Portal:Mountains/Selected article

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Portal:Mountains/Selected article/1

Cerro Azul (blue hill in Spanish), sometimes referred to as Quizapu, is an active stratovolcano in the Maule Region of central Chile, immediately south of Descabezado Grande. Part of the South Volcanic Zone of the Andes, its summit is 3,788 meters (12,428 ft) above sea level, and is capped by a summit crater that is 500 meters (1,600 ft) wide and opens to the north. Beneath the summit, the volcano features numerous scoria cones and flank vents.

Cerro Azul is responsible for several of South America's largest recorded eruptions, in 1846 and 1932. In 1846, an effusive eruption formed the vent at the site of present-day Quizapu crater on the northern flank of Cerro Azul and sent lava flowing down the sides of the volcano, creating a lava field 8–9 square kilometers (3–3.5 square miles) in area. Phreatic and Strombolian volcanism between 1907 and 1932 excavated this crater. In 1932, one of the largest explosive eruptions of the 20th century occurred at Quizapu Crater and sent 9.5 cubic kilometers (2.3 cu mi) of ash into the atmosphere. The volcano's most recent eruption was in 1967.

The South Volcanic Zone has a long history of eruptions and poses a threat to the surrounding region. Any volcanic hazard—ranging from minor ashfalls to pyroclastic flows—could pose a significant risk to humans and wildlife. Despite its inactivity, Cerro Azul could again produce a major eruption; if this were to happen, relief efforts would probably be quickly organized. Teams such as the Volcano Disaster Assistance Program (VDAP) are prepared to effectively evacuate, assist, and rescue people threatened by volcanic eruptions.

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Mauna Kea is a Volcano on the island of Hawaii. Standing 4,205 m (13,796 ft) above sea level, its peak is the highest point in the state of Hawaii. However, much of the mountain is under water. Mauna Kea is about a million years old, and has passed the most active shield stage of life hundreds of thousands of years ago. In its current post-shield state, its lava is more viscous, resulting in a steeper profile. Late volcanism has also given it a much rougher appearance than its neighboring volcanoes; contributing factors include the construction of cinder cones, the decentralization of its rift zones, the glaciation on its peak, and the weathering effects of the prevailing trade winds. Mauna Kea last erupted 4,000 to 6,000 years ago.

In Hawaiian mythology, the peaks of the island of Hawaii are sacred, and Mauna Kea is the most sacred of all. An ancient law allowed only high-ranking tribal chiefs to visit its peak. Ancient Hawaiians living on the slopes of Mauna Kea relied on its extensive forests for food, and quarried the dense volcano-glacial basalts on its flanks for tool production. When Europeans arrived in the late 18th century, settlers introduced cattle, sheep and game animals, many of which became feral and began to damage the mountain's ecology. Mauna Kea can be ecologically divided into three sections: an alpine climate at its summit, a Sophora chrysophylla–Myoporum sandwicense (or māmane–naio) forest on its flanks, and an Acacia koa–Metrosideros polymorpha (or koa–ʻōhiʻa) forest, now mostly cleared by the former sugar industry, at its base. In recent years, concern over the vulnerability of the native species has led to court cases that have forced the Hawaii Department of Land and Natural Resources to eradicate all feral species on the mountain.

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Mauna Kea is the largest volcano on Earth in terms of volume and area covered, and one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaiʻi in the Pacific Ocean. It is an active shield volcano, with a volume estimated at approximately 18,000 cubic miles (75,000 km³), although its peak is about 120 feet (37 m) lower than that of its neighbor, Mauna Kea. The Hawaiian name "Mauna Loa" means "Long Mountain". Lava eruptions from Mauna Loa are silica-poor, and very fluid; eruptions tend to be non-explosive and the volcano has relatively shallow slopes.

Mauna Loa has probably been erupting for at least 700,000 years, and may have emerged above sea level about 400,000 years ago. Its most recent eruption occurred from March 24, 1984, through April 15, 1984. No recent eruptions of the volcano have caused fatalities, but eruptions in 1926 and 1950 destroyed villages, and the city of Hilo is partly built on lava flows from the late 19th century. In view of the hazards it poses to population centers, Mauna Loa is part of the Decade Volcanoes program, which encourages studies of the most dangerous volcanoes. Mauna Loa has been intensively monitored by the Hawaiian Volcano Observatory since 1912. Observations of the atmosphere are undertaken at the Mauna Loa Observatory, and of the Sun at the Mauna Loa Solar Observatory, both located near its summit. Hawaii Volcanoes National Park covers the summit and the southeastern flank of the volcano, including a separate volcano, Kīlauea.

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The Metacomet Ridge of southern New England, United States, is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and communities of plants considered rare or endangered. An important recreation resource located within 10 miles (16 km) of a population corridor of over 2.5 million people, the ridge is home to four long distance hiking trails and over a dozen parks and recreation areas, including several state and nationally recognized historic sites. Because of its natural, historic, and recreational value, the ridge has been the focus of ongoing conservation efforts involving municipal, state, and national agencies as well as nearly two dozen non-profit organizations.

Metacomet Ridge extends from New Haven and Branford, Connecticut on Long Island Sound, through the Connecticut River Valley region of Massachusetts, to northern Franklin County, 2 miles (3.2 km) short of the Vermont and New Hampshire borders, a distance of 100 miles (160 km). Younger and geologically distinct from the nearby Appalachian Mountains and surrounding uplands, the ridge is composed of volcanic basalt, known as traprock, and sedimentary rock in faulted and tilted layers many hundreds of feet thick. In most but not all cases, the basalt layers are dominant, prevalent, and exposed. Although only 1,200 feet (370 m) above sea level at its highest, with an average summit elevation of 725 feet (221 m), the Metacomet Ridge rises dramatically from much lower valley elevations, making it a prominent landscape feature.

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The Mono–Inyo Craters is a volcanic chain of craters, domes and lava flows in Eastern California that stretches 25 miles (40 km) from the northwest shore of Mono Lake to the south of Mammoth Mountain. The Mono Lake Volcanic Field forms the northernmost part of the chain and consists of two volcanic islands in the lake and one cinder cone volcano on its northwest shore. Most of the Mono Craters, which make up the bulk of the northern part of the Mono–Inyo chain, are phreatic (steam explosion) volcanoes that have since been either plugged or over-topped by rhyolite domes and lava flows. The Inyo Craters form much of the southern part of the chain and consist of phreatic explosion pits, and rhyolitic lava flows and domes. The southernmost part of the chain consists of fumaroles and explosion pits on Mammoth Mountain and a set of cinder cones south of the mountain; the latter are called the Red Cones.

Multiple eruptions from 40,000 to 600 years ago created the Mono Craters, and eruptions 5,000 to 500 years ago formed the Inyo Craters. Lava flows 5,000 years ago built the Red Cones, and explosion pits on Mammoth Mountain were excavated in the last 1,000 years. These eruptions most likely originated from small magma bodies rather than from a single, large magma chamber like the one that produced the massive Long Valley Caldera eruption 760,000 years ago. During the past 3,000 years, eruptions have occurred every 250 to 700 years.

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The Mount Cayley volcanic field is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the Cayley volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, the largest and most persistent volcano, located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.

Eruptions along the length of the field began between 1.6 and 5.3 million years ago. At least 23 eruptions have occurred throughout its eruptive history. This volcanic activity ranged from effusive to explosive, with magma compositions ranging from basaltic to rhyolitic. Because the Mount Cayley volcanic field has a high elevation and consists of a cluster of mostly high altitude, non-overlapping volcanoes, subglacial activity is likely to have occurred under less than 800 m (2,600 ft) of glacial ice. The style of this glaciation promoted meltwater escape during eruptions. The steep profile of the volcanic field and its subglacial landforms support this hypothesis. As a result, volcanic features in the field that interacted with glacial ice lack rocks that display evidence of abundant water during eruption, such as hyaloclastite and pillow lava.

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Portal:Mountains/Selected article/7

Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who made a survey of the area in the late 18th century. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. This volcano is well known for its ash explosions and pyroclastic flows. As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted.

Mount St. Helens is most famous for its catastrophic 1980 eruption, which was the deadliest and most economically destructive volcanic event in the history of the United States. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles (24 km) of railways, and 185 miles (298 km) of highway were destroyed. A massive debris avalanche triggered by an earthquake measuring 5.1 on the Richter scale, caused an eruption, reducing the elevation of the mountain's summit from 9,677 ft (2,950 m) to 8,365 ft (2,550 m) and replacing it with a 1-mile (1.6 km)-wide horseshoe-shaped crater. The earthquake was caused by a sudden surge of magma from the Earth's mantle. The debris avalanche was up to 0.7 cubic miles (2.9 km³) in volume.

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Portal:Mountains/Selected article/8

Mount Tambora is an active stratovolcano, also known as a composite volcano, on the island of Sumbawa, Indonesia. Sumbawa is flanked both to the north and south by oceanic crust, and Tambora was formed by the active subduction zone beneath it. This raised Mount Tambora as high as 4,300 m (14,100 ft), making it one of the tallest peaks in the Indonesian archipelago. After a large magma chamber inside the mountain filled over the course of several decades, volcanic activity reached a historic climax before erupting in April 1815.

The 1815 eruption is rated 7 on the volcanic explosivity index, the only such eruption since the Lake Taupo eruption in about 180 AD. With an estimated ejecta volume of 160 km³ (38 cu mi), Tambora's 1815 outburst was the largest volcanic eruption in recorded history. The explosion was heard on Sumatra island, more than 2,000 km (1,200 mi) away. Heavy volcanic ash falls were observed as far away as Borneo, Sulawesi, Java and Maluku islands. Most deaths from the eruption were from starvation and disease, as the eruptive fallout ruined agricultural productivity in the local region. The eruption killed at least 71,000 people and created global climate anomalies that included the phenomenon known as "volcanic winter": 1816 became known as the "Year Without a Summer". Agricultural crops failed and livestock died in much of the Northern Hemisphere, resulting in the worst famine of the 19th century.

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Portal:Mountains/Selected article/9

The Nevado del Ruiz is a volcano located on the border of the departments of Caldas and Tolima in Colombia, about 129 kilometers (80 mi) west of the capital city Bogotá. It is a stratovolcano, composed of many layers of lava alternating with hardened volcanic ash and other pyroclastic rocks. Nevado del Ruiz has been active for about two million years, since the early Pleistocene or late Pliocene epoch, with three major eruptive periods. The current volcanic cone formed during the present eruptive period, which began 150,000 years ago. The volcano is part of Los Nevados National Natural Park, which also contains several other volcanoes. The summit of Nevado del Ruiz is covered by large glaciers, although these have retreated significantly since 1985 because of atmospheric warming.

The Nevado del Ruiz usually generates Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows. These eruptions often cause massive lahars (mud and debris flows), which pose a threat to human life and the environment. On November 13, 1985, a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 23,000 deaths. This event later became known as the Armero tragedy—the deadliest lahar in recorded history. Similar but less deadly incidents occurred in 1595 and 1845, consisting of a small explosive eruption followed by a large lahar. The volcano continues to pose a threat to the nearby towns and villages, and it is estimated that up to 500,000 people could be at risk from lahars from future eruptions.

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Portal:Mountains/Selected article/10

The Volcano is a small cinder cone in the Boundary Ranges of the Coast Mountains in northwestern British Columbia, Canada. It is located approximately 60 km (40 mi) northwest of the small community of Stewart near the head of Lava Fork. With a summit elevation of 1,330 m (4,360 ft) and a topographic prominence of 311 m (1,020 ft), it rises above the surrounding rugged landscape on a remote mountain ridge that represents the northern flank of a glaciated U-shaped valley.

Lava Fork volcano is associated with a small group of related volcanoes called the Iskut-Unuk River Cones. This forms part of the much larger Northern Cordilleran Volcanic Province, which extends from the Alaska–Yukon border to near Prince Rupert, British Columbia. Eruptive activity at The Volcano is relatively young compared to most other volcanoes in the Northern Cordilleran Volcanic Province. Geologic studies have shown that The Volcano and its eruptive products were emplaced in the past 400 years; this is well after the last glacial period, which ended about 10,000 years ago.

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Portal:Mountains/Selected article/11

Amak Volcano is a basaltic andesite stratovolcano in the Aleutian Islands of Alaska, USA, 618 miles (995 km) from Anchorage. It is located on the eponymous island, 31 miles (50 km) from Frosty Volcano, near the edge of the Alaskan Peninsula's western flank. Only boats are allowed to access the island, and only with a certain permit.

Blocky (dotted with flat blocks of minerals and crystals) lava flows stream from its summit to its flanks. Three historical eruptions have taken place – two within the 18th century, the first from 1700–1710, and the latter in 1796. The earliest prehistoric eruption was believed to have taken place between 3050 and 2050 BCE.

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Portal:Mountains/Selected article/12

Ben Nevis is the highest mountain in the British Isles. It is located at the western end of the Grampian Mountains in the Lochaber area of the Scottish Highlands, close to the town of Fort William. As is common for many Scottish mountains, it is known both to locals and visitors as simply The Ben. It attracts an estimated 100,000 ascents a year, around three-quarters of which are made using the well-constructed Pony Track from Glen Nevis on the south side of the mountain. For climbers and mountaineers the main attraction lies in the 700-metre (2,300 ft) high cliffs of the north face; among the highest cliffs in the United Kingdom, they harbour some classic scrambles and rock climbs of all difficulties, and are one of the principal locations in the UK for ice climbing.

The summit, at 1,344 metres (4,409 ft) above sea level, features the ruins of an observatory, which was permanently staffed between 1883 and 1904. The meteorological data collected during this period are still important for understanding Scottish mountain weather. C. T. R. Wilson was inspired to invent the cloud chamber after a period spent working at the observatory.

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Gerlachovský štít (translated into English as Gerlach Peak) is the highest peak in the High Tatras, in Slovakia, and in the Carpathian mountain chain. Until the Treaty of Trianon it was Hungary's highest point. Usually listed at 2,655 metres (8,711 ft) above sea level, its exact elevation is actually 0.6 metres (2.0 ft) lower. The pyramidal shape of the massif is marked by a huge cirque. Gerlachovský štít has played a symbolic role in the eyes of the rulers and populations of several Central European nations, to the point that between the 19th and mid–20th century, it had four different names with six name reversals. It managed to be the highest mountain of the Kingdom of Hungary, and of the countries of Czechoslovakia and Slovakia within the span of only about two decades.

Gerlachovský štít shares its geology and ecology with the rest of the High Tatras, but provides a worthwhile environment for biologists as the highest ground anywhere in Europe north of the parallel linking approximately Munich, Salzburg, and Vienna. The mountain used to be particularly treasured as the loftiest point to climb to by Czechs, eastern Germans, Hungarians, Poles, and Slovaks during the period of restricted travel in the 20th century. It continues to attract its share of visitors although the local authorities have been continually adding new restrictions on access.

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Glacier Peak is the most isolated of the five major stratovolcanoes (composite volcanoes) of the Cascade Volcanic Arc in Washington. Located in the Glacier Peak Wilderness, the volcano is not easily discernible from any heavily populated area; as a result the volcano is largely understudied and not as much is known about it compared to other volcanoes in the area. Since the most recent ice age, it has produced some of largest and most explosive eruptions in the state. The mountain has erupted explosively during each of five episodes in the past 3,000 years. The volcano formed during the Pleistocene epoch, about 1 million years ago. Glacier Peak is one of the most active of Washington's volcanoes. When continental ice sheets retreated from the region, Glacier Peak began to erupt regularly. It has erupted repeatedly during at least six periods; two of these incidents have been among the largest in Washington.

In their history, local Native Americans have recognized Glacier Peak and other Washington volcanoes. It is a part of their history and story-telling. When foreign explorers reached the region, they learned basic information about surrounding landforms, but did not learn that Glacier Peak was a volcano. Positioned in Snohomish County, the volcano is only 70 miles (110 km) northeast of Seattle – closer to that city than any volcano except Mount Rainier. However, unlike Mount Rainier, Glacier Peak is rather short, and is barely visible from a distance.

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Hualālai is a dormant shield volcano on the island of Hawaiʻi in the Hawaiian Islands. It is the third-youngest and the third most active of the five volcanoes that form the island of Hawaiʻi, following Kīlauea and the much larger Mauna Loa, and also the westernmost. Its peak is 8,271 feet (2,521 m) above sea level.

Hualālai is estimated to have risen above sea level about 300,000 years ago. Despite maintaining a very low level of activity since its last eruption in 1801, Hualālai is still considered active, and is expected to erupt again some time within the next century. The volcano has been inhabited for centuries by Hawaiian natives, predating recorded history. The ecologically important volcano is home to many rare species and contains several nature reserves near the summit.

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Huangshan is a mountain range in southern Anhui province in eastern China. The range composed of material that was uplifted from an ancient sea during the Mesozoic era, 100 million years ago; the mountains themselves were carved by glaciers during the Quaternary. Vegetation on the range is thickest below 1,100 meters (3,600 ft), with trees continuing until 1,800 meters (5,900 ft).

The area is well known for its scenery, sunsets, peculiarly shaped granite peaks, Huangshan Pine trees, and views of the clouds from above. Huangshan is a frequent subject of traditional Chinese paintings and literature, as well as modern photography. It is a UNESCO World Heritage Site, and one of China's major tourist destinations.

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Joppenbergh Mountain is a nearly 500-foot (150 m) mountain in Rosendale Village in Ulster County, New York. It was named after Rosendale's founder, Jacob Rutsen, and mined throughout the late 19th century for dolostone that was used for the manufacture of natural cement. There was a large cave-in on December 19, 1899, that destroyed mining equipment and collapsed shafts within the mountain. Though it was feared that several workers had been killed, the collapse happened during lunch, and all the miners were outside, eating. Since the collapse, the mountain has experienced shaking and periodic rockfalls.

During the late 1930s, Joppenbergh became the site of several ski jumping competitions, which continued until the early 1940s. The mountain's slope was coated with borax in July 1937 for a summer tournament. Skiing stopped until the 1960s, when a new slope was built, and competitions were held until 1971. The town leased a tract of land near the mountain in 2004 to build a municipal parking lot. Joppenbergh, the municipal parking lot, and an adjoining park were put up for sale in 2009. In March 2011, the Open Space Institute offered to purchase the entire 117-acre (47 ha) property and sell it to the town. Rosendale's town board initially agreed to the deal, but a review of the town's expenses determined that the money budgeted for the purchase had already been spent.