There are 5,972 volcano images available on the GVP website.
Volcanic craters are the top surface opening of conduits that form by explosive excavation or ejection of rock and the build up of material around the vent, with minor contributions from collapse. Craters display a wide range of shapes and sizes resulting from differing eruption styles. Volcanoes can have various active craters over time and multiple eruptions can form overlapping or nested craters. Hazards include ballistic ejecta, pyroclastic flows (also called pyroclastic density currents), ashfall, lahars, lava flows, volcanic lightning, volcanic gas, and structural failure.
Ash surrounds a small crater on the NE side of the summit in 1942. Pavlof was in a period of almost continuous minor explosive activity from 1936 to 1948. Significant eruptions took place in 1936, July 1937, and 1942. By 1942 eruptions had filled the fissure that formed during the 1911 eruption. 
The summit crater complex of Mt. Garat with Lake Letas in the background, seen here from the S. A plume rises from the SE crater. Strong continuous degassing began following an increase in fumarolic activity in April 1991 and was continuing at the time of this July 1991 photo. Mt. Garat is located within the 6 x 9 km wide caldera that is partially filled by Lake Letas. The northern caldera rim is in the background.
The 200-250 m wide Karymsky summit crater formed following a long-term eruption during 1970-82. This early 1990's photo shows the crater from the NE. Several other prominent central Kamchatka volcanoes are in the background. Zhupanovsky, to the far left, is composed of four overlapping edifices constructed along an WNW-ESE line. Koryaksky is to the left-center, and the broad Dzenzursky massif to its right.
Monogenetic cones of the Chichinautzin volcanic field are seen here below the western flanks of Iztaccíhuatl. These cones, including Cerro Tenayo to the lower left, lie at the easternmost extension of the 90-km-wide Chichinautzin volcanic field, south of the Valley of Mexico. The compound Iztaccíhuatl volcano is mostly Pleistocene in age.
Cerro el Jabalí (upper left) and the adjacent Cerro el Sapien (immediately to the east) of the Michoacan-Guanajuato volcanic field produced the unvegetated lava flow extending across the top of the photo. Ashfall from Cerro el Jabalí scoria cone, located about 15 km SE of Parícutin, erupted about 3,830 years ago. The city of Uruapan is in the right side of the photo, south of the circular Costo (Cerro Cotji) maar.
An explosive eruption on 24-25 November 2005 deposited ash over the SE and SW parts of Grand Comore Island in the Indian Ocean (also known as Ngazidja Island). Ashfall occurred in Moroni, the capital city of the Comoros, located on the W-central coast. On 26 November this incandescent lava lake was observed inside Chahalé crater within the summit caldera of Karthala volcano. Within a few days the surface of the 60-80-m-wide lava lake had mostly solidified, and the eruption ended on 8 December.
The walls of Tiwu Nua Muri Kooh Tai, the middle of Kelimutu's three crater lakes, expose bedded hydrothermally altered rocks. Tiwu Ata Polo, the darker-colored crater lake to the SE, is visible beyond the far wall. Constant upwelling occurs at these two lakes, probably as a result of subaqueous fumaroles, directing floating sulfur in Tiwu Nua Muri Kooh Tai toward the crater walls.
Washibaike crater lies in the foreground with the granitic peaks of the Yari-Hodaka Range in the background to the S with Yarigatake (Spear Peak) in the center. The Washiba-Kumonotaira volcano group consists of a cluster of small volcanoes with possible lava domes. A tephra layer from Washibaike crater overlies the 6,300-year-old Akahoya Ash from Kikai volcano.
Santa Ana has four nested craters at its summit, seen here from the SW. A series of flank vents and cones have formed along a 20-km-long fissure system that extends from the lower NNE flank to the San Marcelino and Cerro Chino scoria cones on the SE flank. Historical eruptions have been recorded since the 16th century and have largely consisted of small-to-moderate explosions from both summit and flank vents.
MacKenney crater (right), constructed NW of an older cone at the left, has been the source of most of Pacaya's historical eruptions. Frequent Strombolian eruptions repeatedly build up the cone after it is partially destroyed by intermittent larger explosions. An extensive lava flow field produced from MacKenney cone since 1965 is in the background of this 25 January 1987 view from the NE.
The active Santa Ana crater lies at the SE end of series of four nested summit craters and contains a small lake not visible in this photo. The northern crater wall in the background exposes a series of lava flows and inter-bedded pyroclastic deposits. Several faults are visible in the crater walls, such as the one at the upper left. Later tectonic movements produced a graben in the central part of the crater with displacements of 50-70 m. 
This view from above the south rim of the crater of Mount St. Helens shows the lava dome partially filling the crater on 28 October 1986, at the very end of the 1980-86 eruption. After six years of episodic growth the lava dome reached a height of 250 m and a diameter of 1,100 m.
The cone at the lower left on the floor of Raung's summit caldera formed during an eruption in 1913. A lava flow erupted from the cone, extending to the right across the caldera floor. This aerial photo, taken some time before 1926, shows the steep, roughly 500-m-high SW caldera wall in the background.
The degassing crater of Galunggung volcano on 5 February 1983, a month after the end of the 1982-83 eruption. Plumes are shown rising from a late-stage scoria cone that formed in the center of the crater and from the margins of the crater wall. A lake that had begun to form in the crater at the time of this photo eventually grew to cover the cone.
Kengamine (left) and Gozengamine (right) peaks are seen from Onanjimine, another of the summit peaks of Hakusan volcano. The Kengamine lava dome and the Shiramizutaki lava flow extending from its base originated during an explosive eruption about 2,300 years ago. A pond fills the Midorgaike crater in the left foreground, which formed during an explosive eruption in 1042 CE.
The summit of Erta Ale contains a 0.7 x 1.6 km elliptical caldera containing pit craters. A plume rises from the N pit at the left, and a lava lake was active in the center pit crater at the time of this February 2002 view from the S. It is an isolated basaltic shield volcano that is the most active volcano in Ethiopia. Recent basaltic lava flows fill much of the caldera and have overflowed its rim on the southern side. One, or sometimes two, long-term lava lakes have been active since at least 1967.
The La Boca crater is a product of the final eruptions of the La Breña-El Jagüey maar complex. La Boca and a nearby small crater, La Boquita, were formed by the accumulation of spatter that welded together during Strombolian activity. The two small craters originated from vents at the SE end of one of the post-maar cones constructed within La Breña maar after the magma-water interaction phase.
The summit crater of the Vulcano Fossa cone is seen here in May 2011. On the crater wall to the right is discoloration from geothermal activity consisting of fumaroles across a fracture zone. In 2010 the average measured temperature across the field was 190°C.
An incandescent lava dome is visible in the Minamidake crater of Sakurajima in this 9 September 1981 aerial view. Sakurajima has been in near-continuous activity since 1955, with frequent mild-to-moderate explosions that commonly produce ashfall on the island.
Getang crater, also known as Kinyach, is on the N side of the Korosi summit area. The walls of the 600-m-wide, 120-m-deep crater expose trachytic lava flows. The youngest activity at Korosi, consisting of fissure-fed basaltic lava flows on the lower northern flanks, may have occurred only a few hundred to a few thousand years ago.
Aniakchak is a 10-km-wide summit caldera containing numerous cones, lava domes, and lava flows on the caldera floor. The largest intra-caldera cone is Vent Mountain that reaches 430 m in height and has a diameter at the base of 2.5 km. At least 20 Holocene eruptions may have occurred before the Aniakchak II caldera-forming eruption.
Okama crater of Goryudake within the Zaozan volcanic complex is shown here from the E. The 360-m-wide lake is about 60 m deep and is the site of many recorded eruptions. White mud deposited on the lake floor is periodically disturbed by gas emission, changing the color of the water.
Plumes rise from two small craters near the center of Marapi's broad E-W-trending summit. The background ridge in the shadow is the eastern rim of a larger crater, Kebun Bungo.
The 1980 eruption of Mount St. Helens dramatically altered the conical profile of the volcano. The eruption left a 2 x 3.5 km wide horseshoe-shaped crater, seen here from the NNE beyond Spirit Lake (center). The landslide of 18 May lowered the summit by 400 m and produced a highly mobile debris avalanche that swept into Spirit Lake and traveled down the North Fork Toutle River. The associated northward-directed lateral blast devastated about 600 km2.
The steep walls of Lua Poholo pit crater, immediately NE of Mokuʻāweoweo caldera, expose a small portion of the accumulation of thin, overlapping lava flows that form Mauna Loa. This view from the NE shows the caldera rim to the upper right. Lava flows from recent eruptions fill crater floor, including the most recent 1984 eruption.
The crater wall above the historically active crater lake within Kawah Merapi crater at the summit of Dempo volcano shows a series of alternating lava flows and pyroclastic deposits.
Moderate explosive eruptions beginning in October 2004 at Mount St. Helens were followed by the extrusion of a lava dome. This 21 June 2005 view from the NW shows the new dome with the 1980 crater wall in the background. The smooth-surfaced part of the dome, known informally as the Whaleback, formed by slow extrusion of viscous lava. The rougher surface to the right formed when portions of the dome collapsed, forming a talus slope. The crevassed, ash-covered surface of an uplifted glacier is visible to the left.
An eruption during 1950-51 formed the crater in the foreground within the larger Kaba Vogelsang crater on the upper ENE flank of Kaba volcano. The eruption began in March 1950 and lasted until April of the following year. An eruption on 7 March 1951 resulted in ashfall that destroyed forests on the volcano, and incandescent bombs were ejected on 2 March.
Santa Clara shield volcano, seen on the SW horizon beyond the rim of Cráter Elegante maar, is of late-Pliocene to Pleistocene age. The broad edifice is largely mantled by pyroclastic ejecta and lava flows of the basaltic Pinacate monogenetic volcanic series, which began erupting about 1.2 million years ago. More than 500 scoria cones and associated lava flows have formed across the Pinacate field and extend into the surrounding desert.
This vertical aerial photo shows part of the 12-km-wide summit caldera of Ambrym. The craters emitting plumes to the lower left are Marum (top) and Benbow (bottom). The caldera formed during a major Plinian eruption that included pyroclastic flows about 1,900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and also formed a series of cones and maars along a fissure system oriented ENE-WSW.
The small, low-angle, snow-free volcano near the center of this NASA International Space Station image (with N to the right) is Ozernoy volcano. This early Holocene cone is dwarfed by the Ksudach caldera to the SE (lower left).
Lava lake activity seen here on 21 August, began the night of 22-23 June 1994. Lava fountain height reached 30-40 m and the lava lake level was 5-10 m below the height of the 1982 lava lake. Lava lake activity continued until at least September 1995, with accumulation of lava on the crater floor from the end of April to mid-August 1995 causing the crater floor level to rise about 50 m. Observers saw nighttime glow from the crater in November 1995 and February-March 1996.
Fumaroles produce plumes along the floor and margins of Kawah Besar, a small crater with a shallow crater lake occupying Kaba Lama. This is the largest and westernmost of three major craters at the summit of Kaba volcano. The rim of 1.2-km-wide Kaba Lama forms the horizon.
The 1886 Tarawera eruptive fissure, seen from the N, formed across lava domes of the 800-year-old Kaharoa eruption. The red and black rocks of the 1886 eruption, 20-30 m thick here, overlie white rhyolitic Kaharoa eruption deposits. This view shows a 2-km-long section of the 8-km en-echelon fissure with gray rocks of the Ruawahia lava dome appearing at the far end.
Ash eruption from Ol Doinyo Lengai seen on 12 March 2008 from the NNE. This image shows that the E, N, and W flanks of the cone had buried the original crater rim. Oversteepening of the cone flank in places resulted in small landslides which can be seen just below the cone as dark material covering the lighter areas of older weathered carbonatite. The peak beyond the ash plume is the summit.
Two maars on the western flank of North Pagan volcano. Pyroclastic surge deposits from the latest eruption of the 1.5-km-wide eastern maar, seen here from the NE with South Pagan volcano in the distance, were radiocarbon dated to about 150 years old. This 24 May 1981 photo shows a lava flow (producing a gas plume) that originated from the summit crater during an eruption that began on 15 May.
Gases rise from the hydrothermally altered western wall of Santa Ana's inner summit crater above the acidic lake. A steep path down the NE crater wall (far right) provides access to the lake for geochemical sampling. Sequences of phreatomagmatic tephra units more than 100 m thick are exposed in the walls of the outer summit craters.
An aerial view from the south in the late 1970s shows a close-up of a 400-m-wide crater in a flat-lying former lava lake at the summit of the North Crater of the Tongariro volcanic complex.
This photo shows the Popocatépetl summit crater with fresh lava visible on 9 December 1997 after rapid lava extrusion during 5-6 December had almost covered the entire crater floor. The high point on the WSW crater rim rises 450 m above the floor of the 700-m-wide crater. The stratigraphy of the upper cone is visible in the far crater wall. 
An ash plume from the scoria cone within the caldera rises above the rim of the 2-km-wide Raung caldera in July 1988. Raung has erupted frequently in historical time.
Esan volcano has lava dome at the eastern tip of the Oshima Peninsula. This is Hokkaido's southernmost active volcano and a minor phreatic eruption in 1846 produced a lahar that caused many fatalities. Active fumaroles are at a thermal area on the upper NW flank.
The central area of the 14,000 km2 Harrat Khaybar volcanic field is shown in this December 2020 Planet Labs satellite image monthly mosaic (N is at the top; this image is approximately 49 km across). This area contains tuff rings and maars from phreatomagmatic activity and scoria cones, with some more recent lava flows. The larger light-colored crater near the center is Jabal Bayda, and the cone that produced the black lava flows to the north is Jabal Qidr.
Krasheninnikov is comprised of two overlapping edifices seen here from the north, with both cones topped by 800-m-wide craters. Construction of the northern cone (bottom) began about 6,500 years ago and eventually formed an inner cone within a 2-km-wide crater, the rim of which is visible to the left. The small inner cone of the northern crater was built during an eruption about 400 years ago which also produced a SW-flank lava flow.
Crater Peak crater on Mount Spurr is seen here producing a plume on 18 June 1992, the day after a brief violent explosion. Fresh deposits are on the interior of the crater and the pre-eruption crater lake is gone. The summit is visible behind the plume to the upper right in this view from the south.
Fremrinámar, NNE of Askja and SE of Mývatn lake, is a volcanic system that is constructed over the Ketildyngja shield volcano (center). Associated fissure systems, including the Sveinar fissure, extend 130 km to the N coast of Iceland. Mývatn lake formed as a result of the eruption of the 70-km-long older Laxarhraun lava flow from Ketildyngja shield volcano about 3,800 years ago. The latest eruption from Fremrinámar produced the Búrfellshraun lava flow about 2,500-3,000 years ago.
Crater Peak, a flank vent of Mount Spurr, is seen from the south with the snow-and-ice-covered summit lava dome complex in the background. Both the summit lava dome and Crater Peak were constructed within a 5-6 km wide scar formed by an earlier collapse. Crater Peak has been the source of about 40 Holocene tephra layers identified in the Cook Inlet basin.
An aerial overflight during World War II shows the summit of Ambae volcano from the SE. A broad cone containing three crater lakes is located at the summit within the youngest of at least two nested calderas. Post-caldera explosive eruptions formed the summit crater of Lake Voui (the light-colored lake) about 360 years ago. Lake Manaro Lakua at the lower right (also known as Manaro Ngoru) is alongside the eastern caldera wall.
This 1975 photo of the snow-covered summit of Mauna Loa from the SW shows the 2.4 x 4.8 km wide Moku‘āweoweo caldera in the center, with three circular craters in the foreground. South Pit (merging with the SW caldera rim), Lua Hohonu, and Hua Hou (foreground), formed through collapse along the upper SW rift zone. Mauna Kea is in the distance.
The lake-filled Laguna de Asososca maar in the foreground and the Cerro Asososca cone to the right were formed by eruptions at the southern end of a N-S fissure system of the Las Pilas volcanic complex in Nicaragua. The ages of these vents are not known. This view looks from the NE across the broad plain at the foot of the Cordillera de los Maribios to the Pacific Ocean in the distance.
Several nested craters are found at the summit of Santa Ana. Gases rise from fumaroles on the steep NE wall of an inner crater, within a roughly 900-m-wide crater. The 80-m-high crater walls expose tephra layers from phreatomagmatic eruptions. The walls of the two outer craters, which open towards the SW, are at the upper right.
An ash plume rises above a rockfall on the south side of the Mount St. Helens dome during a period of lava dome growth in June 1985. Lava dome growth occurred intermittently from 1980 to 1986.
Mount Martin is located at the southern end of the group of volcanoes in the Katmai area. Gases rise from the summit crater and sulfur has accumulated on the snow and ice in this 1990 view. The crater, which opens to the east, is the site of intense fumarolic activity and sometimes contains a small crater lake.
Santa Ana (or Ilamatepec) has several nested summit craters, with the active crater containing the blue lake shown in this February 2021 Planet Labs satellite image monthly mosaic (N is at the top; this image is approximately 16 km across). Several small cones have formed along the SE flank, down to the San Marcelino scoria cone that emplaced the 13-km-long lava flow eastwards in 1722. The Coatepeque Caldera is to the E and the Apaneca Range is to the W.
The maar crater in the foreground formed during an eruption in 1901 on the NE flank of Iliinsky volcano. Light-colored tephra was deposited around the rim of the crater and cover the flanks of the volcano. At the end of the eruption lava was extruded on the floor of the 200-m-deep, 1-km-wide crater. Zheltovsky is the volcano to the left of this image.
An ash plume erupts from the Suwanosejima summit crater, seen from a helicopter on 12 May 2001. Eruptions on the evening of 12 May and the morning of the 13th deposited up to 3 cm of ash in Toshima village, about 4 km NNW of the crater. After a quiet period of about 10 months eruptive activity had resumed on 19 December 2000 and continued intermittently until July 2004.
The Valle de Santiago in the NE part of the Michoacán-Guanajuato volcanic field NW of Lake Yuriria contains a group of maars formed by phreatomagmatic eruptions. The maars, four of which are lake-filled, range from 0.8 to 1.8 km in diameter, are 80 to 180 m deep, and are probably Holocene in age. This photo shows the Hoya Rincón de Parangüeo maar at the northern end of the group.
Light-colored lapilli deposits mantle the Jabal Bayda ("White Mountain") tuff cone; a lava dome is visible within the crater. Jabal Bayda and the Jabal Abyad lava dome (upper left) are part of the 14,000 km2 Harrat Khaybar volcanic field, located N of the city of Madinah (Medina). A 100-km-long N-S linear vent system in Harrat Khaybar contains lava domes, tuff rings, the Jabal Qidr stratovolcano, and numerous small basaltic cones.
Following the three eruptions of 1992, the interior of the Crater Peak vent at Mount Spurr contained tens of meters of new eruption deposits. All traces of the former lake had disappeared. A plume of steam and volcanic gas continued from the vent for several years. This photo was taken on 26 September, nine days after the eruption ended.
The SE-most pair of Kelimutu's crater lakes, Tiwu Ata Polo and Tiwu Nua Muri Kooh Tai, are seen here in an aerial view from the SE. A light-colored area of upwelling can be seen in the upper lake and this also occurs in the lower one. All three lakes are close to saturation with gypsum/anhydrite, contributing to color variations.
The summit of Ambae is seen looking approximately SE, with Lake Voui (foreground) and Lake Manaro Lakua (also known as Manaro Ngoru) on 20 March 1995. This was following an eruption on 2 March when bubbling and black sediment ejection were observed; the next day a 3-km-high steam-and-ash plume ejected lake sediments. Convection cells ~300-400 m in diameter can be seen in Lake Voui. The eruption took place near the center of the lake, between the two small islands. No eruptive activity was observed after 3 March.
Hikers peer into the 700-m-wide summit crater of Mount Fuji from its E rim. More than 100,000 people ascend its slopes yearly during the 2-month summer climbing season. A white meteorological observatory (upper right) sits at the summit, which is 240 m above the crater floor. A red oxidized scoria layer across the summit crater rim was emplaced about 2,100 years ago.
A 50-m-high spine formed on the 1986 lava dome at Augustine, seen here in 1987. The lava dome at the summit formed within an arcuate crater on the 1976 dome. As seen in this view from the SE, the surface of the 1976 dome is covered with pyroclastic ejecta from the 1986 eruption. The high point of the volcano (left) is a crater rim of the 1964 dome.
A plume emitting from active fumaroles is on the N side (left center) of the summit lake at Douglas volcano on the northern tip of the Alaska Peninsula. The small, 160-m-wide crater is one of the few ice-free areas on Douglas volcano. In 1992, the lake had a pH of 1.1 and a temperature of 21°C.
A gas plume rises above lava fountains in a lava lake in the summit crater of Nyiragongo volcano on 20 August 1994. Renewed lava-lake activity began the night of 23-24 June 1994 and continued into the fall of 1996. By August 1995 the surface of the lava lake had risen 50 m.
A compound lake-filled crater occupies the SW side of Central Island in the middle of Lake Turkana. A small young crater (left central) cuts the northern rim of the tuff ring, and another large crater lies behind it. These lakes partially fill craters up to 1 km wide and about 80 m deep, with the floors near sea level. The small islands (upper right) south of Central Island are part of the volcanic complex, and other cones lie beneath the lake surface.
The 100-m deep southern pit crater cuts the floor of the summit crater of Ethiopia's Erta Ale volcano. This November 1992 photo shows an active lava lake at the base. Fresh lava flows radiate away from the crater rim. They were produced by lava overflows from the crater, particularly during 1971-73. The southern pit crater has had an active lava lake since at least 1967, and possibly since 1906. Few observations are made of this remote volcano, located in the extremely hot and arid Afar region.
A series of minor phreatic eruptions, such as this one on 21 February 1982, took place from Crater Lake at the summit of Ruapehu volcano from October 1981 until April 1982. This eruption, seen here from the crater rim, is small compared to others that have taken place at Crater Lake.
A New Zealand Geological Survey volcanologist on the crater floor of White Island (also called Whakaari) volcano observes an ash plume on 9 February 1989. This was one of many small-to-moderate explosive eruptions that took place between 1986 and 1994.
The steep-walled, 600-m-wide summit crater of Kerinci volcano seen from the southern rim. The crater, which is located at the summit of Indonesia's highest volcano, is 450 m deep and is often contains a small lake.
This lake-filled maar and another small crater (left) are the Ukinrek Maars, which formed during an eruption in 1977 in a lowland area of the Alaska Peninsula west of the main volcanic chain. The contact between lighter and darker material in the walls of the lake-filled eastern maar marks the original pre-eruption surface, which is now buried by a dark apron of ejecta produced during the eruption.
Gas-and-steam plumes emanate from the new El Chichón crater in June 1982, about two months after a major explosive eruption formed it. The first sighting into the crater revealed three small lakes on the crater floor. These later merged into a single lake that reached a maximum depth of about 120 m. This aerial view from the east also shows gully erosion within pyroclastic flow and surge deposits on the flanks. 
The Atexcac maar is one of several lake-filled maars of the Serdán-Oriental volcanic field. The walls expose pyroclastic surge beds produced during formation of the maar. Cretaceous limestone beds and remnants of a basaltic scoria cone partially destroyed during formation of the maar are also exposed in the western crater walls. Abundant juvenile obsidian clasts are found in the surge deposits.
The steaming surface of Kawah Ijen crater lake from the southern rim in July 2000. The outlet of the lake is blocked by a small dam to the left. The maximum depth of the lake in 1996 was 180 m and the volume of the lake had gradually decreased from 0.044 km3 in 1922 to 0.036 km3 in 1996. The location of the most active vents below the lake surface have shifted to the W, towards the dam.
The small hills in the foreground are debris avalanche hummocks from a landslide on White Island in September 1914. The landslide occurred when part of the crater rim collapsed in the absence of any eruptive activity. The high-velocity avalanche swept across the crater floor, destroying the buildings of a sulfur-mining plant and burying 11 workers. The large hill in the background to the SE is not an avalanche hummock but a remnant of the outer crater wall.
Karymsky volcano contained a 250-m-wide summit crater following the 1970-82 eruption. Karymsky Lake fills the 3 x 5 km wide Akademia Nauk caldera to the south in this early 1990's aerial photo. Both Karymsky and Akademia Nauk erupted simultaneously on 2 January 1996. The brief one-day eruption was the first historical eruption of Akademia Nauk, but long-term activity continued at Karymsky.
The 500-m-wide Sumiyoshiike maar formed about 7,000 years ago. Sumiyoshiike and Yonemaru are two maars that formed in coastal lowland deposits N of the Aira caldera during a period of rising sea level at the beginning of the Holocene. The larger 1.2-km-wide Yonemaru maar erupted about 2 km W of Sumiyoshiike about 6,500 years ago.
An ash plume erupts from eastern crater of the newly formed Ukinrek Maars on 6 April 1977. West Maar formed during the initial days of the eruption that began on 30 March. Three days later explosions began at East Maar, 600 m away. At the peak of the eruption ash plumes reached up to 6 km above the vent. On the 4th day of the eruption a lava dome appeared within East Maar.
This view from the N looks into the acidic Cráter Activo lake with layered pyroclastic deposits exposed in the SW crater wall. The crater rim of the forested Rincón de la Vieja cone is to the upper left, with the non-volcanic Jilgueros lake at the top. 
One of the largest 20th-century eruptions in Kamchatka took place in March 1907 from Shtyubel' Crater (center) within the Ksudach caldera. Plinian explosive eruptions deposited 1.5 km3 of ash that extended as far as 1,000 km to the NNE. Plinian activity was followed by a laterally-directed explosion and the destruction of the Shtyubel' cone. Pyroclastic flows and surges traveled to the NW and over the Ksudach caldera walls. The eruption formed a chain of three craters (seen here from the NE) and lowered the height of the cone by about 650 m.
The broad summit of Santa Ana volcano has a 1.5-km-wide crater seen here from the south. The series of bedded phreatomagmatic tephra layers exposed in the crater wall in this photo form the summit region and overlie lava flows exposed lower in the crater walls.
Auckland, New Zealand's largest city, is constructed over the 600 km2 Auckland Volcanic Field. The field contains more than 50 maars, tuff rings, and scoria cones that were formed during eruptions over the past 193,000 years. Only one volcano was formed during the Holocene. About 620-570 years ago, two phases of eruptive activity formed a low shield volcano capped by a scoria cone at Rangitoto.
Gareloi in the western Aleutian Islands is seen here from the S. This photo shows lava flows with clear levees from a 1980s eruption. The 8 x 10 km diameter Gareloi Island consists of a stratovolcano with two peaks and a SE-trending fissure that formed during a 1929 eruption and extends to the sea.
Ashfall from Hoyo el Huanillo scoria cone (lower left) was radiocarbon dated to have formed about 9,300 years ago within the Michoacan-Guanajuato volcanic field. A small ash-covered lava flow extends a short distance to the NW of the cone, which is located 35 km NE of Parícutin. The Cerro Cucundicata scoria cone is to the lower right, and the Cerro Borrego and Cerro Tarucun cones are to the N, NE of the town of Cherán. The eroded Cerro Pacaracua edifice forms much of the upper part of the photo.
The Irazú summit crater is about 700 m wide and nearly 200 m deep and has been the source of most of Irazú's historical eruptions. Geothermal activity is frequently observed around of the lake, and the water color varies with changing atmospheric conditions.
This 30 March 1980 photograph shows two new summit craters formed by phreatic eruptions at Mount St. Helens beginning on 27 March. Continued explosions soon merged the craters into a single crater 300 x 500 m wide and up to 250 m deep.
A lava lake is visible inside Mbwelesu crater within Marum cone at Ambrym on 7 June 2007. Lava lake activity was observed during a field expedition from May to June. MODIS thermal alerts had resumed at Ambrym since November 2006 and eruptions took place in April and March 2007.
The renowned Parícutin scoria cone, which grew from a Mexican cornfield beginning in 1943, is one of the roughly 1,000 cones that form the massive Michoacán-Guanajuato volcanic field in central Mexico. White mineral deposits formed across the top of Nuevo Juatita in the foreground, a NE-flank vent that was the main source of lava flows during the last five years of the 1943-1952 eruption.
The greenish ~300-m-diameter Chahalé crater lake in the summit caldera complex of Karthala volcano is seen here in August 2003 before an eruption in April 2005. The photo, taken by an automatic camera located at the summit, looks from the NNE towards the SSW. Karthala is the southernmost and largest of the two shield volcanoes forming Grand Comore Island (also known as Ngazidja Island) and contains a 3 x 4 km summit caldera generated by repeated collapse. It has elongated rift zones extending to the NNW and SE.
The large forested (dark) area near the center of the photo is Cerro Tecolote, an eroded stratovolcano located roughly 50 km NE of Parícutin within the Michoacan-Guanajuato volcanic field. Cerro las Cabras (upper left) is a scoria cone that produced the lava flow extending across the upper part of the photo. Mexican Highway 15 travels across the flow, which is of Pleistocene age. Cerro Pajarito is one of the scoria cones south of Cerro Tecolote, and another cone is seen here on the SW flank.
Steam rises from the crater of White Island (also called Whakaari), one of the most active volcanoes of New Zealand. The small, uninhabited 2 x 2.4-km-wide island lies 50 km NE of the North Island. Frequent small-to-moderate explosive eruptions have been recorded since 1826, and Maori legends record earlier eruptions. This view from the SE shows the two overlapping 0.4 x 1.2 km wide craters at the summit of the largely submerged volcano.
Two summit craters at Erebus are seen in this view, with the 500 x 600 m Main Crater (left) containing an active lava lake (lower left) within the Inner Crater. A smaller inactive crater (center), referred to as Side Crater, is located immediately SW of Main Crater. The smaller West Crater is to the upper right.
Active fumaroles on the SE crater wall of the highly acidic Kawah Ijen crater lake, within one of the cones that formed in the 20-km-wide Ijen caldera. The 1-km-wide turquoise-colored crater lake is near the eastern rim of Ijen caldera and has been the site of phreatic eruptions in historical time and is noted for its sulfur deposits. 
A major explosive eruption about 1,800 years ago produced 10-15 km3 of tephra, including widespread pyroclastic flows, associated with formation of the 3.5 x 4.5 km Ksudach V caldera. The NE caldera wall forms the cliff to the upper left. Soon after this eruption, about 1,600 years ago, Shtyubel' cone began growing in the center of the caldera. A major eruption in 1907 created three large NE-SW-trending maar craters in the center of the photo. The craters have been largely filled by a lake.
The entire upper flanks of Pavlof are darkened by ash in this November 1973 photo taken after a 12-13 November explosive eruption. Small plumes rise from the crater on the uppermost NE flank just below the normally snow-covered summit.
The large crater in the center of the photo was produced on the SE flank of Mount Fuji during the 1707-1708 eruption. This major explosive eruption ejected more than 1 km3 of tephra and resulted in ashfall in the capital city of Edo (Tokyo). Three craters were formed sequentially along a NW-SE-trend from the summit. The primary vent of the eruption was the upper crater (center), which is 750 x 1,500 m in size and 750 m deep from the highest point on the crater rim.
This south-looking view across Pagan Island shows Alamagan Island in the distance. The wall across the center of the photo is the southern rim of a 7-km-wide caldera containing North Pagan volcano. The lake in the foreground is the westernmost of two maars on the western flank of North Pagan. The black lava flow on the caldera floor at the left center in this 16 June 1981 photo erupted from a vent on the south rim beginning on 15 May 1981.
The broad, irregular summit of Kelud volcano contains several lava domes and a crater lake that has been the source of frequent violent and sometimes devastating eruptions. Construction of outlet tunnels following an eruption in 1919 that killed 5,110 people has reduced the number of fatalities from pyroclastic flows and lahars during subsequent eruptions.
The summit of Norikura contains many small peaks and craters. The E (right) side of Enkodake (center) contains Kamegaike crater. Tsurugaike crater contains the pond in the center of the photo. The latest activity occurred during the Holocene and a recent eruption took place at the summit crater of Ichinoike.
This scoria cone on the floor of the Boquerón summit crater at San Salvador was built during an eruption that began on 6 June 1917 on the upper north flank of Boquerón. A chain of scoria cones formed, and a lava flow traveled to the northwest, cutting the railroad between Quezaltepeque and Sitio del Niño. The Boquerón summit crater lake began to boil by 10 June and disappeared by 28 June, after which this small cone (Boqueroncito) formed on the crater floor.
The summit of Douglas volcano on the northern tip of the Alaska Peninsula contains a warm and highly acidic crater lake approximately 160 m wide. An active fumarole field is also found on the shores of the lake.
The Azuma Kofuji cone with its 300-m-wide crater is one of many volcanic features of the Azumayama complex. This volcano group consists of a cluster of cones and lava domes. Volcanic activity has migrated to the E, with the Higashi-Azuma volcano group being the youngest. This photo was taken from the NW on the flanks of Issaikyoyama, which has been the site of historical eruptions (mostly small phreatic explosions).
A plume rises from the crater of Miharayama on Oshima island. It lies within a 4-km-wide caldera, the rim of which is prominently visible in this aerial photo from the SW. Dark-colored lava flows from the 1986 eruption cover part of the caldera floor. More than 40 cones are located within the caldera and along two parallel rift zones trending NNW-SSE across the island. The port city of Motomachi on the west coast is to the left and the island's airport is at the upper left.
Cráter Elegante is one of the largest maars of the Pinacate volcanic field, seen here from the WSW. The uneven area on the southern crater rim (to the right) is a scoria cone that was dissected during formation of the maar. Another darker scoria cone to the right is surrounded by lighter-colored pyroclastic surge deposits from the maar-forming eruptions. A third scoria cone (lower left) opens toward the rim of Cráter Elegante and is partially surrounded by the younger dark-colored lava flow in the foreground.
The 1976 lava dome, seen from the east in this 1982 photo of Augustine, formed within an arcuate crater rim that was produced by explosive removal of part of the 1964 lava dome during an earlier phase of the 1976 eruption. The small peak to the upper right is a remnant of the 1935 lava dome. Small plumes rise from the 1976 dome (center) and from fumaroles at the summit of the 1964 dome remnant (upper left).
Lava Butte is a scoria cone on the NW flank of Newberry volcano at the end of fissure system that extended from the caldera rim about 7,000 years ago. Following construction of the cone, the SW flank fissure at the base of the cone (in the foreground) fed a voluminous lava flow that traveled to the north and changed the course of the Deschutes River.
Balbi volcano forms the highest point on Bougainville Island and is part of a large number of coalesced cones and lava domes. Five well-preserved craters occupy a NW-SE-trending ridge N of the summit, which also has a crater. Crater C, containing a small lake, is seen here from the E. A plume from a fumarole field on the W flank of 600-m-wide Crater B is visible to the left. The latest eruption may have been as recent as the mid-19th century.
A plume rises from the summit crater of Nevado del Ruiz volcano on 10 December 1985. Pyroclastic surge and ashfall deposits from the 13 November eruption coat the glaciers. Glaciers on the upper NE-flank headwall of the Azufrado valley (foreground) were scoured by pyroclastic surges.
On 18 April 2005 a lava lake formed in the Chahalé crater, previously occupied by a crater lake. In this aerial photo, taken from the N on the morning of the 18th, considerable portions of the lava lake's surface still remained molten and incandescent. The lake's surface only remained molten only for a few hours, and by the next day its chilled surface emitted only gas plumes.
This elongate crater is along the northern flank of Pico Mayor, the summit of Acatenango. The first well-documented eruption of Acatenango took place from this N-flank vent beginning 18 December 1924. The eruption continued until 7 June 1925. On 14 March 1925 ash fell as far away as Pochuta.
Incandescent spatter is ejected from a vent in the summit crater of Yasur volcano on 8 September 1988. The volcano has produced continuous Strombolian or Vulcanian activity since at least 1774. The mild activity seen here is occasionally interrupted by more violent explosive activity, such as during 1878, 1968, 1972, 1974-75, and 1977.
This outcrop shows light-colored deposits from the 3,500-year-old Minoan eruption of Santorini filling a valley that eroded into darker tephra layers of Pleistocene age. The lower beige-colored unit filling the valley is a pumice-fall deposit from early in the eruption. It is overlain by laminated pyroclastic surge deposits that were produced when water came into contact with the magma reservoir as the volcano collapsed into the sea. The upper lighter-colored layer truncating both these deposits is a pyroclastic flow deposit.
This 19 April 2005 aerial photograph of the Karthala Chahalé crater was taken from the SE. The surface of the lava lake, which had been emplaced the day before, had chilled and was emitting a white plume. Much of the summit area displays recently-deposited tephra from explosive eruptions on the 16th and 17th.
The inner crater of Santa Ana is 500 m wide and is partially filled by a 250-m-wide greenish crater lake in this 1966 photo. Fumaroles are active on the crater wall and in the lake, and abundant sulfur deposits are located on the SW wall (upper left). The acidic crater lake has a pH of about 1, and bathymetric surveys have revealed a maximum depth of 27 m.
The highly fractured area on the right side of this 3 May 1980 photo is the renowned N-flank "bulge" of Mount St. Helens. Intense deformation producing northward displacements up to 2.5 m per day and reduction of rock strength by hydrothermal alteration caused the catastrophic collapse of the N flank, triggering the devastating magmatic explosive eruptions of 18 May.
The Mehrener maar is one of about 80 maars of the West Eifel Volcanic Field. The village of Mehrener is located on the shore of a lake partially filling the crater, whose rim lies behind the village. Maars, scoria cones, and small stratovolcanoes cover an area of 600 km2, W of the Rhine River. Most of the volcanic features formed during eruptions between about 730,000 and 10,000 years ago.
This photo of the NE slope of Suwanosejima was taken on 20 December 2000, the day after the onset of an explosive eruption. It shows the main active crater, Ontake (labeled 1), and two subsidiary craters (2 and 3). Explosive activity continued intermittently until July 2004.
Tiwu Ata Mbupu is the NW-most of three craters on Kelimutu. It is 850 x 600 m wide and contains a 67-m-deep crater lake. The shoreline of the lake is coated with red/yellow minerals and gypsum crystals. Lake color tends to vary seasonally.
Sannomegata (center), seen here from the NW with Toga bay in the foregound, is one of three small Megata maars along the tip of the Oga Peninsula. Lakes 300-700 m wide fill the maars, which are noted localities for mantle-derived xenoliths and are located immediately E and S of Toga Bay.
This view from the NE in June 1986 shows steam rising from the summit crater of Korovin, north of Atka. It has been reported to have a cylindrical vent of greatly variable depth depending on the presence of a lake.
The summit of Antarctica's Mount Erebus is the world's southernmost active volcano. It contains an elliptical 500 x 600 m wide crater whose NE side contains a 250-m-wide, 100-m-deep inner crater. The flat, snow-covered floor of the Main Crater is about 100 m below its rim. A plume rises from the inner crater that has contained an active lava lake since 1972.
The crater lake of the Cráter Activo of Rincón de la Vieja is seen here on 2 April 1998 from its eastern rim during the 1998 eruption. The eruption began with phreatic explosions during 15-18 February that produced steam plumes up to 2 km above the crater lake, and scorched vegetation on the NE side of the crater. On 16 February a lahar traveled around 12 km down the Penjamo and Azul rivers. Twenty explosions were recognized from seismic records, and additional explosions were recorded in May, June, and September. 
The Concepción summit crater is seen here in an aerial view from the west in 1994. The crater is 300 m in diameter and about 250 m deep. 
Santa Ana's active crater contains an acidic crater lake within the SE end of a series of four nested craters. This photo is taken from the northern rim of the second youngest crater and shows an older crater floor containing several small phreatomagmatic vents that formed during historical eruptions.
The two crater lakes of Kelimutu volcano on Indonesia's Flores Island are seen in this aerial view from the SW. Tiwu Nua Muri Kooh Tai (Lake of Young Men and Maidens) on the left and Tiwu Ata Polo (Bewitched or Enchanted Lake) are separated by a narrow crater wall about 35 m high. Phreatic eruptions have occurred from Tiwu Nua Muri Kooh Tai in the 19th and 20th centuries.
A plume is emitted from the active crater on the NW flank of Lopevi volcano in January 1999, six months after eruptive activity resumed in July 1998. The eruption took place within the elongated 1963 crater on the upper NW flank. A small lava flow erupted in December 1998 from the smaller cone onto the crater floor to the SE.
This large fissure produced during a major explosive eruption at Tarawera in 1886 is one of the youngest eruption features of the Okataina Volcanic Centre. Okataina is surrounded by extensive ignimbrite and pyroclastic deposits produced during caldera-forming eruptions. The subparallel NE-SW-trending Haroharo and Tarawera complexes consist of rhyolitic lava domes and associated lava flows that formed between about 15,000 and 800 years ago and impounded lakes against the margins of the Okataina ring structure.
Sequences of phreatomagmatic tephra layers are exposed in the southern and western crater walls of Santa Ana. The hydrothermally altered area to the lower right is the inner crater, which contains an acidic lake not visible in this photo. Four crater walls can be seen in this photo; the two outer walls appear in the center on and below the horizon, beyond the flat rim of the inner crater.
Waiowa (also known as Goropu) is an isolated tuff cone that was formed during 1943-44 by explosive eruptions through Paleozoic to pre-Cambrian metamorphic rocks. The active vents, seen here on 14 February 1944, were formed in an area without previous volcanic activity. Intermittent minor explosions began on 18 September 1943. Larger explosions occurred on 27 December 1943, 13 February, and 23 July 1944. After the final eruption on 31 August, the volcano was capped by a 500-m-wide crater that now contains a small lake.
Tavurvur, seen here from the SW on a boat in Matupit Harbor, is one of several post-caldera cones constructed along the NE margin of Rabaul caldera. The cone has an irregular crater rim with a low point on the SW side; its summit and flanks have several overlapping craters. Tavurvur has been the most active of Rabaul's volcanoes, with recorded eruptions since the 18th century. Tavurvur erupted simultaneously with Vulcan on the SW side of the caldera in 1937 and again in 1994.
Takachihomine peak (center) in the Kirishima volcanic complex is flanked on the E (right) by Ohachi, with its broad summit crater. Madudake cone is to the far right. Kirishima is a large group of more than 20 Quaternary cones within Kirishima National Park, located N of Kagoshima Bay. The late-Pleistocene to Holocene group of cones, maars, and underlying shield volcanoes occupies an area of 20 x 30 km.
The currently active Troitsky crater of Maly Semiachik formed during an explosive eruption about 400 years ago. The eastern crater wall shows light-colored hydrothermally altered rocks of the vent complex that are overlain by darker lava flows and fall deposits from eruptions that followed formation of the crater. A hot, acidic lake now fills the crater, which has been the source of historical eruptions.
This June 1956 shows gas emissions from a new circular sub-crater formed in the summit crater of Poás volcano during an eruption from 1952-57. Phreatic explosions increased in intensity from 1952 to early 1953. Ash emission began in May 1953 and the crater lake was gone by 22 May. The first juvenile material was observed in mid-July, and Strombolian activity continued until 1955, after which geyser-like activity resumed. Lava appeared in the crater in 1957, and a phreatic explosion ejected ash on 25 December 1957. 
An eruption from a SSW-flank fissure 16 July to 20 August 1986, produced the Kitazungurwa scoria cone and a lava flow that traveled 19 km down the SW flank. The lava flow partially covered the SW-flank lavas from the 1976-77 Murara eruption. On 18 August the eruption changed from continuous lava fountaining to Strombolian activity. Crops were destroyed by hot ejecta and 150 cattle died from ingestion of ash-covered vegetation.
Maly Semiachik is located within several nested Pleistocene calderas and composed of three overlapping edifices along a NE-SW line. Activity migrated to the SW, eventually forming the youngest cone, Ceno-Semiachik. It contains the historically active Troitsky crater, which formed during an explosive eruption about 400 years ago. It contains a hot, acidic lake this 1972 photo.
The Avachinsky cone was constructed during the late Pleistocene and Holocene within a horseshoe-shaped crater formed by late-Pleistocene flank collapse. The 250-m-deep summit crater seen in this view was completely filled with a lava during an eruption in 1991.
This June 1984 view looking southward across the north crater shows a fresh black lava flow and small spatter cones on the crater floor. This photo was taken early during the eruption episode that began in January 1983 and shows the considerable depth of the crater at the time. Continued emission of lava flows filled the crater to the level of the saddle at the top of the image by December 1988, at which time lava overflowed the rim into a shallow depression.
Fuji contains a 700-m-wide crater at the summit of the modern cone that is constructed over a group of overlapping volcanoes. The diagonal line to the lower right is a road that extends to the timberline on the N flank. 
Vulcan, seen here from the SE, was the source of the largest eruptions at Rabaul in 1994. Vulcan began erupting on 19 September from a N-flank vent. Activity intensified rapidly, producing a large eruption column that reached an altitude of 20 km. Pyroclastic flows traveled radially down the flanks of the cone as far as 3 km and resulted in darkness in Rabaul city. The eruption originated from a N-S-trending fissure, seen here at the right. The scarp in the foreground was produced by a 5-m uplift the day before the eruption.
The 325-m-wide Kepundan Bongsu, one of several historically active craters at the summit of Sumatra's Marapi volcano, is the largest and westernmost of a chain of craters covering a 1.2-km-long E-W line. Marapi is one of Sumatra's most active volcanoes, producing numerous small-to-moderate explosive eruptions since the end of the 18th century.
Lava in the center of the crater of Tavurvur volcano on 7 October 1994 as an ash plume rises from a vent to the E. Impact craters from volcanic bombs ejected by the volcano can be seen in the foreground on the flanks of the cone. Explosive eruptions from Tavurvur began on 19 September. Ash plumes initially reached a maximum height of 6 km, although typical heights were 1-2 km. A small lava flow was first seen in the summit crater of Tavurvur on 30 September.
A 1-km-wide maar was formed in 1901 on the NE flank of Iliinsky. The northern wall of the crater exposes areas of light-colored hydrothermally altered rocks at the base that are surrounded by talus deposits. The darker bedded layers above this are tephra fall deposits of ash and scoria from earlier eruptions of Iliinsky. The light-colored layers (upper left) on the rim of the crater are tephra fall and pyroclastic surge deposits.
McDougal crater on the NW side of the Pinacate Volcanic Field in NW México is the largest maar at Pinacate. This view from the SE looks across the 1,520 x 1,740 m wide crater, which contains playa deposits 130 m below the rim. The maar erupted through flat-lying alluvial terrain of the Gran Desierto.
A satellite image on 4 July 2004 showed fresh ash deposits on the upper E flank of Korovin. This photo, taken from the SE, show ash emplaced on the upper slopes of the SE crater.
The acidic crater lake of Santa Ana is within the deepest of the nested summit craters, seen here from the S in 2011. The floor of a larger crater is visible across the center of this photo, and both lava flows and deposits from explosive eruptions are exposed in the crater walls. 
The small 3 x 4 km Bobrof volcanic island lies 50 km W of Adak and 15 km W of Kanaga volcano. The irregular shoreline has a half-dozen small cliff-bound peninsulas. The geology and timing of volcanism on Bobrof are unknown, but pyroclastic flow deposits are present.
An aerial view of Popocatépetl from the east on 4 July 1997 shows a dark gray lava dome with a strong fumarole emanating from its center. This dome was extruded after an explosive event on 30 June 1997 produced an eruptive column that deposited a thin ash layer on Mexico City. The far crater wall reveals a stratigraphic profile of lava flows and fragmental material forming the upper part of the cone.
The youngest crater of Dempo volcano, at the WNW end of a series of six partially overlapping craters at the summit, contains a 400-m-wide crater lake that has been the source of frequent phreatic eruptions during historical time. A seventh smaller crater is located on the upper N flank. Dempo is one of Sumatra's most active volcanoes, frequently producing small-to-moderate explosive eruptions.
This lake-filled crater is part of the Katwe-Kikorongo volcanic field that stretches from the NE shore of Lake Edward to the western shore of Lake George. It is the most extensive of a series of volcanic fields in the Western Rift Valley of Uganda containing carbonatitic cones and maars, some of which contain lakes. Local stories suggest that volcanism in the area has continued into historical times.
A 750-m-wide crater filled with a lake truncates the summit of Kasatochi. Crater walls rise to a maximum height of 314 m above the lake surface, which is less than 60 m above sea level in this 1961 photo. The volcano is located at the northern end of a shallow submarine ridge trending perpendicular to the Aleutian arc and occupies an island volcano 2.7 x 3.3 km wide. 
Incandescent spatter ejected from a new lava lake at vent C of Mbwelesu crater at Ambrym volcano on 28 August 1999. Mbwelesu was constructed at the eastern rim of Marum crater in the west-central part of the 12-km-wide summit caldera. More frequent lava lake activity had been reported from several craters within the caldera since at least 1996. Lava lake activity had also been previously noted by infrequent visitors to the summit caldera during the late 1980s and early 1990s.
Lower Tama Lake on Tongariro was formed late in a series of eruptions that began about 10,000 years ago. The eruptions included the emplacement of two lava flows from Upper Tama Lake with a combined volume of 0.2 km3 and a smaller lava flow from Lower Tama Lake.
A lava dome partially fills the summit caldera of Berg, with Kolokol in the background to the S. They are part of a group of Holocene volcanoes in central Urup Island that is named after the most prominent cone. 
The Popocatépetl summit crater is seen here from the NW on 16 June 1997. The irregular crater floor has several vents and some active fumaroles. The photo was taken five days after an ash eruption on 11 June that produced a 4-km-high plume and was accompanied by lahars that reached several towns to the east. Another strong explosion on 30 June was followed by lava extrusion on the crater floor.
The small craters Kepundan B and C in the foreground, seen here from the N, are two of many historically active craters along the elongated summit of Marapi volcano on Sumatra. A thick plume in the background rises above the westernmost summit crater, Kawah Bongsu.
Lake-filled Rokkannon-Miike is one of several maars in the Kirishima volcano group. It is located NW of Karakunidake in the NW part of the group. The forested rim of the maar is across the center of the photo and the peak behind it is Shiratoriyama.
An aerial view into East Maar on 3 April 1977 shows incandescent lava on the floor of the crater and a small vent above it that is producing an ash plume. The 1977 eruptions of Ukinrek Maars began on 30 March at West Maar, which formed during the first three days of the eruption. East Maar formed during the next seven days at a location 600 m E. A lava dome, now covered by a crater lake, formed on the floor of East Maar.
The Lake Dalny maar formed about 7,600-7,700 years ago in the the northern area of Uzon caldera. Tephra deposits from this eruption are found within 5 km from the lake. The 1-km-wide maar is surrounded by a 60-m-high tephra ring that forms the flat slope on the far side of the lake. The northern wall of Uzon caldera rises behind it.
The Apoyeque caldera to the left and the Xiloá Maar to the right are part of the Apoyeque volcanic complex shown in this December 2019 Planet Labs satellite image monthly mosaic (N is at the top; this image is approximately 27 km across). Apoyeque is one of 11 features within the Chiltepe Volcanic Complex at the northern end of the Nejapa Volcanic Field. The ridge to the ENE of the caldera is composed of cones, domes, and lava flows, and Cerro Talpetate is south of the maar.
The Pico de Orizaba summit crater is 400 x 500 m with a crater floor 300 m below the summit on the NW side of the rim. Climbers' tracks can be seen on the Jamapa Glacier to the lower right. 
A lava lake within Halema‘uma‘u produces a gas plume on 23 November 1968, shortly after activity began. This period of lava lake activity continued through to July 1968.
This view from the west on 4 November 1982 shows the impact of the El Chichón eruption about seven months later. Fumaroles are present around the new lake partially filling the crater, and the surrounding area was devastated by pyroclastic flows and surges. The 1982 crater is located within an older 1.5 x 1.9 km crater.
Kawah Verbeek, also known as Kapundan Tenga or Kepundan Tenga, is located at the western end of a chain of several historically active craters along an E-W line at the summit of Sumatra's Marapi volcano.
A Vulcanian ash plume rises from the Bárcena crater on 9 September 1952, more than a month after the start of the eruption. The roughly 300-m-wide crater is seen here from the east. Explosions producing eruption columns that rose to about 600 m above sea level were observed at 20-minute intervals, along with occasional small pyroclastic surges that swept down the flanks of the cone and sometimes reached the coast. The roar of the eruption was heard above the noise of the plane's engine.
A plume rises from a crater lake inside the new island formed during an eruption at Ambae beginning on 27 November 2005. This 9 January 2006 view looks toward the N. The new island was more than 500 m wide at this time and contained an internal lake.
This September 1946 photo of Great Sitkin from the E rim of the summit crater shows a plume rising above a lava dome emplaced in the crater in March 1945. The fissures in the ice were produced as the dome grew through the summit glacier.
An ash plume erupting from the crater of White Island (also called Whakaari) on 25 March 1988. This was one of many phreatomagmatic and magmatic eruptions that took place from 1986 to 1994 from the small island volcano 50 km NE of New Zealand's North Island. Large eruptions on 14 March and 27 April 1988, produced 3.5-km-high ash plumes.
An acidic lake occupies Troitsky crater, the youngest and southernmost crater of Maly Semyachik where historical eruptions have occurred. The conical peak in the distance is Karymsky, 15 km SW, which was constructed within a Holocene caldera.
This August 1922 photo from the NW shows the still vegetation-free summit of Kelud volcano following the powerful May 1919 eruption and the relatively mild December 1920 eruption. The 1919 eruption produced devastating pyroclastic flows and lahars that killed over 5,110 people. This prompted an engineering project to construct tunnels to lower the level of the crater lake, which was completed in 1926. A milder explosive eruption in 1920 was accompanied by extrusion of a small lava dome beneath the crater lake. 
The 800-m-wide crater of the northern cone of Krasheninnikov is seen here looking west across the crater. An eruption 400 years ago formed the small Pauk cone within this crater, and also produced a lava flow from a vent on the upper SW flank of the southern cone (at left out of view).
Phreatomagmatic eruptions produced when magma came in contact with groundwater eject an ash plume at the Ukinrek Maars on the Alaska Peninsula. This photo from the south on 5 April 1977 shows explosive eruptions from East Maar, one of two new craters that formed in glacial sediments, in an area without previous volcanic activity. The hummocky, snow-covered surface in the foreground is a debris avalanche deposit from Peulik.
Four years after the powerful 18 May 1980 eruption of Mount St. Helens, a lava dome partially fills the crater. The dome, seen here from the north on 16 May 1984, grew during episodic periods of rapid growth that lasted from 1980 until 1986. By the end of the eruption the dome filled much of the crater floor, reaching a width of 1,100 m and a height of 250 m.
The bottom of El Jagüey maar is occupied by a small lake which marks the level of the groundwater table that lies about 60 m below the top of the surrounding lava plain and serves as a critical regional water hole for cattle (foreground). Explosions occurred when rising magma encountered this aquifer and produced the intersecting La Breña-El Jagüey maars. The NW rim of the 1,400-m-wide La Breña maar forms the horizon beyond the saddle between La Breña and the 700-m-wide El Jagüey maar.
The roughly 800-m-wide San Miguel crater is seen here in 2011 with fumaroles in the geothermal area on the far crater wall producing small gas-and-steam plumes. Different colors in the crater walls are from various levels of oxidation and geothermal alteration of the rock.
An eruption from White Island (also called Whakaari) on 12 February 1977 is viewed from off the NE coast. The ash plume originates from the Christmas Crater vent, formed the previous year, shortly after the start of the eruption on 18 December. The first 20th century eruption to produce new magmatic material took place a month after the date of this photo. Intermittent phreatomagmatic eruptions continued until late 1981.
Lake Nyos is the most renowned of the numerous maars and basaltic cinder cones associated with the deeply dissected Mount Oku massif. The 1.2 x 1.9 km wide lake, seen here from the south, was the site of a gas-release event on 21 August 1986 that caused at least 1,700 fatalities. Wave damage stripped the peninsula at the left of vegetation. The emission of around 1 km3 of magmatic carbon dioxide has been attributed to either non-volcanic overturn of stratified lake waters, to phreatic explosions, or to injection of hot gas into the lake.
A steam plume rises from Cráter Activo of Rincón de la Vieja, seen here from the south with an acidic crater lake filling the innermost of two nested craters. Frequent eruptions and acid rain have kept the flanks of the cone unvegetated. Remobilization of fresh deposits has produced lahars down the Quebrada Azufrosa to the upper right.
An eruption plume rises above a new scoria cone that formed on the SW flank of Mount Cameroon on 16 October 1982. The eruption occurred from a NNE-SSW-trending radial fissure at the location of an older scoria cone. A lava flow traveled 12 km down the SW flank to within about 6 km of the Atlantic coast. Two towns were evacuated, and tephra caused damage to plantations. The eruption ended on 12 November.
The summit crater of Peuet Sague is part of a large volcanic complex in NW Sumatra. The first recorded historical eruption took place during 1918-21, when explosive activity and pyroclastic flows accompanied summit lava-dome growth. The historically-active crater has typically produced small-to-moderate explosive eruptions.
A plume rises above Ontake, the summit crater of Suwanosejima. The 8-km-long island consists of a stratovolcano with two historically active summit craters. The dipping scarp at the top of the image opens towards the sea on the E flank and formed by edifice collapse. This is one of Japan's most frequently active volcanoes and has been in a state of intermittent Strombolian activity since 1949.
Ukinrek Maars are two phreatomagmatic explosion craters that were created in an area without previous volcanic activity during a 10-day-long eruption that began on 30 March 1977. A greenish lake fills East Maar, the largest of the two in this 1994 view from the south. The smaller West Maar is surrounded by dark tephra near the left margin. Gas Rocks, an older volcanic center, forms the peninsula extending into Becharof Lake in the background.
The northern crater of Ol Doinyo Lengai is seen here in February 1980 from the summit. The steep-walled inner crater formed during the explosive eruptions of 1966 and 1967. Another eruption began three years after this photo was taken. By December 1988 the crater filled with lava that had overflowed the near southern crater rim at the lower center of the photo.
The 1-km-wide, lake-filled Ara-Shetan maar is located at the S end of the Butajiri-Silti volcanic field. It consists of a large group of basaltic scoria cones, maars, and lava flows in an 80-km-long, NE-SW-trending area near the W margin of the Ethiopian Rift. At least 13 maars, many filled by lakes, are located near the town of Debre Zeit, SE of Ethiopia's capital city, Addis Ababa. 
Lua Poholo pit crater is immediately NE of Moku’aweoweo caldera. The crater walls expose a small portion of the massive pile of thin, overlapping lava flows that have formed the summit of Mauna Loa. This 1987 view from the NE shows the western Moku’aweoweo caldera rim. The lava flows covering the caldera floor of the caldera were erupted in 1984.
The acidic crater lake at the summit of Poás is seen here from the overlook on the southern crater rim. The von Frantzius cone in the background formed along the northern rim of the innermost of two large nested calderas at the summit. The crater lake has been the source of frequent phreatic eruptions.
Two lakes of variable color lie with the summit caldera of Ambae volcano, as seen in this view from the W. The light blue lake in the foreground is Lake Voui (or Vui), which is enclosed in the crater of a tuff ring within the summit caldera. The dark blue Lake Manaro Lakua lies between the tuff ring and the E caldera wall. Ambae, the most voluminous volcano of the New Hebrides archipelago, forms a 16 x 38 km island. Pentecost Island appears in the background.
Kelimutu, a small volcano on Flores Island, is noted for its three crater lakes of different colors. This aerial view from the SW shows Tiwu Ata Mbupu at the lower left, and the two craters of Tiwu Nua Muri Kooh Taiand Tiwu and Ata Polo at the upper right. Water color varies periodically with variations of blue, green, and red. Phreatic eruptions have occurred from the middle lake in historical time.
This photo taken on July 1987 looks into the double summit crater of Telica volcano in Nicaragua. An older shallower crater is located on the SW side (top). A plume rises from fumaroles in the 120-m-deep NE crater (bottom), which is the source of recent eruptions. 
On 27 May 1988 this lava lake was observed in Mbwelesu's crater, which along with Marum, was emitting ash plumes. Airline pilots had reported ash plumes below 12 km altitude from Benbow on 13 February. Vanuatu geologists reported increased activity from Benbow during 12-14 February, after which the volcano returned to normal. On 9-10 August lava flows were emitted from a new cone along the S flank, Niri Taten, and traveled towards the southern caldera wall. This eruption ended on 23 August.
This 400-m-wide crater is at the summit of the cone that formed within the caldera at the summit of Chachadake on the NE tip of Kunashir Island. The SE part of the crater rim (upper right) is the highest point, seen here in October 1990. 
Gas-and-steam plumes rise from fumaroles on the summit ridge of Zhupanovsky in February 1990. This view from the west shows fumarole plumes rising from the flanks of the historically active crater (bottom) and from the ridge above it, which forms one of four cones. The peak at the top of the photo is the summit.
A small spatter cone ejects incandescent lava bombs at the bottom of MacKenney crater in early February 1990. Activity had resumed at Pacaya in early January after a long quiescence following a major explosive eruption 7-10 March 1989. This eruption removed the upper 75 m of MacKenney cone and enlarged the 50 x 75 m crater to the 200 x 350 m seen here.
A small lava flow, possibly produced during or before the 1870-75 eruption of Ceboruco, descended eastward from the rim of a crater within the inner caldera. This flow traveled 500 m to the east. The small crater to the right of the flow formed in the NE side of the larger crater. These are part of a complex group of features within the nested summit calderas.
The summit of Kusatsu-Shiranesan contains three craters with the largest, Yugama, holding the turquoise lake shown here. Rafts of yellow sulfur float on the surface of the acidic lake. This 1977 view looks across the lake from the SW-most crater (Karagama) to the NE-most crater (Mizugama), located beyond the notch to the left. Small-to-moderate phreatic explosions have been recorded from all three craters since the 1800s.
The large, horseshoe-shaped crater left by the collapse of Mount St. Helens on 18 May 1980, is typical of scarps created by massive volcanic landslides. The collapse removed nearly 1 km of the summit, leaving a 2 x 3.5 km crater open to the north. This June 1982 view shows a lava dome that began growing within the new crater.
This aerial view shows the Popocatépetl summit crater in 1996, following the 1994-95 eruptive period. Subsequent activity has been both effusive and explosive, with periodic extrusion and explosive removal of lava domes emplaced on the crater floor. This aerial view is roughly from the north, with the summit out of view to the right.
A plume rises from an incandescent vent on the floor of the crater of Nakadake on 25 April 1985. Moderate eruptions that ejected mud and ash had begun in April 1984 and continued intermittently until June 1985. Frequent ash eruptions occurred from 1 March to the night of 5-6 May 1985.
Xico is a low circular tuff ring within Mexico City that is part of the Chichinautzin volcanic field, seen here from the S. This volcano was formed by phreatomagmatic eruptions through the middle of Lake Chalco, the remains of which can be seen surrounding the tuff ring. Chalco and Lakes Texcoco and Xochimilco were formed when lava flows blocked river drainages to the S. 
The steep-walled craters of the Marum cone complex at the summit of Ambrym volcano, seen from the east. Ambrym contains a 12-km-wide caldera and is one of the most active volcanoes of the New Hebrides arc. A thick pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim.
Plumes rise from a crater and a lava flow near the summit of Mount Cameroon in 1982. More than 100 small cinder cones, often fissure-controlled parallel to the long axis of the massive 1,400 km3 volcano, occur on the flanks and surrounding lowlands. During historical time, explosive and effusive eruptions have occurred from both summit and flank vents. In 1922, a lava flow from a SW-flank vent reached the Atlantic Ocean.
Lake-filled Rokkannon-Miike is one of several maars at Kirishima volcano, seen here with a highway along the rim. The Kirishima volcano group consists of cones, maars, and underlying shield volcanoes scattered over a 20 x 30 km area N of Kagoshima Bay. Numerous small-to-moderate explosive eruptions have been recorded at Kirishima since the 8th century.
The Casa Diablo geothermal plant in the Long Valley caldera taps the high heat flow originating from the magma system below. Several commercial and scientific exploratory holes have been drilled here to depths of 100 to 2,000 m.
Kometsuka scoria cone (lower left) formed about 1,800 years ago in the Aso caldera complex. Clouds are above the broad caldera floor surrounding the cone complex and the NW wall of the 24-km-wide caldera is visible behind the cone. The caldera formed during four major Pleistocene explosive eruptions between 300,000 and 80,000 years ago.
Scoria cones, such as Eve Cone on the flank of Edziza volcano, are formed by the explosive ejection of fragmental material that accumulated around the vent. This symmetrical cone is part of the Desolation Lava Field on the northern flank of Edziza and is one of the youngest features of the volcano. Basaltic lava flows erupted from the base of the cone, which reaches about 150 m high and has a 45-m-deep crater.
Cráter Elegante, seen here in an aerial oblique view from the NW, is a 1.6-km-wide maar in the Pinacate volcanic field. Within the crater walls are exposed basaltic lava flows, sills, and dikes pre-dating formation of the maar, which are overlain by pyroclastic surge deposits that cover the rim and outer flanks. Lake beds within the maar have been radiocarbon dated at between about 13,000 and 17,000 years, indicating a late-Pleistocene age for the maar-forming eruptions.
The primary Aniakchak 1931 eruption site is against the NW caldera wall. This 600-m-wide crater produced intermittent explosions of pumice-lithic tephra over the course of several weeks in May and June 1931. During the final phases of the eruption a small lava flow formed in the bottom of the crater. The fissure eruption cut through Vent Mountain and across the caldera floor to the western caldera wall.
A stream of lava from a vent at Mauna Ulu (above the top of the photo) cascades into Makaopuhi crater during an early stage of the 1969-74 Mauna Ulu eruption. A thick stack of older lava flows that were erupted along Kīlauea's East Rift Zone is exposed in the Makaopuhi crater wall.
The NE wall of the Ksudach Shtyubel' crater is capped by bedded layers of tephra fall, pyroclastic flow, and pyroclastic surge deposits from the 1907 eruption. Three craters, 1.5, 0.6, and 0.4 km wide, formed along a NE-SW line. The eruption reduced the height of Shtyubel' cone by about 650 m and Shtyubel' lake filled the craters. The NE wall of Ksudach V caldera, inside which Shtyubel' cone was constructed, is visible at the top of the photo. 
This aerial view from the west shows the new Volcán Bárcena summit crater producing a plume. The 700-m-wide crater had grown to a height of about 380 m in the first two weeks of the eruption. At the time of this 20 September 1952 photo, taken about seven weeks after the start of the eruption, the first of two lava domes had emerged in the summit crater. Extrusion of a lava flow that formed a delta on the far SE side of the island had not yet begun.
A small eruption on 10 December 1952 took place from the moat between the inner (dark-colored) and outer lava domes in the Bárcena summit crater. A lava dome was first observed on 20 September, when it was about 8 m high and 55 m wide. On 15 November the dome was observed to fill about half of the 700-m-wide crater. At the time of this photo, an older outer dome littered with breadcrust bombs and ejecta surrounded the new inner dome.