1 Volcanoes and Volcanism GLY 2010 – Summer 2015 – Lecture 8 Eruption of Mt. Vesuvius, Italy

2 Volcano A vent in the surface of the Earth through which magma and associated gases and ash erupt Also, the form or structure, usually conical, that is produced by the ejected material Plural: volcanoes Etymology: the Roman deity of fire, Vulcan

3 Pyroclastic Eruptions Magma spews upward with great force through a central vent Left: Mt. St. Helens, 1980 Right: Kilauea, Hawaii

Fissure Eruptions Video 4  Iceland's Bardarbunga volcano system

5 Fissure Image Eruptive fissure on southeast rim of Kilauea caldera, Hawaii

6 Fissure Eruption Mauna Loa Volcano, Hawaii

Lava Flow Video Kilauea, Hawaii, July 13,

Flowing Lava Video 8

9 Columbia River Flood Basalt Imnahu River Canyon Photo: Stephen Reidel

10 Columbia River Flood Basalt Grande Ronde Basalt

11 Pillow Basalt

Pillow Flow, Hawaii 12

13 Pillow Deltas

Undersea Volcano Eruptions 14

Birth of an Island 15

16 Vesicles

17 Scoria

18 Lava Tube or Tunnel

19 Nahuku Lava Tube Thurston (Nahuku) lava tube Near summit caldera of Kilauea Volcano, Hawaii Volcanoes National Park

20 Lava Tube, Hawaii

21 Lava-Sicles Ape Cave, Mt. St. Helens

22 Andesite Volcanoes Nevado Ojos del Salado, Chile /Argentina frontier

23 Andesite Lava Flow and Dome Volcan Láscar (Chile)

24 Rhyolitic Lava San Francisco Peaks stratovolcano, Arizona Sugarloaf Mountain, the small dome-shaped hill in the foreground, is a rhyolite dome

25 Tephra General term for fragments of volcanic rock and lava that, regardless of size, are blasted into the air by explosions or carried upward by hot gases in eruption columns or lava fountains

26 Tephra Eruption The Puu Oo cone, the main vent for Kilauea from , is made of cinder and spatter from numerous lava fountains Photograph by J.D. Griggs, U.S. Geological Survey

27 Volcanic Ash Fall Mount Pinatubo (Philippines )

28 Effect on Climate Large volcanic eruptions can block a great deal of the sun’s energy from reaching the earth’s surface This cools the climate until the tephra particles sink to the surface

29 Krakatau Volcano Located in the Sunda strait between the islands of Java and Sumatra

30 Krakatau, 1883 Eruption Sunset, Chelsea, London, 11/26/1883 William Ascroft

31 Tephra Effects Rabaul Town and Harbor after eruption Rabaul Town and Harbor before eruption

32 Tephra Effects The village of Galunggung, Indonesia, buried in volcanic ash

33 Tephra Effects Trees covered with volcanic ash near Mount St. Helens, Washington

34 Nuée Ardente A swiftly flowing, turbulent gaseous cloud, sometimes incandescent, erupted from a volcano and containing ash and other pyroclastics in its lower part; a density current of pyroclastic flow Etymology: French, "glowing cloud"

35 Mt. Pelée, Martinique

36 Location of Mt. Pelée

37 Eruption of Mt. Pelée

38 Mt. Pelée Nuée Ardente Photograph of a pyroclastic flow by Heilprin, 1902

39 St. Pierre After Eruption Photograph of the remains of St. Pierre by Heilprin, 1902

40 Later Eruption Ash cloud above Mt. Pelée Photograph of Mt. Pelée by Heilprin, August 30, 1902

41 Mt. Pelée Now

42 Stratovolcano A volcano that is constructed of alternating layers of lava and pyroclastic deposits, along with abundant dikes and sills Synonym: composite volcano; composite cone

43 Mt. Fuji, Japan

44 Arenal Volcano, Costa Rica

45 Movies of the eruption of Mt. Ruapehu, New Zealand, 1995

46 Crater Lake, Oregon Crater Lake, despite the name, is a caldera, formed after the eruption of ancient Mt. Mazama about 6600 y.b.p.

47 Cinder Cone Wizard Island, within Crater Lake, is a cinder cone, and one of the tallest in the world

48 Effusive Eruptions Shield Central vent Fissure Submarine

49 Shield Volcano A volcano in the shape of a flattened dome, broad and low, built by flows of very fluid basaltic lava or by rhyolitic ash flows Shield volcanoes are the largest volcanoes on Earth that actually look like volcanoes (i.e. not counting flood basalt flows)

50 Hawaiian Shield Volcanoes These are the largest volcanoes on Earth

51 Mauna Loa

52 Volcanic Vent Image Small lava fountain erupts from a new vent on the flank of Pu`u `O`o spatter and cinder cone on the east rift zone of Kilauea Volcano, Hawaii

53 Vent and Steam Explosion Mt. St. Helens

Viscosity and Lava Video The viscosity of lava affects lava properties 54

A’a block flow, Kilauea, Hawaii 55

56 Kilauea Lava Entering Water Videos By Steve O'Meara of Volcano Watch International Hot lava shooting out of lava flow wall, like water from a firehose, from Volcanovideo

Pahoehoe Flow Video 57

Fire Fountains, Kilauea Video Kilauea eruption, February 9-10,

Eyjafjallajökull 59 Increase in seismic activity from late 2009 through March 20, 2010, when initial eruption occurred A new eruption starting April 14, 2010 created an ash cloud which approached European air space, causing widespread closure of European airports and massive travel disruptions Eruption released 250,000,000 m 3 of volcanic ash, to a height of 9000 m (30,000 feet) Fine ash created by lava and ice (in the caldera) reaction

Eyjafjallajökull Ash Cloud 60 Composite map of the volcanic ash cloud spanning 14–25 April 2010 Many airports shut from April 15 to April 20 By some accounts, the largest disruption of European air travel since WWII

61 Age of Submarine Lava Contact between young pillow lavas erupted in mid- 1980s and older lavas with light dusting of sediment

62 Volcanology As a Profession - Videos (Upper) Cindy from Volcanovideo taping a flow More than a dozen internationally known volcanologists were killed during the 1990’s (Lower) Volcanologists collecting samples from erupting volcano (with sound)

63 Oceanic Volcanoes

64 Areal Distribution of Volcanoes

65 Prediction of Volcanic Eruptions Man cannot stop subduction, or magma generation - therefore, the prediction of imminent eruption becomes very important