composite composite volcano in Guatemala.volcano in Guatemala.

Volcanic island (South sandwich) Volcanic island (South sandwich) composite volcanocomposite volcano

““collapse caldera” collapse caldera” (Poas Volcan, Costa Rica)(Poas Volcan, Costa Rica)

Montserrate with a pyroclastic Montserrate with a pyroclastic cloudcloud

Montserrat volcano, Caribbean and Montserrat volcano, Caribbean and pyroclastic cloudspyroclastic clouds

Crater Lake (caldera)Crater Lake (caldera)Wizard Island (cinder cone)Wizard Island (cinder cone)

Merapi volcano May 14, 2006 Merapi volcano May 14, 2006 IndonesiaIndonesia

Pyroclastic cloud on Mt. Merapi Pyroclastic cloud on Mt. Merapi May 14,2006May 14,2006

A pyroclastic flow of Mt. PinatuboA pyroclastic flow of Mt. Pinatubochasing a truck.chasing a truck.

Lava dome (Mt. Merapi) and lava flow Lava dome (Mt. Merapi) and lava flow 5-14-20065-14-2006

Irazu (composite volcano) Costa RicaIrazu (composite volcano) Costa Rica

Irazu volcano, (composite volcano)Irazu volcano, (composite volcano)alternating lava layers and acidicalternating lava layers and acidic

water in the craterwater in the crater

Cinder coneCinder cone volcano volcano

700 foot Cinder cone volcano 700 foot Cinder cone volcano (northern California)(northern California)

Students climbing a cinder cone volcanoStudents climbing a cinder cone volcano

Mount St.Helens before 1980Mount St.Helens before 1980

North side (Mt. St. Helens) Dec.2005North side (Mt. St. Helens) Dec.2005

Students climbing Mt. St. HelensStudents climbing Mt. St. Helens

summit of Mt. St. Helens summit of Mt. St. Helens (composite volcano)(composite volcano)

Volcanic ash on the summit of Mt. St HelensVolcanic ash on the summit of Mt. St Helens

Mt. St. Helens building domeMt. St. Helens building dome

Lava dome inside the caldera of Lava dome inside the caldera of Mount St. Helen (2004)Mount St. Helen (2004)

Shield volcano in Iceland (1974)Shield volcano in Iceland (1974)

Mt. St. Helens (2006)Mt. St. Helens (2006)

alternating layers of pasty and fluid lavaalternating layers of pasty and fluid lava(Mt. St. Helens)(Mt. St. Helens)

Rising rock mass in the crater of Rising rock mass in the crater of Mt.St. Helens (April 2006)Mt.St. Helens (April 2006)

Crater and active vent of Ertaale Crater and active vent of Ertaale volcano (Ethiopia)volcano (Ethiopia)

““lava coil” in pahoehoe lavalava coil” in pahoehoe lava

pasty ‘aa’ lava flowpasty ‘aa’ lava flow

Lava blister caused by escaping gasesLava blister caused by escaping gases

Yellow sulfur and white acidsYellow sulfur and white acids

Mount PinatuboMount Pinatubo

(Philippines)(Philippines)

ejectsejects

5,000 tons of 5,000 tons of

sulfur dioxidesulfur dioxide

each dayeach day

Lava fountains in the rift of Kilauea Lava fountains in the rift of Kilauea (white lava 1150 degrees C. and the (white lava 1150 degrees C. and the

yellow lava 1090 degrees C.)yellow lava 1090 degrees C.)

volcanic lightningvolcanic lightning

Son of Krakatoa (Son of Krakatoa (cinder cone)cinder cone)east side of the Indian Oceaneast side of the Indian Ocean

TsunamiTsunami similar to the waves similar to the waves produced by Krakatoaproduced by Krakatoa

Mount Etna a composite volcano Mount Etna a composite volcano (Sicily)(Sicily)

Views of Mount Etna’s eruptionViews of Mount Etna’s eruption

Aniakchak Aniakchak explosion caldera explosion caldera (Alaska)(Alaska)

Pahoehoe lava Pahoehoe lava covering a national covering a national park road in Hawaii.park road in Hawaii.

“ “aa” aa” lavalava

pahoehoe pahoehoe lava (Hawaii)lava (Hawaii)

pillow lava (Hawaii)pillow lava (Hawaii)

Mount Mageik (Alaska) Mount Mageik (Alaska) compositecomposite volcanovolcano

LaharLahar produced by the Santiaquito produced by the Santiaquito volcano (Guatemala)volcano (Guatemala)

shield shield volcanovolcano

Pyroclastic debris Pyroclastic debris

Pahoehoe lava (Hawaii)Pahoehoe lava (Hawaii)

Volcanic ashVolcanic ash

Volcanic ventVolcanic vent

fumarole fumarole covered with sulfurcovered with sulfur

House consumed by lava House consumed by lava (Hawaii). (Hawaii).

Portable housePortable house for volcanic regionsfor volcanic regions

Pyroclastic cloud Pyroclastic cloud of ash, cinder and of ash, cinder and burning gases moving at 50 mphburning gases moving at 50 mph

blocks of pumice of a blocks of pumice of a pyroclastic flowpyroclastic flow

Lava surrounds a house (Hawaii)Lava surrounds a house (Hawaii)

Augustine (composite volcano) AlaskaAugustine (composite volcano) Alaska

lava fountain lava fountain and and pyroclastic debrispyroclastic debris from Kilauea volcanofrom Kilauea volcano

Intermediate color of Intermediate color of andesite andesite lava lava