Volcanic Eruptions: a material science

Lecture 2: The Earth as a living planet:

Volcanoes on Earth: magnitudes and landforms

Prof. Dr. Donald Bruce Dingwell Prof. Dr. Cristina P. De Campos (editing and graphics) Dept. of Earth and Environmental Sciences

Yellowstone (2 Ma) Toba (74 ka)

Long Valley (760 ka)

Tambora (1815)

Krakatoa (1883)

Mount Pinatubo (1991) Mount St. Helens (1980)

Magnitudes

redrawn after Miller and Wark 2008

Large igneous provinces (LIPs) on Earth

Columbia River

Caribbean Colombian

Ontang Java

Hikurangi

Manihiki

Magellan

Antartic Plate

Pacific Plate

Shatsky Hess

American

Plate

North Atlantic

Rio Grande

Sierra Leone

Walvis

Conrad

Kerguelen

Madagascar

Eurasian Plate

Deccan

African Plate

Afar

Karoo Indian Plate

Siberian

Nin

etye

ast

Broken

Maud

mod. after Saunders et al. 1992 and Mahoney and Coffin 2009

Volcanic Edifices: different forms at the same scale

Yellowstone Caldera,USA ~ 70 km major axis

Shield volcano Mauna Loa, Hawaii

vent sea level

0 10 km

Composite or stratovolcano Lascar, Chile

Dome, Chaitn, Chile

Cinder Cone, Craters of the Moon,

USA

mod. and redrawn after Winter 2001

after an image of the Lascar Volcano

Andesitic viscous lava flow - (~ 20 m high)

on pyroclastic deposits (ignimbrite) andesite and dacite

Schematic drawing of a stratovolcano

Craters of the Moon, USA. Photo: C. De Campos, 2006.

Cinder Cone

~1.

5 m

Teide Tenerife Island, in the Canary Island archipelago, ca. 80 km long and 54 km at its widest point. Pico de Teide 3,718 m above the sea. August 1991

go to http://earth.jsc.nasa.gov/

Volcanic Eruptions: a material science

Lecture 2: The Earth as a living planet:

Volcanoes on Earth: explosive and effusive volcanism. Videos of Merapi and Etna volcanoes.

ash

fallout

pyroclast from Greek pyros (fire) and klasto (fragment)

Mayon, The Philippines 1984 h#p://volcanoes.usgs.gov

eruption column

velocity up to 600 km/h

pyroclastic flow = ash + gas + rock fragments

Explosive Volcanism: pyroclasts

pyroclastic flow

Volcanic Eruptions: a material science

Lecture 2: The Earth as a living planet:

Volcanic materials

Microscopic photos of a thin section: Croscat scoria cone, Spain

void spaces/ gas bubbles

microcrystalline groundmass

crystal

melt inclusions

photomicrographs: C. Cimarelli

2 mm

2 mm

glass

melt inclusions in

a pyroxene crystal

photomicrograph: C. De Campos

~ 0.2 mm

from Campi Flegrei, Naples, Italy

Magma is multiphase: u liquid (may be mingled, mixed) u crystals u bubbles

volcanic ash, Fuego

3 crystalline phases

from C. Cimarelli

Volcanic Eruptions: a material science

Lecture 2: The Earth as a living planet:

Volcanic materials: mineralogy and fragment classification

Olivine

Pyroxene

Amphibole

Biotite

Muscovite Quartz

Ca-Plagioclase

Na-Plagioclase

Orthoclase

high T

low T

Volcanoes: Mineralogy

1 m 5 m

Complexly zoned plagioclase crystal (phenocryst) from an

andesite (Poros, Greece). Photomicrographs under

cross-polarized light.

photomicrographs: C. De Campos

Classification of Pyroclasts: type of fragment

redrawn aBer PeDtjohn 1975

Lapilli

Choose your own image

Bomb

Ash Tephra:

Ash < 2 mm Lapilli 2 64 mm Bomb > 64 mm

http://www.vulkane.net/

http://www.vulkane.net/

Krakatoa 2010

Krakatoa 2010

Volcanic Eruptions: a material science

Lecture 2: The Earth as a living planet:

Volcanic materials: chemical and mineralogical classification

Chemical

Classification

77736965

63

5753

52

4945

45

4137

1

3

5

7

9

11

13

15

61

SiO wt%2ultrabasic basic intermediate acid

Na O+K 0 wt%2 2

basanite(ol>10%)

phono-tephrite

tephri-phonolite

phonolite

rhyolite

daciteandesitebasaltic

andesite

basaltictrachy- andesitetrachy-

basalt

basaltpicro-basalt

trachy-andesite

trachyteq20%

tephrite(ol

Mineralogical Classification of

Volcanic Products

The Q(quartz)-A(alkali-feldspar)- P(plagioclase) -

Diagram

simplified after Le Matre 1989

Le Maitre RW (ed) 1989 A Classification of Igneous Rocks and Glossary of ....Blackwell, Australia. Mahoney JJ, Coffin MF (eds) 2009 Large Igneous Provinces: ...IUGG Geophysical Mon. 100 AGU. Miller CF, Wark DA 2008 Supervolcanos ... ELEMENTS 4: 11-16. Petitjohn FJ 1975 Sedimentary Rocks, 3rd edition, New York: Harper and Row. Saunders AD, Storey M, Kent RW, Norry MJ 1992 Consequences of plume-lithosphere interactions. In: Storey

BC, Alabaster T, Pankhurst RL (eds) Magmatism and the Causes of Continental Break-up. Geol. Soc. London, Special Publ. 68:41:60.

Schmincke H-U 1998 Volcanism, Springer. Winter JD 2001 An Introduction to Igneous and Metamorphic Petrology. Prentice Hall. NASA http://earth.jsc.nasa.gov/ http://www.volcano.si.edu/education/ USGS http://volcanoes.usgs.gov/ http://www.nps.gov/crmo/naturescience/ Smithsonian Institute: Global Volcanism Program http://www.volcano.si.edu/world/find_regions.cfm www.vulkane.net

Source of illustrations and references:

http://commons.wikimedia.org/wiki/