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The Ijen volcano complex at the eastern end of Java consists of a group of small stratovolcanoes constructed within the large 20-km-wide Ijen (Kendeng) caldera. The north caldera wall forms a prominent arcuate ridge, but elsewhere the caldera rim is buried by post-caldera volcanoes, including Gunung Merapi stratovolcano, which forms the 2799 m high point of the Ijen complex.
Le Kawah Ijen se situe en Indonésie, à l'extrême est de l'île de Java, dans la province de Java-Orientale et dans le sud-est de la caldeira de Kendeng du volcan Ijen, adossé au flanc ouest du Merapi, le point culminant de ce massif volcanique à ne pas confondre avec l'autre volcan Merapi de l'île de Java.
Il est entouré par le Merapi à l'est, la caldeira de Kendeng au nord-ouest, le Papak immédiatement à l'ouest et le Rante au sud-ouest.
The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid.
Images were taken from a height of 2799 m above sea level, while climbing the mountain crater of Ijen, East Java Indonesia.
The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid.[2]
The beauty of Ijen mountain is not on the crater area only, but also when the sun rises from behind the mountain and the surrounding natural scenery ..... it's amazing!
Images were taken from a height of 2799 m above sea level, while climbing the mountain crater of Ijen, East Java Indonesia.
This is the largest volcanic crater in the world.
The catastrophic eruption of Mt. St. Helens 20 years ago today (on May 18, 1980), ranks among the most important natural events of the twentieth century in the United States. Because Mt. St. Helens is in a remote area of the Cascades Mountains, only a few people were killed by the eruption, but property damage and destruction totaled in the billions of dollars.
Mount St. Helens is an example of a composite or stratovolcano. These are explosive volcanoes that are generally steep-sided, symmetrical cones built up by the accumulation of debris from previous eruptions and consist of alternating layers of lava flows, volcanic ash and cinder. Some of the most photographed mountains in the world are stratovolcanoes, including Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Hood in Oregon, and Mount Rainier in Washington. The recently erupting Mount Usu on the island of Hokkaido in Japan is also a stratovolcano. Stratovolcanoes are characterized by having plumbing systems that move magma from a chamber deep within the Earth's crust to vents at the surface.
The height of Mt. St. Helens was reduced from about 2950 m (9677 ft) to about 2550 m (8364 ft) as a result of the explosive eruption on the morning of May 18. The eruption sent a column of dust and ash upwards more than 25 km into the atmosphere, and shock waves from the blast knocked down almost every tree within 10 km of the central crater. Massive avalanches and mudflows, generated by the near-instantaneous melting of deep snowpacks on the flanks of the mountain, devastated an area more than 20 km to the north and east of the former summit, and rivers choked with all sorts of debris were flooded more than 100 km away. The area of almost total destruction was about 600 sq. km. Ash from the eruption cloud was rapidly blown to the northeast and east producing lightning which started many small forest fires. An erie darkness caused by the cloud enveloped the landscape more than 200 km from the blast area, and ash could be seen falling from the sky over the Great Plains, more than 1500 km distant.
This image was acquired by Landsat 7 on Aug. 22, 1999. It was produced at 30-m resolution using bands 3, 2, and 1 to display red, green, & blue, respectively ("true color"). Some of the effects of the massive eruption on May 18, 1980, can still be seen clearly, especially on the northern and eastern flanks of Mount St. Helens, which are still mostly barren (shades of white and gray). The crater is in the center of the image. Note the streaking from the crater (gray on the image). These are the remnants of pyroclastic flows (superheated avalanches of gas, ash and pieces of rock) that carved deep channels down the slopes and onto the relatively flat areas near the base of the mountain. The partially-filled Spirit Lake can be seen just to the northeast of the crater (blue-black on the image), and the where most of the energy was directed during the blast is the gray area immediately to the northwest of the crater. However, on other parts of the mountain, the rejuvenation process is obvious. Ash deposits have supplied minerals which have accelerated vegetation growth (various shades of green). Though far from what it looked like 20 years ago, Mount St Helens is actively recovering.
Credit Data courtesy Landsat 7 project and EROS Data Center. Caption by James Foster, NASA Goddard Space Flight Center.
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An active volcano en route from Lima to Quito. I believe this is Tungurahua. Tungurahua is 5,023 m (16,480 ft) and, like several other tall stratovolcanoes in the area, was perennially snow-capped until it began erupting in 1999, at which point the snows melted.
The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding Valley to get paid.
The active crater at Kawah Ijen has a diameter of 722 metres (2,369 ft) and a surface area of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
The lake is recognised as the largest highly acidic crater lake in the world.
Near Bend, Oregon
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Three Sisters
Aerial view from the southeast looking north of the Three Sisters volcanoes, three mountains sparsely covered with ice and snow. From left to right the image shows South Sister, Middle Sister, and North Sister, with a black lava flow in the left foreground.
The Three Sisters, looking north
Highest point
Elevation
South 10,363 ft (3,158.5 m)[1] NAVD 88
Middle 10,052 ft (3,063.7 m)[2][3] NAVD 88
North 10,090 ft (3,075.3 m)[4][5] NAVD 88
Prominence 5,588 feet (1,703 m) (South Sister) [6]
Listing US most prominent peaks, 85th (South Sister)
Coordinates 44°06′12″N 121°46′09″WCoordinates: 44°06′12″N 121°46′09″W [7]
Geography
Three Sisters is located in Oregon
Three Sisters
Three Sisters
Location in Oregon
Location Lane and Deschutes counties, Oregon, U.S.
Parent range Cascade Range
Topo map USGS South Sister and North Sister
Geology
Age of rock Quaternary
Mountain type Complex volcano, made up of stratovolcanoes and a shield volcano
Volcanic arc Cascade Volcanic Arc
Last eruption 440 CE[8]
Climbing
Easiest route Hiking or scrambling, plus glacier travel on some routes[9]
The Three Sisters are volcanic peaks that form a complex volcano in the U.S. state of Oregon. They are part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Washington and Oregon to Northern California. Each more than 10,000 feet (3,000 m) in elevation, they are the third-, fourth- and fifth-highest peaks in Oregon. Located in the Three Sisters Wilderness at the boundary of Lane and Deschutes counties and the Willamette and Deschutes national forests, they are about 10 miles (16 km) south of the nearest town, Sisters. Diverse species of flora and fauna inhabit the area, which is subject to frequent snowfall, occasional rain, and extreme temperature variation between seasons. The mountains, particularly South Sister, are popular destinations for climbing and scrambling.
Although they are often grouped together as one unit, the three mountains have their own individual geology and eruptive history. Neither North Sister nor Middle Sister has erupted in the last 14,000 years. South Sister last erupted about 2,000 years ago and might erupt in the future, threatening life within the region. After satellite imagery detected tectonic uplift near South Sister in 2000, the United States Geological Survey improved monitoring in the immediate area.
From Wikipedia
Sea of morning cloud in the midst of a crater.
Tengger Caldera, East Java, Indonesia
summit elevation 2329 m
stratovolcanoes
It is a scenic tourist destination in East Java. Spectacular sunrises, and majestic views.
We travel during midnight, stop halfway and were driven up by jeep and reach the summit at about 6.30am where hundreds of visitors had already been there earlier to catch the first glimpse of the sunrise.
Today, a seabed of clouds cover the plains below and only the tip of the volcano emerges from the thick cloud surrounding it. Beautiful display of colors of sunrise.
Pagan Island, Northern Marianas is featured in this image photographed by an Expedition 30 crew member on the International Space Station. A steam plume flows south from the peak of Pagan Island's northernmost volcano in this photograph. Pagan is part of the Commonwealth of the Northern Marianas, an island chain of volcanoes that form the margin between the Pacific Ocean (to the east) and the Philippine Sea (to the west). Pagan is made up of two stratovolcanoes separated by an isthmus, and is one of the more volcanically active islands. The last eruption was in 2010, but the island was completely evacuated in 1981 when a large eruption forced the small Micronesian community to flee. According to NASA scientists, the islands themselves mark the tectonic boundary where the old, cold Pacific plate is subducted beneath the younger, less dense Philippine Sea crust at the Marianas Trench. The subduction results in substantial volcanic activity on the upper plate, forming the island arc of the Marianas. Considered to be one of the type examples for an oceanic subduction zone, the Marianas Trench includes the deepest spot in Earth's oceans (more than 10,000 meters). The foreshortened appearance of the island is due to the viewing angle and distance from the space station, which was located over the Pacific Ocean approximately 480 kilometers to the southeast of Pagan Island when the image was taken.
Image credit: NASA
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The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
Ijen Crater (Indonesian : Kawah Ijen) is an enormous crater filled with steaming turquoise acid water that produces sulfur and mined traditionally. It is 2386 meter above sea level and part of a group of stratovolcanoes in East Java, Indonesia.
I went down to the bottom of the crater despite the super thick sulfuric fume that burned my eyes and throat, to experience how tough life of a sulfur miner.
Find more pictures and story about life of sulfur miners on www.diankarlina.com/projects.html
The Lago de Atitlán is a beautiful lake in the highlands of Guatemala; the water level is at 1562 meters (5,125 ft). The lake basin is volcanic in origin, filling an enormous caldera formed by an eruption 84,000 years ago. It is shaped by deep surrounding escarpments and three stratovolcanoes on its southern flank. Lake Atitlán is the deepest lake in Central America with a maximum depth of about 340 meters (1,120 ft). Its surface area is 130 sq km (50 sq mi).
In view is the Volcán San Pedro (a.k.a. Volcán Las Yeguas) with an altitude of 3020 meters (9,908 ft).
Chile - Auf dem Villarica (2.847 m)
Villarrica ( /ˌviːəˈriːkə/ VEE-ə-REE-kə) (Spanish: Volcán Villarrica, Mapudungun: Ruka Pillañ) is one of Chile's most active volcanoes, rising above the lake and town of the same name, 750 km (470 mi) south of Santiago. It is also known as Rucapillán, a Mapuche word meaning "Pillan's house". It is the westernmost of three large stratovolcanoes that trend NW-SW obliquely perpendicular to the Andean chain along the Mocha-Villarrica Fault Zone, along with Quetrupillán and the Chilean portion of Lanín, are protected within Villarrica National Park. Guided ascents are popular during summer months.
Villarrica, with its lava of basaltic-andesitic composition, is one of a small number worldwide known to have an active (but in this case intermittent) lava lake within its crater. The volcano usually generates strombolian eruptions with ejection of incandescent pyroclasts and lava flows. Rainfall plus melted snow and glacier ice can cause massive lahars (mud and debris flows), such as during the eruptions of 1964 and 1971.
Villarrica is one of 9 volcanoes currently monitored by the Deep Earth Carbon Degassing Project. The project is collecting data on the carbon dioxide and sulphur dioxide emission rates from subaerial volcanoes.
Villarica stands in the Chilean Central Valley as the westernmost of an alignment of three large stratovolcanoes. The alignment is attributed to the existence of an old fracture in the crust, the North West-South East trending Mocha-Villarrica Fault Zone, the other volcanoes in the chain, Quetrupillán and Lanín, are far less active. The alignment is unusual as it crosses the N-S running Liquiñe-Ofqui Fault, along which several active volcanoes are aligned.
Villarrica covers an area of 400 km2 and has an estimated volume of 250 km3. It contains volcanic caves and about 26 scoria cones. The constant degassing at the lava lake turns the otherwise quite effusive lava more viscous, heightening its explosive potential. Two large ignimbrite layers are visible; the Licán Ignimbrite and the more recent Pucón Ignimbrite.
Villarrica emerged during the Middle Pleistocene and grew forming a large stratocone of similar dimensions to the current edifice. 100,000 years ago during the Valdivia Interglacial the ancestral Villarrica collapsed following an eruption and formed a large elliptical caldera of 6.5 and 4.2 km in diameter. During the Llanquihue glaciation Villarrica produced pyroclastic flow deposits, subglacial andesite lavas and dacite dykes. It collapsed once again 13,700 years ago forming a new smaller caldera, among other pyroclastic flows the Licán Ignimbrite has been related to this event. Beginning with the Licán Ignimbrite, generated just after the last deglaciation, activity continued in similar fashion. The Pucón Ignimbrite was ejected during a minor collapse of the uppermost stratocone 3,700 years ago.
The upper part of Villarrica is permanently covered by snow and has some 40 km2 of glaciers, the largest of which is the Pichillancahue-Turbio Glacier situated on its southeastern flank. Ash from the eruptions can increase the ablation of snow and ice by absorption of solar radiation. Some ash coverings are thicker than 5 cm and insulate the glacier, decreasing ablation instead of enhancing it. Between 1961 and 2003, Villarrica lost 25% of its glaciated surface and the glaciers shrank at an average rate of -0.4 km2 each year.
Villarrica is popular for climbing with guided hikes to the crater from the town of Pucón, but these may be suspended due to cloud or volcanic activity. Helicopter over-flights have been available since 2007. In the winter (July–September) a ski resort operates on the northern slopes.
(Wikipedia)
Villarrica ist ein 2847 m hoher aktiver Vulkan in Chile, der an der Grenze der Regionen Araucanía und Los Ríos liegt. Nördlich des Vulkans befinden sich die Stadt Pucón und der See Lago Villarrica.
Der erste aufgezeichnete Ausbruch datiert aus dem Jahre 1558. 1575 wurde die Stadt Villarrica von einem schweren Erdbeben zerstört, wobei 350 Einwohner starben. Weitere große Ausbrüche folgten 1640 und 1948. 1971 kam es zu einer Schlammlawine, die durch geschmolzenes Eis und heiße Lava erzeugt wurde. Die Schlammlawine (Lahar) zerstörte eine Reihe Häuser, landwirtschaftliche Flächen und Brücken.
In den letzten 500 Jahren wurden über 50 Ausbrüche registriert. Am 3. März 2015 fand eine stärkere Eruption statt. Wegen des Ausbruchs wurden rund 3600 Menschen evakuiert.
Der letzte Ausbruch fand am 23. März 2015 statt.
Der Vulkan Villarrica im Nationalpark Villarrica gehört zu den bekanntesten Touristenzielen in Chile. In den Sommermonaten gehen regelmäßig geführte Touren bis zum Rand des Kraters, die auch für ungeübte Bergsteiger zu bewältigen sind.
2010 war hier noch ein Lavasee aktiv.
(Wikipedia)
Icelandic horses in front of Mountain Hekla (1.488 m) one of the most active stratovolcanoes in the southern part of Iceland. Last eruption in the year of 2000, and 20 eruptions since 874. Sometimes called the "Gateway to Hell"
Contact me at: skarphedinn.thrainsson@gmail.com regarding publication requests.
All rights reserved - Copyright © Skarphéðinn Þráinsson
The Lago de Atitlán is a beautiful lake in the highlands of Guatemala; the water level is at 1562 meters (5,125 ft). The lake basin is volcanic in origin, filling an enormous caldera formed by an eruption 84,000 years ago. It is shaped by deep surrounding escarpments and three stratovolcanoes on its southern flank. Lake Atitlán is the deepest lake in Central America with a maximum depth of about 340 meters (1,120 ft). Its surface area is 130 sq km (50 sq mi).
In view are the Volcán Tolimán (front, right) with an altitude of 3158 meters (10,361 ft) and the Volcán Atitlán (back, left) with an altitude of 3535 meters (11,598 ft).
(video taken by Ian Erickson & provided by the Alaska Volcano Observatory)
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Shishaldin Volcano is a subduction zone stratovolcano on Unimak Island in the Aleutian Islands of Alaska. Minor lava eruptions in the summit crater started on 12 July 2023. Twelve episodes of explosive ash eruptions have occurred since then, on 14 July, 15 July, 18 July, 22-23 July, 25-26 July, 4 August, 14-15 August, 25 August, 5 September, 15 September, 24 to 25 September, and 3 October 2023. This video shows minor lava eruptive activity at Shishaldin's summit on 12 July 2023.
The Aleutian Arc is a subduction zone formed as the Pacific Plate dives underneath the North American Plate (this area is sometimes called the Bering Plate). The diving plate in subduction zones releases water at depth, which causes partial melting of overlying mantle rocks. The low-density melt rises and eventually reaches the surface, forming volcanoes. All subduction zones have volcanoes and frequent seismicity. Volcanoes in such settings tend to have explosive ash eruptions. Rocks and tephra deposits at subduction zone volcanoes are usually intermediate in composition - typically andesitic to dacitic.
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Info. at:
en.wikipedia.org/wiki/Mount_Shishaldin
and
Also known as Koma Kulshan
In 1999, Mount Baker Ski Area, set the world record for recorded snowfall in a single season—1,140 inches (95 feet or 2,896 cm)
Kawah Ijen volcano in East Java contains the world's largest acidic volcanic crater lake, called Kawah Ijen, famous for its turquoise color. The active crater measuring 950x600 m is known for its rich sulphur deposits which are being quarried.
The volcano is one of several active stratovolcanoes constructed over the 20 km wide Ijen caldera, the largest caldera in Java.
Eruptions from Ijen are very hazardous because of the risk of the lake draining to form catastrophic lahars. (volcanodiscovery.com)
Editor's Note: A detail from this larger panoramic image: www.flickr.com/photos/28634332@N05/4554348391/
Volcanoes near Usulutan, El Salvador are featured in this image photographed by an Expedition 23 crew member on the International Space Station. The Pacific coastline of much of Central America is marked by a line of active and quiescent volcanoes known to geologists as the Central American Volcanic Arc, or CAVA. The volcanoes result from the upward movement of magma generated along the subduction zone between the Cocos and Caribbean tectonic plates; frequent earthquakes also occur along the plate boundary. This photograph includes four stratovolcanoes -- a type of volcano associated with active subduction zones -- located near the midpoint of the CAVA in El Salvador. Scientists believe while all of the volcanoes shown here have been active during the Holocene Epoch (approximately 10,000 years ago to present), only the 2,130-meter-high San Miguel (also known as Chaparrastique) has been active during historical times. The most recent activity of San Miguel was a minor gas and ash emission in 2002. The steep conical profile and well-developed summit crater are evident at left, along with dark lava flows produced by San Miguel. Immediately to the northwest the truncated summit of Chinameca volcano (also known as El Pacayal) is marked by a two-kilometer-wide caldera, formed when the volcano's magma chamber was emptied by a powerful eruption followed by collapse of the chamber's roof. Like its neighbor San Miguel, Chinameca's slopes host coffee plantations. Moving to the southwest the eroded cone of El Tigre volcano is visible. According to scientists, El Tigre volcano formed during the Pleistocene Epoch (1.8 million to approximately 10,000 years ago) and is likely the oldest of the stratovolcanoes depicted in the image. Usulutan volcano is located directed to the southwest of El Tigre. While the flanks of Usulutan have been dissected by stream flow it still retains a summit crater that is breached on the eastern side. Several urban areas - recognizable as light gray to white regions contrasting with green vegetation and tan fallow agricultural fields - are located in the vicinity of these volcanoes, including Usulutan (upper right) and Santiago de Mara (lower right).
Image/caption credit: NASA
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ISS038-E-025895 (5 Jan. 2014) --- Bazman volcano in Iran is featured in this image photographed by an Expedition 38 crew member on the International Space Station. Bazman volcano is located in a remote southern region within the Bazman Protected Area of Sistan and Baluchestan Provinces. While the volcano has the classic cone shape associated with stratovolcanoes, it is also heavily dissected by channels that extend downwards from the 3,490-meter-above-sea-level summit. This radial drainage pattern - looking similar to the spokes of a bicycle wheel - is readily observed in this photograph. Such patterns can form around high, symmetric peaks when water runoff and erosion is not constrained by the resistance of geologic materials or barriers to flow, leading to essentially even distribution of water runoff channels around the central peak. While there is no historical record of volcanism at Bazman, and no geologic record of eruptive activity within the past 10,000 years, some fumarolic activity - gas and steam emissions - have been reported, according to the Smithsonian Institution National Museum of Natural History's Global Volcanism Program. The summit of the volcano is marked by a well-formed explosion crater, and lava cones formed on the flanks of the main volcano are associated with well-preserved lava flows-a particularly striking example is visible on the north flank of Bazman at center. Together, these observations and features are suggestive that Bazman may be a dormant, rather than extinct, volcano.
Kamchatka volcanoes are featured in this image photographed by an Expedition 25 crew member on the International Space Station. This striking photograph features several snow-covered volcanoes located on the Kamchatka Peninsula of the Russian Federation, as seen from the orbital perspective of the International Space Station (ISS). This image also illustrates one of the unique attributes provided by the ISS -- the ability to view Earth landscapes at an angle, rather than the "straight down" view typical of many orbital satellite-based sensors. This oblique view, together with shadows cast by the volcanoes and other mountains provides perspective about the setting and a sense of topography of the region, especially highlighting the symmetrical cones of Kronotsky (center) and Kizimen (top right) stratovolcanoes. Kizimen Volcano last erupted in 1928, while Kronotsky Volcano-one of the largest on the peninsula-last erupted in 1923. Schmidt Volcano, located to the north of Kronotsky, has the morphology of a shield volcano and is not known to have erupted during the period of historical record. To the south of Kronotsky is Krasheninnikov Volcano, comprised of two overlapping stratovolcanoes that formed within an earlier caldera. Scientists believe Krasheninnikov may have last erupted in 1550. The two summit craters of the stratovolcanoes are clearly visible in this image (lower left). Lake Kronotsky (left) is Kamchatka's largest lake; it was formed when lava flows from Kronotsky Volcano dammed the Listvenichnaya River. The Kamchatka Peninsula lies along the so-called "Ring of Fire" in the Pacific Ocean. The Ring of Fire is characterized by the presence of active volcanoes and frequent earthquakes; these are associated with the many active subduction and transform boundary zones that ring the Pacific tectonic plate. According to scientists, there are currently 114 volcanoes identified on the Kamchatka Peninsula that have erupted during the Holocene Epoch (approximately 12,000 years ago to the present).
Image credit: NASA
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The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
A 3 frame panorama of a Fata Morgana Mirage of Mount Illiamna, one of our local recently active Stratovolcanoes, here in Southcentral Alaska. Mount Illiamna's summit is 8,990 feet above sea level.
This is exciting to me, as it is the first 3 frame mirage panorama that may by printable in a very large size. Mirages are the most difficult panoramas to stitch together I have encountered so far.
Best viewed large on black.
The Ijen volcano complex is a group of stratovolcanoes inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor (http://en.wikipedia.org/wiki/Ijen).
The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding Valley to get paid.
The active crater at Kawah Ijen has a diameter of 722 metres (2,369 ft) and a surface area of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
The lake is recognised as the largest highly acidic crater lake in the world.
Mount Fuji, Japan is featured in this image photographed by an Expedition 19 crew member on the International Space Station. The 3,776 meters high Mount Fuji volcano, located on the island of Honshu in Japan, is one of the world's classic examples of a stratovolcano. The volcano's steep, conical profile is the result of numerous interlayered lava flows and explosive eruption products -- such as ash, cinders, and volcanic bombs -- building up the volcano over time. The steep profile is possible because of the relatively high viscosity of the volcanic rocks typically associated with stratovolcanoes. This leads to thick sequences of lava flows near the eruptive vent that build the cone structure, rather than low viscosity flows that spread out over the landscape and build lower-profile shield volcanoes. According to scientists, Mount Fuji, or Fuji-san in Japan, is actually comprised of several overlapping volcanoes that began erupting in the Pleistocene Epoch (1.8 million to approximately 10,000 years ago). Scientists believe that the currently active volcano, known as Younger Fuji, began forming approximately 11,000 to 8,000 years ago. The most recent explosive activity occurred in 1707, creating Hoei Crater on the southeastern flank of the volcano (center). This eruption deposited ash on Edo (present-day Tokyo) located 95 kilometers to the northeast. While there have been no further eruptions of Mount Fuji, steam was observed at the summit during 1780--1820, and the volcano is considered active.
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The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 (Rp 50,000 - Rp 75,000) per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding valley to get paid.
Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid
Mt. Saint Helens, which we climbed earlier in the season.
#UpperLeftUSA #Mountaineering #Mountains #GregoryPacks #Washington #StratoVolcanoes #GetOutside #Backpacking
The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding Valley to get paid.
The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 (Rp 50,000 - Rp 75,000) per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding valley to get paid.
Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid
Villarrica is one of Chile's most active volcanoes, rising above the lake and town of the same name. The volcano is also known as Rucapillán, a Mapuche word meaning "House of the Pillán". It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain along the Gastre Fault. Set within Villarrica National Park, ascents of the volcano are popular with several guided ascents reaching the top during summer.
The Lago de Atitlán is a beautiful lake in the highlands of Guatemala; the water level is at 1562 meters (5,125 ft). The lake basin is volcanic in origin, filling an enormous caldera formed by an eruption 84,000 years ago. It is shaped by deep surrounding escarpments and three stratovolcanoes on its southern flank. Lake Atitlán is the deepest lake in Central America with a maximum depth of about 340 meters (1,120 ft). Its surface area is 130 sq km (50 sq mi).
The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding Valley to get paid.
Taken along the summit rim trail of Mount Vesuvius. Looking at a portion of the interior of the Gran Cono crater.
When I was a child, my father spent hours, with Chicago Motor Club maps spread out before him, planning a family trip to the Pacific Northwest and the Cascade Range. In his own childhood he'd been to Crater Lake in Oregon and for good reason thought it the most beautiful place on Earth.
While in my early years we did get to many splendid places in the West, including the Yellowstone Caldera and the Canadian Rockies, we never quite made it all the way to the Cascade peaks that form the magnificent (and dangerous) continental volcanic arc a little inboard from the subducting Juan de Fuca Plate. As a matter of fact, I didn't get to them by myself until my middle adulthood, long after I'd been to the tops of Vesuvius, Etna, and Stromboli.
Of that Italian triad, Vesuvius was my first ascent. And it was the first place I'd ever visited that seemed to be chronologically unhitched from the landscape below and around it.
Whether they're currently erupting or not, the world's great volcanic summits invest one with the feeling that the planet itself is still very young and forming. It's an eerie thing to suddenly find oneself in an early chapter of the Earth's creation—the Hadean, perhaps, or the dawn of the Eoarchean, some 4 Ga before the birth of our species.
That makes it all the more ironic that the geology here is actually remarkably young. This fact is made abundantly clear in one of my main sources for this series, "Volcanic Evolution of the Somma-Vesuvius Complex (Italy)," Sbrana et al., Journal of Maps, January 2020.
If I'm interpreting one of that article's illustrations correctly, the upper portion of the crater wall shown in the photo above was almost all produced in the 1944 eruption, during the Allies' torturous advance up the Italian peninsula. Only the lowest quarter of the visible strata are older; and they just date to the period 1913-1930.
Incidentally, notice that I used the term strata for rock units that are obviously igneous. If you're someone who's taken a single geology course, perhaps as a 100-level science elective in college, you probably think that strata (synonymous with layers and beds) are the sole intellectual property of sedimentary rocks.
So it appears I'm violating a basic understanding uttered by countless Earth-science instructors. But it turns out that what they told you is something I call a beginner's truth—an educatively helpful fact that is partly abrogated as one gains additional experience.
It's true that a nice set of stacked beds is an excellent way to identify sedimentary rocks. But in composite volcanoes like Vesuvius, also known as stratovolcanoes for good reason, you'll see striking patterns of alternating layers, too. In this case, though, they're not made of sandstone, limestone, or some other clastic or chemically precipitated type. Instead, they're a succession of tephra (ash, lapilli, pumice, and other ejected particles) and lava flows that poured onto the surface while still in a liquid state.
In Part 1 of this set, I discussed the petrology and predominant rock types of Vesuvius' more recently erupted material. But in this post, instead of focusing on the arcanities of tephrite, phonolite, and their intergradations, let's just identify what beds are lava and which are the tephra.
Fortunately, this is one of the best places in the world to see the inner structure of a stratovolcano: the crater is about 500 m (1,640 ft) wide and 300 m (984 ft) deep. And its almost-vertical walls are nothing less than the opened pages of a geology textbook.
First of all, the sunlit, reddish-brown material blanketing the rim is mostly tephra. When you actually walk on it, it has a crunchy, granular to dusty texture.
Farther down the wall, in the shade, the tephra takes on a darker aspect. In contrast, the lava strata are lighter-toned and more massive (thicker). See how many different layers you can actually count. Each bed represents its own geologic story worthy of remembrance.
The other photos and descriptions of this series can be found in my Integrative Natural History of Mount Vesuvius & the Gulf of Naples album.
The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding Valley to get paid.
The active crater at Kawah Ijen has a diameter of 722 metres (2,369 ft) and a surface area of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
The lake is recognised as the largest highly acidic crater lake in the world.
The Lago de Atitlán is a beautiful lake in the highlands of Guatemala; the water level is at 1562 meters (5,125 ft). The lake basin is volcanic in origin, filling an enormous caldera formed by an eruption 84,000 years ago. It is shaped by deep surrounding escarpments and three stratovolcanoes on its southern flank. Lake Atitlán is the deepest lake in Central America with a maximum depth of about 340 meters (1,120 ft). Its surface area is 130 sq km (50 sq mi).
In view is the Volcán San Pedro (a.k.a. Volcán Las Yeguas) with an altitude of 3020 meters (9,908 ft).
Stratovolcanoes are tall conical mountains composed of lava flows and other ejecta in alternate layers, the strata that give rise to the name. Stratovolcanoes are also known as composite volcanoes, created from several structures during different kinds of eruptions. Strato/composite volcanoes are made of cinders, ash and lava. Cinders and ash pile on top of each other, then lava flows on top and dries and then the process begins again.
The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
Gorely - is a volcano located in the southern part of Kamchatka Peninsula, Russia. It consists of five overlapping stratovolcanoes and is one of the most active in southern Kamchatka.
Gorely is a large, long-lived shield-type volcano that is currently in an eruptive phase
Mt. Jefferson as seen from Triangulation Peak on a hot summer afternoon - with Xerophyllum tenax (Beargrass)
Teide Volcano on the Canary Islands of Spain is featured in this image photographed by an Expedition 20 crew member on the International Space Station. This detailed photograph features two stratovolcanoes - Pico de Teide and Pico Viejo - located on Tenerife Island, part of the Canary Islands of Spain. Stratovolcanoes are steep-sided; typically conical structures formed by interlayered lavas and fragmented rock material from explosive eruptions. Pico de Teide has a relatively sharp peak, whereas an explosion crater forms the summit of Pico Viejo. The two stratovolcanoes formed within an even larger volcanic structure known as the Las Canadas caldera - a large collapse depression typically formed when a major eruption completely empties the underlying magma chamber of a volcano. The last eruption of Teide occurred in 1909. NASA scientists point out sinuous flow levees marking individual lava flows. The scientists consider the flow levees as perhaps the most striking volcanic features visible in the image. Flow levees are formed when the outer edges of a channelized lava flow cool and harden while the still-molten interior continues to flow downhill - numerous examples radiate outwards from the peaks of both Pico de Teide and Pico Viejo. Brown to tan overlapping lava flows and domes are visible to the east-southeast of the Teide stratovolcano. Increased seismicity, carbon dioxide emissions, and fumarolic activity within the Las Canadas caldera and along the northwestern flanks of the volcano were observed in 2004. Monitoring of the volcano to detect renewal of activity is ongoing.
Image Credit: NASA
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This photograph, featuring a landscape in the central Andes mountains near the Chile/Argentina border dominated by numerous volcanoes and associated landforms, was photographed by an Expedition 24 crew member on the International Space Station. Layers of older sedimentary rocks are visible to the southeast (upper right). Many of the volcanic cones show grooves eroded by water to form gullies. Such erosion has occurred since the host volcano was built up, indicating that most volcanoes in this view have been inactive for centuries or millennia. A few volcanoes exhibit much less erosion, and even show tongues of recent, dark lava flows (top left). According to scientists, two of these volcanoes, Cerro el Condor and Peinado have likely erupted within approximately the last 12,000 years (the Holocene Epoch). Also visible in the image is the world's highest active volcano, Nevado Ojos del Salado, with a summit at 6,887 meters above sea level. The most recent confirmed eruption of this volcano has been dated to 700 (approximately 300 years), but minor eruptive activity may have occurred as recently as 1993. Stratovolcanoes such as Cerro el Condor, Peinado, and Nevado Ojos del Salado are formed partly by buildup of lava flows and partly by buildup of explosively vented material dropping back down onto the surface. One type of material associated with explosive eruptions is welded tuff, which is formed by molten and fragmented rock that accumulates on the ground and later solidifies. A large tuff sheet is visible at top left. Formed very rapidly, these sheets have been termed "instant landscapes." So active has the Andean volcanic system been that the origin of many of the tuffs in the Andes cannot be pinpointed since source vents have been overprinted by subsequent volcanic events. The volcanic landscape also shows that the erosive work of rivers—and glaciers repeatedly in the recent past—is slower than the opposite processes of the upward building of the volcanoes. The bright blue, nearly 7-kilometer-long lake near the center of the image is known as Laguna Verde. This and other less obvious lakes indicate that water (snowmelt or direct precipitation) is unable to reach the sea, but is rather impounded in the depressions between the volcanic edifices.
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It feels like Spring, and we all welcome the more extended daylight. As we went into Glennallen yesterday, the Wrangell Mountains were out in full view. From left to right: Mount Sanford, Mount Drum, and Mount Wrangell. This is one view I never get tired of seeing.
The Ijen volcano complex is a group of stratovolcanoes, in East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name of this volcano resembles that of a different volcano, Mount Merapi in central Java, also known as Gunung Merapi; there is also a third volcano named Marapi in Sumatra. The name "Merapi" means "fire" in the Indonesian language.
West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acid crater lake. The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is low-paid and very onerous. Workers earn around $5.50-$8.30 (Rp 50,000 - Rp 75,000) per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Pultuding valley to get paid.[1]
Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).
In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid
Small explosive eruption of Mt. Pinatubo on 1 August 1991. (original photo taken by T.J. Casadevall; public domain image provided by the United States Geological Survey)
Mt. Pinatubo’s summer 1991 eruption was the largest on Earth since 1912. Pinatubo's big eruption is also famous for having been successfully predicted by American volcanologists. The prediction and subsequent evacuation saved thousands of lives.
Located near the western margin of Luzon Island in the northern Philippines, Mt. Pinatubo is one of several subduction zone stratovolcanoes in the Luzon Volcanic Arc. Published information indicates that Pinatubo is 35,000+ years old and is composed principally of dacitic and andesitic rocks.
The mid-June 1991 eruptions from Pinatubo blanketed ash, pumiceous lapilli, and pumice over the surrounding countryside, including two American military bases (Clark and Subic Bay).
The photo shows a small explosive eruption on 1 August 1991. The main eruption occurred 1.5 months earlier, on 15 June 1991.
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See info. at:
Newhall & Punongbayan (1996) - Fire and Mud, Eruptions and Lahars of Mount Pinatubo, Philippines. Quezon City & Seattle & London. Philippine Institute of Volcanology and Seismology & University of Washington Press. 1126 pp.
Volcanoes near Usulutan, El Salvador are featured in this image photographed by an Expedition 23 crew member on the International Space Station. The Pacific coastline of much of Central America is marked by a line of active and quiescent volcanoes known to geologists as the Central American Volcanic Arc, or CAVA. The volcanoes result from the upward movement of magma generated along the subduction zone between the Cocos and Caribbean tectonic plates; frequent earthquakes also occur along the plate boundary. This photograph includes four stratovolcanoes -- a type of volcano associated with active subduction zones -- located near the midpoint of the CAVA in El Salvador. Scientists believe while all of the volcanoes shown here have been active during the Holocene Epoch (approximately 10,000 years ago to present), only the 2,130-meter-high San Miguel (also known as Chaparrastique) has been active during historical times. The most recent activity of San Miguel was a minor gas and ash emission in 2002. The steep conical profile and well-developed summit crater are evident at left, along with dark lava flows produced by San Miguel. Immediately to the northwest the truncated summit of Chinameca volcano (also known as El Pacayal) is marked by a two-kilometer-wide caldera, formed when the volcano's magma chamber was emptied by a powerful eruption followed by collapse of the chamber's roof. Like its neighbor San Miguel, Chinameca's slopes host coffee plantations. Moving to the southwest the eroded cone of El Tigre volcano is visible. According to scientists, El Tigre volcano formed during the Pleistocene Epoch (1.8 million to approximately 10,000 years ago) and is likely the oldest of the stratovolcanoes depicted in the image. Usulutan volcano is located directed to the southwest of El Tigre. While the flanks of Usulutan have been dissected by stream flow it still retains a summit crater that is breached on the eastern side. Several urban areas - recognizable as light gray to white regions contrasting with green vegetation and tan fallow agricultural fields - are located in the vicinity of these volcanoes, including Usulutan (upper right) and Santiago de Mara (lower right).
Image/caption credit: NASA
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