Full glossary

Gagak belongs to the Perbakti-Gagak or Kiaraberes-Gagak volcanic complex near Bogor, immediately SW of Salak volcano.
The 3 volcanoes of the group are, from S to N, Gunung Endut (1474 m), Gunung Perbakti (1699 m), and Gunung Gagak (1511 m).
Gunung Gagak lies to the NW of the group and is known for its large pumice and obsidian deposit at the summit, and obsidian lava flows extending to the north and NE.

Galeras is one of Colombia's most active volcanoes. In an eruption in 1993, it killed a group of scientists and tourists who had been inside its crater when it erupted.

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Gallego volcano is a group of eroded cones covering a large part of the NW end of Guadalcanal Island. Mount Esperance, a small but well-preserved andesitic cone is said by to have been active less than 2000 years ago, according to local traditions. It is possible, however that these refer to eruptions of the younger Savo volcano.

Galunggung volcano about 100 km SE of West Java's capital Bandung had its last major eruption in 1982, when ash plumes reached 20 km.

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Gamalama (Peak of Ternate) is a near-perfect conical stratovolcano that forms the entire island of Ternate off the western coast of Halmahera. It is one of Indonesia's most active volcanoes.

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Garbuna volcano (officially named Krummel-Garbuna-Welcker volcano) lies at the southern end of the Willaumez Peninsula, New Britain. It is part of a basaltic-to-dacitic volcano group consisting of 3 volcanic peaks, Krummel, Garbuna, and Welcker.
Garbuna volcano erupted on 17 October 2005 after having been dormant for almost 1800 years.

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Mt Garibaldi volcano at the head of Howe Sound, 66 km north of Vancouver in SW British Columbia is probably Canada's best-known volcano and part of the active Cascades Range. It is a young stratovolcano capped by a complex of lava domes. Its most recent eruptions occurred at the Opal Cone on the SE flank ca. 8000 years ago and produced the Ring Creek lava flow.

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Garibaldi Lake is a group of 9 small small andesitic stratovolcanoes and basaltic-andesite cones located 70 km north of Vancouverin SW British Columbia, Canada. The most recent eruptions occurred from Clinker Peak probably around 10,000 years ago.

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Garove volcano forms the 12 km long and low Garove Island, the largest of the Witu Island group located 40 miles (65 km) north of New Britain Island in the Bismarck Sea.
Garove volcano has a 5 km wide flooded caldera open to the sea through a narrow breach on the southern side, where it forms Johann Albrecht harbour.
The island has fumarole fields and thermal areas.

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Garua (Talasea) volcano (or Garua Harbour volcano) is a volcanic field on the Willaumez Peninsula in New Britain, Papua New Guinea.
It has abundant geothermal activity with hot springs, large boiling pools, fumaroles, and small geysers, in particular along the shores of Garua Harbour and on the north shore near Pangalu village. Mudpots occur near Talasea on the south shore.

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Gaua is one of the most remote and most active volcanoes of the Vanuatu archipel, located on the island with the same name in the West Banks island group atht enorthern end of the archipelago. Its most recent eruption started in Sep 2009 from Mt Garet inside the caldera lake and is ongoing (as of April 2010).

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Geology is the science and study of the solid matter that constitutes the Earth.

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The Ghegam Ridge, located in west-central Armenia between the capital city of Yerevan and Lake Sevan, contains a broad concentration of lava domes and pyroclastic cones of Pleistocene-to-Holocene age.

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Gilbanta (also spelled Gilibanta) is a submarine volcano off the western coast of Komodo Island. There are vague reports suggesting activity in 1957.

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Mt Giluwe is the highest volcano in Pacific Oceania and considered one of "the 7 volcanic summits" (not Mauna Kea on Hawaii, as many think: Giluwe is 162 m higher).
It is an ancient extinct shield volcano with 2 prominent 400 m high cones forming its summit, called the main peak and the slightly lower eastern peak (4300 m).
Occasionally, the summit receives snow fall.

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A huge volcano north of Van lake with a great eruption crater towards south-east.

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Glacier Peak is a stratovolcano in northern Washington and the most remote of the Cascade volcanoes. Its name comes from the 11 glaciers on its flanks.
Although it reaches more than 10,000 feet elevation, the volcanic edifice is only 500-1000 m high, because the volcano's base is located on a high ridge.

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Goat Rocks is the center a deeply eroded, glaciated volcanic center of a volcanic field 30 km (18 miles) north of Mount Adams, Washnington, USA.

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The Golden Trout Creek volcanic field consists of a group of cinder cones and lava flows in the Toowa Toowa valley of the Sierra Nevada, California, about 25 km south of Mount Whitney.
Toowa valley is a broad and open valley about 8600 feet high, dotted with cones rising 100-200 m above the valley floor. 4 volcanic centers have been identified at the Golden Trout Creek volcanic field.

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Golets and Tornyi are 2 pyroclastic cones located SW of Medvezhii on Iturup Island, Kurile Islands, Russia. They occupy one of the narrowest parts of the island.
The age of their last eruptions is unknown, but probably about 10,000 years ago. A lava flow from the andesitic-dacitic Tornyi cone (417 m) is seen inside a glacial depression.
Golets cone itself was constructed above the eroded remnants of the extinct Parusnaya Mountain volcano. Lava flows from Golets reached the coast.
(Source: GVP / Smithsonian volcano information)

Göllü Dağ, a 2143-m-high rhyolitic-to-rhyodacitic lava dome complex in central Anatolia, lies between the Hasan Dağ and Acigöl-Nevsehir volcanic complexes.

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Golovnin volcano (or Tomariyama in Japanese) is the southernmost volcano in the Kurile Islands and forms the southern end of Kunashir Island, located only 33 km across the Nemuro Strait from Hokkaido Island in Japan.
It has a 4x5 km wide caldera with an 1x2.5 km wide lake, active solfataric areas at the northern lake shore and several explosion craters, one of which contains a hot crater lake with reported temperatures ranging between 36-100 degrees C. The lake drains through a narrow gap in the western caldera wall. It is part of a protected reserve and swimming in the lake is prohibited.
The only known historical eruption of Golovnin volcano consisted in a minor explosion in 1848.

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Goodenough (Nidula) Island is a roughly circular volcanic island with 26 km diameter and the westernmost of the D'Entrecasteaux Islands off the NE end of New Guinea. Goodenough volcano contains several young basaltic-andesite and andesitic eruptive centers which may only be a few hundred years old.
At present, there are thermal areas and hot springs in several areas, including 1.5 km north-west of Nou Nou, south-west of Wakala Hill, on the coast east of Bolu Bolu, and 3 km north of Bolu Bolu.
Goodenough Island with its very steep cliffs might be one of the steepest islands in the world.

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Gorely volcano is one of the most active volcanoes in southern Kamchatka and located 75 km SW of Petropavlovsk. It is a complex of several overlapping stratovolcanoes with many summit and flank craters. Activity in historic times were mainly small to medium-sized ash and steam eruptions.

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Goriaschaia Sopka (also spelled Goriaschaya Sopka) is a frequently active volcano on SW Simushir Island, Kurile Islands.
Its active vent is an andesitic lava dome volcano within a large horseshoe-shaped crater cutting the NW flank of what is left of the older Igla Mountain volcano (a somma). Igla Mountain is very close to Milne volcano.
The Sopka dome is probably only about 150 years old. It has erupted many young lava flows with prominent marginal levees. Some of them reached the sea where they created an irregular shoreline.
Observed historical activity were mainly mild to moderate ash explosions and strombolian.

The SE end of Graciosa, the northernmost of the central Azorean islands, contains a small 0.9 x 1.6 km caldera with active fumaroles.

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The largely Miocene-to-Pliocene island of Gran Canaria in the middle of the Canary archipelago has been strongly eroded into steep-walled radial gorges called barrancos.

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Gran Cratere is the main crater of Vulcano volcano (Eolian Islands, Italy).

Granada volcano is a system of N-S trending fissure vents, cinder cones and craters located in western Nicaragua between the city of Granada (the oldest city founded by Europeans on the American continent) on the northwestern shore of Lake Nicaragua and the northern flanks of Mombacho volcano.
The earliest eruptions were dated to about 12,000 years ago and the latest activity could be as recent as 2000 years.
A prominent feature is the La Joya explosions craters SW of Granada town. Current activity is limited to hot springs and areas of hot ground at the western shore of Laguna Apoyo, but future eruptions are possible and pose a significant hazard to Granada town.

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Granite is the most well-known and one of the most common intrusive magmatic (plutonic) rock type. It is formed when an intrusion of viscous magma with high silica content (68-75 wt %) remains under the surface of the earth, where it cools and crystallizes slowly inside the crust.

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Literally, the "Ice Cave" - the Grotta del Gelo is the most famous and one of the most remote lava caves on Etna volcano. It is permanently filled with a small glacier - the southernmost glacier in Europe!

Grozny volcano (Etorofu Yake-yama in Japanese) in central Iturup Island, Kuriles, is one of the most frequently active volcanoes of the volcanic island chain.
It is a complex of 2 volcanoes: Ivan Grozny volcano and Tebenkov (also known as Odamoi-san) volcano.
Ivan Grozny volcano has a 3-3.5 km diameter caldera open to the south and includes the andesitic Grozny lava dome, whose name is also used for the whole complex. All known historic eruptions took place from Ivan Grozny volcano.

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Guadalupe volcano is a mostly submerged volcano that forms the island of the same name 250 km west off the coast of Baja California. The volcano was built on the old axis of an ancient spreading center and consists of 2 overlapping shields, the southern of which is the older.
The younger northern volcano could still be active and has probably erupted during the Holocene.

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Guagua Pichincha is one of Ecuador's most active volcanoes. The stratovolcano is part of a complex that rises immediately west of the capital Quito, at only 8 km distance from the city center. 3 major explosive eruptions have occurred at Guagua Pichincha in the past 2000 years, the most recent one in 1660. An event of similar size today is a major threat to the ca. 2 million city of Quito.
The volcano and the older extinct Rucu Pichincha stratovolcano form a broad volcanic massif 23 km in diameter. Historical activity of the volcano has included large explosive eruptions some of which produced sub-plinian and plinian eruption columns, lava domes. Guagua Pichincha volcano's eruptions frequently produce dangerous pyroclastic flows.
Following a 100 year long interval of being dormant, Guagua Pichincha volcano has entered a new phase of low seismic, phreatic and magmatic activity in 1981.

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Volcán Guallatiri in northern Chile just west of the Bolivian border is one of northern Chile's most active volcanoes.
It is a symmetrical ice-covered stratovolcano at the SW end of the Nevados de Quimsachata volcano group. Its summit contains a dacitic lava dome complex with the active vent located at its southern side.
There are thick lava flows on the lower northern and western flanks of the andesitic-to-rhyolitic volcano.
In historic times, Guallatiri's activity consisted in small explosive ash eruptions. There is intense fumarolic activity with "jet-like" noises, and numerous solfataras are located more than 300 m down the west flank.

Source: Smithsonian / GVP Guallatiri volcano information

Guayaques volcano is a group of lava domes in northern Chile on the border with Bolivia. The group of domes forms a 10 km long N-S trending chain and has fed thick, viscous lava flows extending up to about 3 km from the vents.
The youngest domes appear to be north of the summit crater of the dome complex and are less than 10,000 years old.

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Guazapa volcano an eroded basaltic stratovolcano 23 km NE of San Salvador city. It is not known whether the Pleistocene volcano is still active. It shows signs of intense erosion that have cut deep valleys into its flanks, suggestin a very long dormany period, and there is no crater morphology left.
However, Cerro Macanze is a scoria cone at the SE base of the volcano, which is considered by some to be only a few thousands of years old.

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Gunung Api Wetar (Gunung Api = Fire Mountain) volcano forms a small round island in an isolated location in the Banda Sea, Indonesia. The volcano is a massive stratovolcano, rising 5 km from the sea floor; the island is just the uppermost 282 m above water. It is built from lava flows and has a central crater with an intra-crater cone. The slopes of Gunung Api show evidence of 3 large landslides, the largest of which forms en embayment on the NE coast.
The youngest lava flow descended the SW flank to the coast. Explosive eruptions in 1512 and 1699 are the only known historical activity of Gunung Api Wetar.

Ranau is an 8 x 13 km caldera volcano in southern Sumatra partially filled by the crescent-shaped Lake Ranau. Gunung Semuning is a potentially still active stratovolcano constructed at the SE side of the caldera.

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