Full glossary

The P wave (short for primary wave, also called pressure or compressional wave) is the seismic wave that shakes the rocks forth and back in the same and opposite direction of the propagation direction (longitudinal).

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Pacaya volcano near Guatemala City is one of Guatemala's most active volcanoes, and its frequent eruptions are often visible from Guatemala City. Typical activity in recent years includes strombolian activity, lava flow emission and intermittend violent phases of lava fountaining.

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Paco volcano (also known as Manlayao or Paco-Manlayao) is located at the NE tip of Mindanao Island, Philippines.
It is an basaltic-dacitic stratovolcano complex truncated by 2 nested calderas, 2.5 and 5 km in diameter. The volcano is located east of the N-S-trending Philippine Fault which cuts through eastern Mindanao.
It has a breached crater with andesitic lava domes. The youngest dated rocks are from a basaltic lava flow between 90,000 and 10,000 years old. Local legends tell about a major caldera collapse eruption.
The age of the last activity is not known, although the volcano currently displays fumarolic activity.
Source: GVP Paco volcano information

Pagan volcano consists of 2 stratovolcanoes (North and South Pagan) connected by a narrow isthmus and forms the largest and one of the most active of the Mariana Islands. It is located 173 nautical miles north of Saipan.
Nearly all historical eruptions of Pagan, which were recorded since the 17th century, were from North Pagan volcano. The largest historic eruption was in 1981 and prompted the evacuation of the sparsely populated island.

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Pago volcano (Witori volcano) is located in the Cape Hoskins area of New Britain, Papua New Guinea. It belongs to the larger complex of Witori volcano and represents the post-caldera cone of the latter.
Pago is probably only 350 years old.
The typical historical activity at Pago volcano were strombolian to vulcanian explosions, sometimes accompanied by slow lava flows. A series of 10 dacitic lava flows from Pago cover much of the caldera floor.

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The older of the two historic volcanic islands in the Santorini caldera.

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Palei-Aike volcano (also written as Pali-Aike volcano) is a young volcanic field along the border of southern Argentina and CHile, north of the Straits of Magellan. It contains lake-filled maars and basaltic cinder cones and young lava flows.

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Palena volcano is a group of 5 cinder cones in southern Chile NE of Melimoyu volcano. The cones are aligned along a NNE trend and are of Holocene age, i.e. younger than 11,700 years. The middle cone is called Cerro Palena and lends its name to the whole group.

Palomo is a small stratovolcano in central Chile, 130 km south of Santiago, and west of the massive Caldera del Atuel. The summit is largely ice-covered. Its young morphology suggests that its last eruptions are relatively recent, perhaps prehispanic, but there has not been any known historic activity.

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Paluweh volcano (also known as Rokatenda), is the tip of a large, mostly submerged stratovolcano rising 3000 m from the sea floor. It forms a small 8 km wide island with the same name north of Flores Island. Paluweh has a complex summit composed of several overlapping craters and lava domes up to 900 m wide.
Several flank vents were formed by flank eruptions on a NW-trending fissure. The largest historical eruption of Paluweh in 1928 was highly explosive and produced a landslide triggering a tsumani.

Pampa Luxsar (also spelled Pampa Luxar) is a volcanic field in SW Bolivia 23 km from the border with Chile. It comprises a 45 x 45 km area of lava flows at the SW margin of Bolivia's Salar de Uyuni east of the Andean volcanic front.

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Pan de Azucar is a probably extinct stratovolcano in a hardly accessible area in the Amazonian jungle between Sumaco and Reventador volcanoes. It has been active around 1 million years ago and produced lava from basaltic to andesitic in composition.

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Mount Panay is small andesitic stratovolcano on the Calumpang Peninsula west of the Batangas Bay, south of Lake Taal, Luzon Island, Philippines.
Panay may be extinct with its last eruptions being more than 10,000 years ago, but it still has strong solfataric activity.

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Paniri is a stratovolcano in northern Chile 26 km SE of San Pedro volcano. It has 3 craters. There are no recent eruptions, but the volcano possibly has been active during the past 10,000 years. Archeological remains have been found on its summit in 1972.
A magnitude 5.4 earthquake occurred at a depth of 106 km under the volcano on 1 Feburay 2008.

The island of Pantelleria is constructed above a drowned continental rift in the Strait of Sicily and has been the locus of intensive volcano-tectonic activity.

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One of West Java's most active volcanoes near Garut.

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Papayo volcano is a small lava dome on the crest of the Sierra Nevada range 47 km SE of Mexico City. Papayo has produced large dacitic lava flows reaching up to 10 km length, and was last active less than 12,000 years ago, meaning it is to be considered potentially active.

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Volcán Parinacota volcano is a symmetrical young stratovolcano in northern Chile near the border with Bolivia. Along with older Pomerape (6222 m) volcano 4 km to the NE it forms the Nevados de Payachata volcanic group.
Parinacota contains a pristine, 300-m-wide summit crater and young lava flows on the western flanks.
There are no historical eruptions, but the volcano has had explosive and effusive eruptions from both the summit crater and the Ajata group of flank vents in the past few 1000 years and is considered an active volcano.

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Parker volcano (also known as Falen locally) is a low, but steep-sided vegetated stratovolcano located 30 km west of General Santos City, near the southern tip of Mindanao Island, Philippines.
The andesitic-dacitic volcano contains a 2.9 km diameter summit caldera with a lake, Lake Maughan (2 km diameter).
Parker was recently identified as the source of a major explosive eruption in 1641, which caused devastating pyroclastic flows and lahars, and heavy ash fall and darkness over Mindanao Island. The 1641 eruption was one of 3 large explosions of Parker volcano within the past 3800 years. It created the present-day summit caldera.
The eruption style of Parker volcano is similar to Pinatubo volcano, which had a Plinian eruption in 1991.

Patah is a heavily forested, dissected Quaternary volcano SE of Dempo volcano.

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Mount Patoc is an andesitic stratovolcano in the Cordillera Central of north-central Luzon, Philippines. It has strong fumarolic activity. A small river and a village on the west side are named "Mainit", which means hot.

Patuha volcano is an old, forest-covered twin volcano with two craters 600 m apart located SW of Bandung city, the capital of West Java. One of its craters is being mined for sulphur.

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Cerro Payún Matru is a massive Hawaiian-style shield volcano in Argentina located lies 530 km from the oceanic trench, which marks the subduction of the Nazca plate. It contains a 8 x 10 km caldera which was formed after about 168,000 years ago.

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Pechan is the youngest cinder cone of the Tianshan volcano in Xinjiang Province in NW China. It was active in the 1st and 7th centuries AD. Pechan is also known by a variety of other names, including Peishan, Baishan, Hochan, Aghie, Bichbalick, Khala, and Boschan.

Peinado volcano is a symmetrical stratovolcano in NW Argentina and one of the youngest volcanoes of the region.
It has young, well preserved lava flows from the summit and flank vents, which extend up to 10 km from the summit.

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Gunung Penanggungan is a small dormant stratovolcano dominating the view from the North coast in the Surabaya area. It is immediately to the north of the higher and more active Arjuno-Welirang twin volcano.
Penanggungan is one of Java's most revered mountains: Ancient Javanese saw in Penanggungan a reflection of the sacred Mahameru of Hindu mythology. There are more than 81 archaeological sites on the mountain, mostly on its northern and western flanks. Ruins of sanctuaries, monuments, and sacred bathing sites of the Hindu period were found, spanning more than 5 centuries from A.D. 977 until 1511.

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Pendan is a little-known volcano in central Sumatra that is listed as an active volcanic center by Rock et al. (1982) and Posavec et al. (1973), with no additional information. Source: Smithsonian GVP

Perbakti volcano is one of a complex of 3 closely located old stratovolcanoes known as the Perbakti-Gagak or Kiaraberes-Gagak volcanic complex situated immediately SW of Salak volcano and near Bogor town.
The 3 volcanoes of the group are, from S to N, Gunung Endut (1474 m), Gunung Perbakti (1699 m), and Gunung Gagak (1511 m).
The complex is hydrothermally very active. Fumaroles, warm spring and boiling mud pools are found on the S and SE sides of the volcano at 950-1300 m elevation. Mild phreatic eruptions took place in historical time from fumarole fields on its flanks.

Peretolchin is a 120 m high young cinder cone in the Oka Plateau of southeastern Russia near Lake Baikal. It produced a voluminous lava flow which is less than 10,000 years old.

Perlite is an amorphous volcanic glass.

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Cerro de Las Petacas volcano is a lava dome in southern Colombia NE of Doña Juana volcano. The age of its last activity is unknown, but there are youthful-looking cinder cones nearby and the volcano might still be considered active.

Peuet Sague is a large volcanic complex that rises to 2801 m in NW Sumatra.

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American-Brasilian volcanologist Philip Ong manages VOLCANO DISCOVERY HAWAI'I.

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Volcanic activity where fresh magma AND external water are involved.

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A prominent 2351-m-high stratovolcano occupying the eastern end of Pico Island is the highest volcano in the Azores.

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Pinacate volcano is a young volcanic field of maars, tuff rings, more than 500 basaltic cinder cones in the Sonoran desert in NW Mexico, a nearly unpopulated region between Arizona and the Gulf of California. The field covers an area of about 60 x 55 km and has been active less than 10,000 years ago.
Papago (Tohono O'odham) Indian legends tell of eruptions in this area, suggesting that activity has been fairly recent. There are accounts of ash-and-steam eruptions in the 20th century, which are believed not to be true by the Smithsonian Global Volcanism Program (GVP).

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Pinatubo volcano exploded spectacularly on 15 June 1991. The Pinatubo eruption on 15 June 1991 was the second largest volcanic eruption of the 20th century.
Pinatubo is a complex of lava domes located 100 km NW of Manila city, Luzon Island, Philippines.
Prior to the eruption, Pinatubo was a little known volcano and it had been dormant for 400 years. There were no known historic eruptions. Before the eruption in 1991 Pinatubo was 1745 m high (ca. 250 m more than now), and was only 200 m higher than the nearby peaks, which are remnants of older volcanic edifices of Mt Pinatubo and hid it from views from distance. Pinatubo mostly noted for a failed geothermal development project.

Eruptions of Mount Pinatubo
Pinatubo has had at least 6 periods of activity with large explosive eruptions in its past 35,000 years prior to the 1991 eruption. The 1991 eruption in this context actually ranks as one of the smaller eruptions. An eruption, which occurred 35,000 years ago and probably created the caldera, was likely much bigger.

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Piton de la Fournaise, a typical basaltic shield volcano, located on the French island La Réunion, is one of the world's most active and productive volcanoes. It is in a phase of frequent but short-lived eruptions that start with lava fountains and produce large lava flows. Since the active areas of the volcano are not inhabited, its eruptions pose little danger and cause little damage.

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Pizzo is the name of the summit ridge above the active craters of Stromboli volcano (Eolian Islands). It is part of the remnants of the collapsed older volcanic edifice of Neostromboli, forming a crest reaching 918 m and about 150 m higher than the present-day active craters. It forms a perfect and very popular viewing point to observe the volcanic activity of Stromboli from close.

Planchón-Peteroa is an elongated complex volcano along the Chile-Argentina border with several overlapping calderas. It is less than 550,000 years old and was formed by 3 different volcanoes representing different generations of the volcano: Azufre, Planchon and Peteroa.
Peteroa has been active into historical time and contains a small steaming crater lake. Historical eruptions from the Planchón-Peteroa complex have been dominantly explosive, although lava flows were erupted in 1837 and 1937.

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The most explosive and largest type of volcanic eruptions. Plinian eruptions erupt more than 1 cubic kilometer of magma often within less than a few days and produce ash columns that can reach 20-50 km height.

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The volcanic Pocdol Mountains (also known as Bacon-Manito complex) are a group of volcanic cones between Saragon Bay and Albay Gulf in southern Luzon.
Some of the cones are probably only a few thousands of years old. A fumarole field and a geyser are found in the area, suggesting it might be still volcanically active.

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Poco Leok volcano is a statovolcano constructed what might be an irregularly shaped 7 km wide caldera in western Flores Island. The highest peaks on the caldera rim are Mt Lus (1675 m), Mt Sesat, Mt Mompong (1383 m), Mt Pitjong, and Mt Mangung (1379 m). It is believed that the Poco Leok and the caldera are still an active, although no historic eruptions are known. 4 active fumarole fields are found inside the caldera between 825 and 1200 m elevation. The Ulumbu geothermal field on the flank of Poco Leok at 650 m elevation includes hot springs, fumaroles, mud ponds and steam vents.
(Source: GVP)