A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Mount Vesuvius is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about 9 km (5.6 mi) east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc. Vesuvius consists of a large cone partially encircled by the steep rim of a summit caldera, resulting from the collapse of an earlier, much higher structure.
Nevado del Ruiz, also known as La Mesa de Herveo is a volcano on the border of the departments of Caldas and Tolima in Colombia, about 129 km (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. Volcanic activity at Nevado del Ruiz began about two million years ago, since the Early Pleistocene or Late Pliocene, with three major eruptive periods. The current volcanic cone formed during the present eruptive period, which began 150,000 years ago.
Rabaul is a township in the East New Britain province of Papua New Guinea, on the island of New Britain. It lies about 600 kilometres to the east of the island of New Guinea. Rabaul was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash from a volcanic eruption in its harbour. During the eruption, ash was sent thousands of metres into the air, and the subsequent rain of ash caused 80% of the buildings in Rabaul to collapse. After the eruption the capital was moved to Kokopo, about 20 kilometres (12 mi) away. Rabaul is continually threatened by volcanic activity, because it is on the edge of the Rabaul caldera, a flooded caldera of a large pyroclastic shield.
Mount Katmai is a large active stratovolcano on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6.3 miles (10 km) in diameter with a central lake-filled caldera about two by three miles in size, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is located in Kodiak Island Borough, very close to its border with Lake and Peninsula Borough. The volcano has caused ten known fatalities due to gas exposure.
The Volcán de Colima, 3,820 m (12,530 ft), also known as Volcán de Fuego, is part of the Colima Volcanic Complex (CVC) consisting of Volcán de Colima, Nevado de Colima and the eroded El Cántaro. It is the youngest of the three and as of 2015 is one of the most active volcanoes in Mexico and in North America. It has erupted more than 40 times since 1576. One of the largest eruptions was on January 20–24, 1913. Nevado de Colima, also known as Tzapotépetl, lies 5 kilometres (3.1 mi) north of its more active neighbor and is the taller of the two at 4,271 meters. It is the 26th-most prominent peak in North America.
Tavurvur is an active stratovolcano near Rabaul, on the island of New Britain, in Papua New Guinea. It is a sub-vent of the Rabaul caldera and lies on the eastern rim of the larger feature. An eruption of the volcano largely destroyed the nearby town of Rabaul in 1994.
Redoubt Volcano, or Mount Redoubt, is an active stratovolcano in the largely volcanic Aleutian Range of the U.S. state of Alaska. Located at the head of the Chigmit Mountains subrange in Lake Clark National Park and Preserve, the mountain is just west of Cook Inlet, in the Kenai Peninsula Borough about 110 miles (180 km) southwest of Anchorage. At 10,197 feet (3,108 m), in just over 5 miles (8.0 km) Mount Redoubt attains 9,150 feet (2,790 m) of prominence over its surrounding terrain. It is the highest summit in the Aleutian Range. In 1976, Redoubt Volcano was designated as a National Natural Landmark by the National Park Service.
Mount Rinjani is an active volcano in Indonesia on the island of Lombok. Administratively the mountain is in the Regency of North Lombok, West Nusa Tenggara. It rises to 3,726 metres (12,224 ft), making it the second highest volcano in Indonesia. It is also the highest point in the Indonesian province of West Nusa Tenggara.
Mount Okmok is the highest point on the rim of Okmok Caldera on the northeastern part of Umnak Island in the eastern Aleutian Islands of Alaska. This 9.3 kilometers (5.8 mi) wide circular caldera truncates the top of a large shield volcano. The volcano is currently rated by the Alaska Volcano Observatory as Aviation Alert Level Green and Volcanic-alert Level Normal.
Mount Cleveland is a nearly symmetrical stratovolcano on the western end of Chuginadak Island, which is part of the Islands of Four Mountains just west of Umnak Island in the Fox Islands of the Aleutian Islands of Alaska. Mt. Cleveland is 5,675 ft (1,730 m) high, and one of the most active of the 75 or more volcanoes in the larger Aleutian Arc. Aleutian natives named the island after their fire goddess, Chuginadak, who they believed inhabited the volcano. In 1894 a team from the U.S. Coast and Geodetic Survey visited the island and gave Mount Cleveland its current name, after then-president Grover Cleveland.
Cerro Azul, 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.
Reventador is an active stratovolcano which lies in the eastern Andes of Ecuador. It lies in a remote area of the national park of the same name, which is Spanish for "exploder". Since 1541, it has erupted over 25 times, although its isolated location means that many of its eruptions have gone unreported.
Mount Bulusan, also known as Bulusan Volcano, is a stratovolcano on the island of Luzon in the Philippines. Located in the province of Sorsogon in the Bicol Region, it is 70 kilometres (43 mi) southeast of Mayon Volcano and approximately 390 kilometres (240 mi) southeast of the Philippine capital of Manila.
Lake Ilopango is a crater lake which fills an 8 by 11 km volcanic caldera in central El Salvador, on the borders of the San Salvador, La Paz, and Cuscatlán departments. The caldera, which contains the second largest lake in the country and is immediately east of the capital city, San Salvador, has a scalloped 100 m (330 ft) to 500 m (1,600 ft) high rim. Any surplus drains via the Jiboa River to the Pacific Ocean. The local military airbase, Ilopango International Airport, has annual airshows where international pilots from all over the world fly over San Salvador City and Ilopango lake.
Several types of volcanic eruptions—during which lava, tephra, and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series.
Chaitén is a volcanic caldera 3 kilometres (2 mi) in diameter, 17 kilometres (11 mi) west of the elongated ice-capped Michinmahuida volcano and 10 kilometres (6 mi) northeast of the town of Chaitén, near the Gulf of Corcovado in southern Chile. The most recent eruptive phase of the volcano erupted on 2008. Originally, radiocarbon dating of older tephra from the volcano suggested that its last previous eruption was in 7420 BC ± 75 years. However, recent studies have found that the volcano is more active than thought. According to the Global Volcanism Program, its last eruption was in 2011.
Mount Gareloi, or Gareloi Volcano, is a stratovolcano in the Aleutian Islands of Alaska, United States, about 1,259 miles (2,026 km) from Anchorage. Gareloi is located on Gareloi Island, and comprises most of its land mass. The island also has two small glaciers which protrude to the northwest and southeast.
The isolated San Martin Tuxtla volcano is a shield volcano which rises above the Gulf of Mexico. It has had eruptions in historical times. It occurs in the Tuxtla volcanic field in Veracruz, Mexico. Lavas from San Martin vary between basanite and alkali basalt. Locally the volcano is also known as Tiltépetl.
Aso caldera is a geographical feature of Kumamoto Prefecture, Japan. It stretches 25 kilometers north to south and 18 kilometers east to west. The central core "Aso Gogaku" is the five major mountains in the area. Aso valley (Asodani) runs along the northern base of Mount Aso and Nango valley (Nangodani) along the south. According to research of caldera sediment, lakes used to exist in these valleys. The dried up lake areas have come to be called Old Aso Lake, Kugino Lake, and Aso Valley Lake. The Kikuchi, Shirakawa and Kurokawa rivers now drain the caldera.
