Bezymianny

The Novy lava dome at Kamchatka's Bezymianny volcano has been growing since 1956 within a large horseshoe-shaped crater. The 1.8 x 2.5 km crater formed during the catastrophic 1956 eruption when the summit of the volcano collapsed, producing a debris avalanche and lateral blast that swept to the east. This 1980's view from the SW shows the outer flanks of the pre-1956 volcano in the foreground. The lava dome has subsequently grown to the height of the crater rim.

Bogoslof

Lava dome remnants from three historical eruptions can be seen in this NW-looking aerial view of Bogoslof Island in the Aleutians. The pinnacle on the left is Castle Rock, also referred to as Old Bogoslof, a remnant of a 1796 lava dome. The circular, flat-topped area to its right is a remnant of a 1927 lava dome. The most recent eruption of Bososlof, in 1992, produced the light-colored conical lava dome forming the tip of the island at upper right. Frequent eruptions and vigorous wave erosion have greatly modified the island in historical time.

Bogoslof

An aerial view shows the 1992 lava dome of Bogoslof Island, the summit of a largely submarine stratovolcano located in the Bering Sea 50 km behind the main Aleutian arc. The 1992 lava dome grew to a height of 100 m in July at the northern tip of Bogoslof Island. The island is about 1.5 x 0.6 km wide, and due to its frequent eruptive activity and energetic wave action, has changed shape dramatically since first mapped in the late 1700's.

Chichon, El

A forested lava dome, seen here from the east in 1974, filled the crater of Mexico's El Chichon volcano and formed the volcano's high point prior to a major eruption in 1982. The low ridge cutting across the middle of the photo is the rim of the pre-1982 crater. Powerful explosive eruptions in March and April 1982 removed the lava dome and replaced it with a 1-km-wide crater.

Lassen Volcanic Center

Chaos Crags in the foreground and Lassen Peak in the background are large lava dome complexes in the southern Cascade Range. Chaos Crags consists of a group of five overlapping dacitic lava domes that were erupted a little over 1000 years ago. Lassen Peak was formed about 25,000 years ago, but last erupted during 1914-17.

Merapi

Incandescent rockfalls accompanying slow growth of the summit lava dome descend from beneath a cloudcap covering the summit of Merapi volcano in this 1993 nighttime view. Periodic collapse of Merapi's lava dome has produced pyroclastic flows down the western and southern flanks that have devastated populated areas and agricultural lands.

Merapi

A blocky lava dome produced during eruptions from 1972 to 1985, lies within the summit crater of Merapi volcano in central Java. A small spine appears on the right in this July 4, 1986 photo, which was taken during a period of inactivity prior to destruction of the dome on October 10, 1986. Merapi's historical eruptions have been characterized by repeated growth and collapse of the summit lava dome, periodically producing pyroclastic flows that have affected populated areas on the volcano's western and southern flanks.

Pululagua

Cerro Sincholagua (left) and Loma la Marca (right) are the southernmost of a group of lava domes pre-dating the formation of Pululagua's caldera. Seen here from the equator to their south, they are part of a chain of lava domes that were constructed on a roughly N-S line east of the caldera. Cerro Sincholagua forms the highest peak of 3356-m Pululagua volcano.

Pululagua

Pululagua is a relatively low, forested volcano immediately north of the equator, 27 km north of Quito. Loma Pondona (left) and the lower Rumiloma (right center) are two of a group of lava domes that partially fill a 3-km-wide summit caldera. They are seen here from the SE caldera rim. The caldera was formed during the latest dated eruption of Pululagua about 2400 years ago. Pululagua produced large explosive eruptions accompanied by pyroclastic flows during the late Pleistocene and Holocene.

Redoubt

This oblique view from the north shows the final lava dome of the 1989-90 eruption of Alaska's Redoubt Volcano as it appeared approximately one year after the end of the eruption. The dome measures approximately 350-400 m across and represents an estimated 10 million cubic meters of material. Snow is accumulating on the cooling lava blocks although some hydrothermal activity continues to produce intermittent steam plumes. Periodic lava dome growth during the eruption was punctuated by strong explosions that destroyed earlier lava domes.

Santa Maria

Incandescent areas are visible at the top of the growing Santiaguito lava dome in Guatemala. Rockfalls from the dome produce a glowing trail down its flanks. The Santiaguito dome began growing in 1922 in a large crater formed on the SW flank of Santa Maria volcano during a powerful explosive eruption in 1902. Dome growth has been continuous since 1922 and has produced a composite, elongated dome more than 3 km long. This photo of El Brujo, the westernmost vent, was taken in 1967.

Santa Maria

A small blocky lava dome fills the crater of Caliente vent on the Santiaguito lava dome of Guatemala's Santa Maria volcano on July 18, 1969. This was near the beginning of a period of renewed activity at the Caliente vent, on the eastern side of Santiaguito. Growth of the composite Santiaguito lava dome has been occurring since 1922.

Soufriere Hills

Scientists from the Montserrat Volcano Observatory make monitoring measurements in February 1997 as small rockfalls descend the flanks of the summit lava dome. Castle Peak lava dome, constructed during the previous eruption of Soufriere Hills during the 17th century, had collapsed three days prior to the date of this photograph, which was taken from the Tar River Estate house, 2 km NE of the dome. Periodic collapse of the growing lava dome produced pyroclastic flows that in some cases reached to the sea.

Soufriere St. Vincent

A blocky lava dome, 130 m high and more than 840 m wide filled much of the crater floor of Soufrière St. Vincent volcano during the 1979 eruption. Dome growth began in May, after a series of powerful explosive eruptions April 13-15, and continued until October. Steam continues to rise from the dome in this 1983 photo from the SW crater rim.

St. Helens

Incandescence is visible in fractures in a growing lava dome in the crater of Mount St. Helens on October 18, 1980. Several earlier lava domes formed after May 18, 1980 had been removed by explosive eruptions. This photo shows the beginning stages of the lava dome that grew incrementally until the end of the eruption in October 1986.

St. Helens

Lava domes are formed by the extrusion of viscous, silica-rich lava that accumulates above the volcanic vent. This steaming lava dome partially fills the crater of Mount St. Helens in April 1983. Dome extrusion often follows explosive eruptions, which decrease the gas content of the remaining magma. Dome growth, however, is commonly accompanied by explosive activity and pyroclastic flows. Lava domes can form within the summit craters of volcanoes or on their flanks. They may build solitary, domical masses, or a complex of overlapping domes.

Unzen

This closeup view on May 20, 1991, shows the first lava extrusion of the 1990-95 eruption of Unzen volcano in Japan. The dome was extruded in the Jigoku-ato crater, which was formed by an explosion on the first day of the eruption, November 17, 1990. By May 23 the dome reached a height of 44 m and had a diameter of 110 m. It then began spilling over the east crater rim (upper right). Periodic collapse of the oversteepend front of the dome produced pyroclastic flows that traveled progressively farther down the Mizunashi valley.

Unzen

The 1990-95 eruption of Unzen volcano, on the southern Japanese island of Kyushu, produced a lava dome at the summit of Fugen-dake. The rising sun colors the dome, seen here from the NE on February 2, 1995, near the end of the eruption. By this time the dome had grown to a height of 1500 m, about 200 m above the pre-eruption surface. Periodic collapse of the growing lava dome had produced pyroclastic flows that devastated areas on the SE and NE flanks. Thousands of persons living below the dome faced long-term evacuation.