Mount Baker stratovolcano in the North Cascades rises 1500 m above a dissected basement complex of metamorphic and sedimentary rocks, exposed at Dock Butte in the foreground. On the left skyline is the glacially eroded core of the Pleistocene Black Buttes stratovolcano, a predecessor to Mount Baker. From left to right, the Deming, Easton, Squock, Talum, Boulder, and Park Glaciers drape the volcano's flanks.
A steam plume blows from the summit of México's Colima volcano in this 1992 view from the WSW with snow-capped Nevado de Colima to the left. Colima, also known as Fuego de Colima, is one of North America's most active volcanoes. Frequent eruptions have been recorded since the 16th century. A complex succession of eruptions that has been dominated during the past century by lava effusion associated with lava dome growth has also produced explosive eruptions of varying magnitude and frequent pyroclastic flows.
Fuego (left) and Acatenango are two of several paired volcanoes in Guatemala. Southward-younging volcanism constructed these two large stratovolcanoes and flank vents perpendicular to the trend of the Guatemalan volcanic front. The chemistry of lavas also varied progressively from dominantly andesitic at Acatenango to increasingly basaltic at Fuego. Activity from the Pleistocene-Holocene Acatenango has continued only sporadically into historical time, but Fuego is one of the most active volcanoes in Guatemala, with about 60 historical eruptions.
Early November snowfall at Haku-san accentuates the volcano's name, which means White Mountain. Eruptions at multiple vents along a roughly N-S line give the complex stratovolcano an elongated profile; the volcano is viewed here from the west. Holocene eruptions have consisted of phreatic or phreatomagmatic explosions from several summit craters. Historical eruptions were recorded over almost a thousand-year period until the 17th century.
Seen from the SW, Iwate stratovolcano on Japan's northern island of Honshu, has an elongated profile. The extensively dissected Onogajo volcano forms the older, western part of Iwate and is truncated by the 1.8 x 3 km Nishi-Iwate caldera. The smoother slopes at the right are formed by ejecta from the younger Yakushi-dake cone, which was constructed on the eastern rim of the caldera.
Sharp-topped Mount Jefferson stratovolcano has been inactive since the late Pleistocene and shows the effect of extensive dissection by glacial erosion. The Jefferson Park Glacier on the north flank in the foreground and the Whitewater Glacier on the east flank are the two largest on Jefferson.
Kamchatka's two highest volcanoes rise above a sea of clouds. Their greatly differing morphologies reflect contrasting geologic histories. Construction of extensively eroded Kamen volcano (left) took place during the Pleistocene. It has been relatively inactive since. Its eastern (right) side was removed by a massive landslide about 1200-1300 years ago, leaving the steep escarpment. Symmetrical Kliuchevskoi, in contrast, is one of Kamchatka's youngest and most active volcanoes, growing to 4835 m in the past 6000 years.
Symmetrical Kronotsky stratovolcano, one of Kamchatka's most scenic volcanoes, lies between the Pacific Ocean and Lake Kronotsky, Kamchatka's largest lake. The flanks of the massive 3528-m-high volcano, one of the largest in Kamchatka, are dissected by radial valleys up to 200-m deep. Weak phreatic eruptions took place during the 20th century. Kronotsky is seen here from the SW, with the caldera rim of neighboring Krasheninnikov volcano in the foreground.
Mayon volcano in the Philippines is one of Earth's best examples of a classic, conical stratovolcano. Its symmetrical morphology is the exception rather than the rule, and is the result of eruptions that are restricted to a single central conduit at the summit of the volcano. Eruptions are frequent enough at Mayon, the most active volcano in the Philippines, to overcome erosive forces that quickly modify the slopes of most volcanoes.
Mombacho is a stratovolcano on the shores of Lake Nicaragua that has undergone edifice collapse on several occasions. Two horseshoe-shaped craters cut the summit on the NE and south flanks, modifying the profile of the volcano. The NE-flank scarp, whose NE wall forms the left skyline, was the source of a large debris avalanche that produced an arcuate peninsula and the Las Isletas chain of islands in Lake Nicaragua. The only reported historical activity was in 1570, when a debris avalanche destroyed a village on the south side of the volcano.
Las Pilas stratovolcano, seen here from the south, is the most prominent feature of Nicaragua's Las Pilas volcanic complex. Las Pilas barely exceeds 1000 m in elevation, but it towers 900 m above its base in the Nicaraguan depression only a few hundred m above sea level. Its broad 1088-m-high summit is cut by a 700-m-wide crater and by a N-S fissure formed during an eruption in 1952. There were no previously documented eruptions of this volcano since the arrival of Spanish explorers in the 1520s.
The snow-capped peak of Mexico's Popocatepetl stratovolcano rises above Tlamacas to its north. Faint steam ascends from a deep elliptical summit crater, whose NE rim is 170 m below the summit. The sharp peak below the horizon at the right is Ventorrillo, the summit of the eroded Nexpayantla volcano, a predecessor to Popocatepetl. Its steep cliffs expose the stratified, layered interior of a stratovolcano.
Stratovolcanoes, also referred to as composite volcanoes, are constructed of sequential layers of resistant lava flows and fragmental material produced by pyroclastic eruptions. An aerial view of the glacially dissected SW flank of Mount Rainier shows the layered interior of a stratovolcano. Snow cover, which preferentially clings to less-steep layers of fragmental material, accentuates the stratified character of this composite volcano.
The interior of a stratovolcano is dramatically revealed in a 1-km wide crater created on the SW flank of Guatemala's Santa Maria volcano during an eruption in 1902. The 1200-m-high wall exposes thin, light-colored lava flows that are interbedded with deposits of fragmental material produced during growth of the volcano. The 1902 eruption, the first in historical time at Santa Maria, was one of the world's largest during the 20th century.
Snow-capped Ngauruhoe is a small 2291-m-high stratovolcano that was constructed during the past 2500 years. The symmetrical volcano, seen here from the NE, rises 800 m above its surroundings and is the highest peak of the Tongariro volcanic center. Tongariro is a large andesitic volcanic massif, located immediately NE of Ruapehu volcano, that is comprised of more than a dozen composite cones. Frequent explosive eruptions have been recorded from Ngauruhoe since its first historical activity in 1839.
The effects of erosion are visible in this view from the SW of two prominent stratovolcanoes on SW Umnak Island in the Aleutians. Mount Vsevidof (left) is a symmetrical, constructional volcano where frequent eruptions, which have continued into historical time, have overcome the effects of erosion. Recheschnoi volcano (right), in contrast, has been inactive for longer periods of time and has been extensively dissected by glaciers. Only small pyroclastic cones and lava domes have erupted during the past 10,000 years.
Wurlali volcano (also referred to as Damar), seen here from Cape Wilhelmus on the north, is part of Indoneisia's Banda Island chain. The 868-m-high stratovolcano was formed in the northern part of a 5-km-wide caldera, and has twin summit craters. During historical time only a single explosive eruption occurred, in 1892 from the summit crater.