activity in the central crater had declined once until 20 November. The activity suddenly resumed with large fissure eruptions on the caldera floor at 16:15, November 21. The lava fountain was as high as 1,600 m (5249 feet). Large amounts of scoria deposited within the island. The fissure reached the length of 1 km (.62 miles). The central crater was re-activated soon after the fissure eruptions. At 17:45, eruption also started outside caldera. A lava flow descended toward the town but stopped before reaching the residential area. The activity had declined after the final bursting at 09:43, November 23. Total volume of products of this eruption was estimated as 7,900 ton.

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Location: 7.32S, 107.73E
Elevation: 2665m (8700 ft)


Papandayan is a stratovolcano which is found in a row of volcanoes. It has very distinctive yellow crater walls due to coloring by sulfur. The crater is surrounded by forest and extends to the northwest by a long, steep chasm. This chasm becomes a river channel at the foot of the mountain.

The highest part of the crater floor lies to the southeast. It is ~6600 feet (2000 m) high and sits ~800 feet (240 m) below the crater rim. The floor of this crater contains sulfurous pools of standing water, fumaroles, solfataras, mud volcanoes and hot springs. All this minor volcanic activity makes it quite noisy on the crater floor. A river which flows across the floor of the crater begins as a clear stream in the forest but quickly becomes heated and filled with sulfuric acid as it flows across the floor. The mud volcanoes on the floor of the crater are normally 2-4 feet (0.6-1.2 m) high and explode with great force. They eject hot, muddy water every 20-25 seconds.

Bardarbunga Volcano
Location: 64.63N, 17.53W
Elevation 2000 m(6560 ft )
Type: Stratovolcano

Grimsvotn Volcano
Location: 64.42N, 17.33W
Elevation 1725 m (5658 ft)
Type: Caldera

The Vatnajökull glacier in Europe is a temperate glacier covering about 8300 km² (3205 sq. miles) in the SE part of Iceland. Volcanic fissure systems of the Mid- Atlantic Ridge plate boundary are partly covered by the western part of the ice sheet. Two major volcanic centers lie beneath the ice, the Bardarbunga volcanic centre and the Grimsvötn volcanic centre both with large subglacial caldera depressions. The Bardarbunga centre is a part of a fissure system extending over 100 km (62 miles) to the south and some 50 km (31 miles) to the north of the glacier. The last eruption within the Bardarbunga centre occurred in 1910, but eruptions on the fissure system have occurred in 871 AD, 1477 AD, and 1862 AD, all producing substantial amounts of lava.

The Grimsvötn centre is the more active of the two with an eruption frequency during past centuries close to one eruption per decade. The last eruption occurred in 1983. As Bardarbunga the Grimsvötn centre is a part of a fissure system which includes the Laki fissure, which in 1783 produced about 12-14 km³ (2.9-3.3 cubic miles) of basaltic lava. Within the ice filled Grimsvötn caldera intense geothermal activity continuously melts the ice to form a subglacial lake, which at intervals of 5 to 10 years is emptied along subglacial channels to create large floods (jökulhlaup) on the sandur plain, Skeidararsandur, on the Icelandic south coast. The lake was last emptied in 1996 and the waterlevel is presently low.

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Location:36.40°N, 138.53°E
Elevation: 2,560 m (8,399 ft)


Asama, Honshu's most active volcano, is located at the junction of the Izu-Marianas and NE Japan arcs and has a historical record dating back more than 1,300 years.

Volcano: Deadliest Eruptions