mt. tambora " the largest volcanic eruption in recorded history "

Geographical setting and Geological history

Sumbawa Island

Sumbawa Island is composed of Early Miocene volcanics, Middle Miocene (20-15 Ma) reef limestones and sandstones (Takada et al., 2000), Pliocenevolcanoes (5-3 Ma), Early Pleistocene volcanoes (1.7-1.1 Ma) and coral reefli t d Middl Pl i t t H l l (B b i t llimestones, and Middle Pleistocene to Holocene volcanoes (Barberi et al.,1983). Tambora volcano, which is younger than 200 ka, overlies coral reeflimestone on its western foot, and cover an older volcano, here called KawindaToi volcano (410 ka) on the northern foot (Takada et al., 2000).

Lesser Sunda Islands

The Global Volcanism Program database for Lesser Sunda Islands currently contains 29 Holocene volcanoes,sorted below in geographical (volcano number) ordersorted below in geographical (volcano number) order

Lesser Sunda Islands are located on the eastern sector of the Sunda arc. More than 100 Quaternary volcanoes have developed along the Sunda arc.

IndonesiaIndonesia

The Global Volcanism Program database for Volcanoes of Indonesia currently contains 146 Holocene volcanoes and 4 Pleistocene volcanoes with thermal activity

These are caused by the northward subduction of the Australian plate beneath the Eurasian plate (Hamilton, 1979). Just to the east, however, thetectonics is complicated by a change in the nature of the subducting plate from oceanic to continental. The thickness of the crust from Java to Baliislands is estimated to be about 20 km (Silver et al., 1983).

Benioff zone beneath Tambora, SumbawaSumbawa

Tambora lies 340 km north of the Java Trench system and 180–190 kmyabove the upper surface of the active north-dipping subduction zone.

o Circles show location of earthquakes below Tambora

Mantle tomographySumbawa subduction zone

Red : slow seismic velocityBlue: fast seismic velocity

Subduction slab beneathTambora to ˃ 1000 km

Sigurdsson H. “Lost kingdom of Tambora”. Graduate School of Oceanography, University of Rhode Island

Eruptive History(Mt. Tambora)

Start Date: 1967 ± 20 years Stop Date: Unknown

Dating Technique: Historical

Start Date: 1812 Stop Date: 1815 Jul 15 (?)

Eruptive Characteristics:Dating Technique: Historical Records

Volcanic Explosivity Index (VEI): 0

Eruptive Characteristics: Central vent eruption Lava flow(s)

Dating Technique: Historical Records


Eruptive Characteristics: Central vent eruption Explosive eruption Pyroclastic flow(s) Fatalities D (l d t

Area of Activity: NE part of caldera floor

Lava flow(s)

Start Date: 1880 ± 30 years Stop Date: Unknown

p y ( )

Tephra Volume: 1.6 x 1011 m3

Damage (land, property, etc.) Tsunami (giant sea waves) Caldera collapse Evacuation


Volcanic Explosivity Index

Eruptive Characteristics: Central vent eruption Explosive eruption

Start Date: 740 AD ± 150 years Stop Date: Unknown

DatingTechnique: Radiocarbon (uncorrected)

Eruptive Characteristics: Central vent eruptionExplosive eruptionVolcanic Explosivity Index

(VEI): 2

Area of Activity: SW part of caldera (Doro Afi Toi)

Explosive eruption Lava flow(s) Lava dome extrusion

Explosive eruption

Start Date: 3050 BC (?) Stop Date: Unknown

Dating Technique: Radiocarbon (uncorrected)

Eruptive Characteristics: Central vent eruption Explosive eruption

Start Date: 1819 Aug Stop Date: Unknown


Eruptive Characteristics: Central vent eruption

(uncorrected) Explosive eruption Pyroclastic flow(s)

Start Date: 3910 BC ± 200 years Stop Date: Unknown

Eruptive Characteristics:


Central vent eruptionExplosive eruption

Dating Technique: Radiocarbon (uncorrected)

Central vent eruption Explosive eruption Pyroclastic flow(s)

The 1815 eruption of the Tambora volcano is generally considered as the largest and most violent volcanicevent in recorded history. An estimated 150 km3 of volcanic material was released (the approximate equivalentevent in recorded history. An estimated 150 km of volcanic material was released (the approximate equivalentto 16,000 Hiroshima bombs or eight times greater than the 1883 Krakatau eruption). The magnitude was sevenon the VEI scale. It was an explosive central vent eruption with pyroclastic flows and a caldera collapse,causing tsunamis, and extensive land and property damage. It had a long-term effect on global climate.

Eruption size distribution

2500 km3Yellowstone

2.2 My BP

Yellowstone630 000 y BP 1000 km

3

630,000 y BP

Yellowstone1 3 my BP

1000 km

1.3 my BP

3

Tambora 1815Mount Mazama 7 600 y BPPinatubo 1991

280 km

Mount Mazama 7,600 y BPKrakatau 1883

Pinatubo 1991Mount St Helens 1980

The 35 x 100 km wide Toba caldera partially filled by waters of Sumatra's Lake Toba is

Toba

The 35 x 100 km wide Toba caldera, partially filled by waters of Sumatra s Lake Toba, isEarth's largest Quaternary caldera. This view looks west toward the northern end ofSamosir Island, which is part of a massive inclined block uplifted after eruption of theYoung Toba Tuff (YTT) about 74,000 years ago. The island, once entirely covered byLake Toba, is formed of caldera-fill deposits of YTT capped by lake sediments.

106

108

101 0

101 2

Tephra volume (m )3

100,000

10 000

Eruptions per thousands of years

10,000

1,000

Nevado del Ruiz 1985

G l 1982

100

erup

tions

Galunggung 1982

Mount St. Helens1980

10

Num

ber

of

Krakatau1883

1

N

Tambora 1815

0.1Yellowstone2 my BP

0.01

2 3 5 6 7 8

Volcanic Explosivity Index (VEI)

Comparison of selected volcanic eruptionsvolcanic eruptions

Eruptions Year Columnheight (km) VEI N. hemisphere

summer anomaly (°C) Fatalities

Mount Vesuvius 79 A.D. align="center" | 30 6 ? unlikely

Taupo 181 51 7 ? unlikelyBaekdu 969 25 6–7 ? ?Kuwae 1452 ? 6 −0.5 ?

Huaynaputina 1600 46 6 −0.8 ≈1400Tambora 1815 43 7 −0.5 > 71,000Krakatau 1883 25 6 −0.3 36,600

Santamaría 1902 34 6 no anomaly 7,000–13,000Katmai 1912 32 6 −0.4 2

Mt. St. Helens 1980 19 5 no anomaly 57

El Chichón 1982 32 4–5 ? > 2,000

Nevado del Ruiz 1985 27 3 no anomaly 23 000Nevado del Ruiz 1985 27 3 no anomaly 23,000Pinatubo 1991 34 6 −0.5 1202

Source: Oppenheimer (2003), and Smithsonian Global Volcanism Program for VEI.

Deadliest Historic Volcanic EruptionsN D th V l Wh M j C f D thNo. Deaths Volcano When Major Cause of Death1. 92,000 Tambora, Indonesia 1815 Starvation2. 36,417 Krakatau, Indonesia 1883 Tsunami3. 29,025 Mt. Pelee, Martinique 1902 Ash flows4. 25,000 Ruiz, Colombia 1985 Mudflows5. 14,300 Unzen, Japan 1792 Volcano collapse, tsunami6. 9,350 Laki, Iceland 1783 Starvation7. 5 110 Kelut Indonesia 1919 Mudflows7. 5,110 Kelut, Indonesia 1919 Mudflows8. 4,011 Galunggung, Indonesia 1982 Mudflows9. 3,500 Vesuvius, Italy 1631 Mudflows, lava flows10. 3,360 Vesuvius, Italy 79 Ash flows and falls 11 2 957 P d I d i 1772 A h fl11. 2,957 Papandayan, Indonesia 1772 Ash flows12. 2,942 Lamington, Papua N.G. 1951 Ash flows13. 2,000 El Chichon, Mexico 1982 Ash flows14. 1,680 Soufriere, St Vincent 1902 Ash flows 15. 1,475 Oshima, Japan 1741 Tsunami16. 1,377 Asama, Japan 1783 Ash flows, mudflows17. 1,335 Taal, Philippines 1911 Ash flows18. 1 200 Mayon Philippines 1814 Mudflows18. 1,200 Mayon, Philippines 1814 Mudflows19. 1,184 Agung, Indonesia 1963 Ash flows20. 1,000 Cotopaxi, Ecuador 1877 Mudflows21. 800 Pinatubo, Philippines 1991 Roof collapses and disease2222. 700 Komagatake, Japan 1640 Tsunami23. 700 Ruiz, Colombia 1845 Mudflows24. 500 Hibok-Hibok, Philippines 1951 Ash flows

Dr. Oleg Melnik . “Physical Volcanology Course; Lecture 1Institute of Mechanics, Moscow State University

Historical volcanic tsunamiHistorical volcanic tsunami

Volcano Year Cause Death toll NotesVolcano Year Cause Death toll Notes

Komaga-Take (Japan) 1640 landslide 700

Santorini (Greece) 1650 eruption 50

Long Island (Papua New Guines) 1660 eruption ~2000 Tsunami and pyroclastic flows

Gamkonora (Indonesia) 1673 eruption many

Oshima-Oshima (Japan) 1741 landslide 1475

Unzen (Japan) 1792 landslide 14,528

Tambora (Indonesia) 1815 eruption many 10,000 killed by direct effects of eruption

Ruang (Indonesia) 1871 landslide 400 Collapse of lava domeRuang (Indonesia) 1871 landslide 400 Collapse of lava dome

Krakatoa (Indonesia) 1883 eruption 36,417 Most killed by tsunami

Ritter Island (Papua New Guinea) 1888 landslide ~3000 Waves 12-15m high

Taal (Philippines) 1965 eruption >200 Most drowned due to boats capsizing

Iliwerung (Indonesia) 1979 landslide 539 Waves 9m high

GEOL 3026 Geological Hazards2006

Chronology of the largest eruptionChronology of the largest eruption(Mt. (Mt. Tambora)Tambora)

• In 1812, the caldera began to rumble and generated a dark cloud.• On 5 April 1815, a moderate-sized eruption occurred, followed by thunderous detonation sounds, heard in Makassar (380 km),

Batavia/Jakarta (1,260 km), and Ternate (1400 km).• On the morning of 6 April 1815, volcanic ash began to fall in East Java with faint detonation sounds lasting until 10 April 1815.• What was first thought to be sound of firing guns was heard on 10–11 April on Sumatra island (more than 2,600 km).

Tambora caldera

Mt. Tambora

• At about 7 p.m. on 10 April, the eruptions intensified. Three columns of flame rose up and merged. The whole mountainwas turned into a flowing mass of "liquid fire”. Pumice stones of up to 20 cm in diameter started to rain down at

i t l 8 f ll d b h t d 9 10 H t l ti fl d d d th t i t thapproximately 8 p.m., followed by ash at around 9–10 p.m. Hot pyroclastic flows cascaded down the mountain to the seaon all sides of the peninsula, wiping out the village of Tambora.

• Loud explosions were heard until the next evening, 11 April 1815. The ash veil had spread as far as West Java and SouthSulawesi.

The foot of Tambora volcano

T i f l ti l d t h i ht t k th h f th I d i i l d 10 A il 1815 Th t• Tsunami of relatively modest height struck the shores of the Indonesian islands on 10 April 1815. The wave rose to amaximum height of 4 m at Sanggar for a short time around 10 pm, and reached Besuki in East Java (500 km away) with aheight of 1 to 2 m, before midnight. Travel time for a wave between Tambora and Besuki was estimated to be about 2 hours;therefore its average velocity must have been of 70 m/sec.Th t i l b d i M l k i l d ith h i ht f 2 Th h i l f th t i• The tsunami was also observed in Maluku islands with a wave height of over 2 m. The physical cause of the tsunami wasprobably the sudden entry of the pyroclastic flows into the sea that was reported to have taken place in the three coastaltowns; Tambora, Sanggar, and Bima.

• Another tsunami reached Sumenep on Madura at 7 pm on 11 April 1815 with a height of about 1 m.

Stratigraphy of 1815 deposit

Pyroclastic flow 10 – 13 April 1815

Pyroclastic surge 10 pm (10 April 1815)

Pumice fall 7-10 pm (10 April 1815)

Ash fall 5 – 10 April 1815

Pumice fall 5 April 1815Ash fall 1813 – 1815Pre-eruption soil


TamboraTambora volcano with shieldvolcano with shield--shape which was reconstructed of about 4,shape which was reconstructed of about 4,3300 before 1815. Two parasitic00 before 1815. Two parasitic cones are in foreground.cones are in foreground.There are at least 20 parasiticparasitic cones.cones. Some of them have names: Tahe (877 m), Molo (602 m), Kadiendinae, Kubah (1648 m) and Doro Api Toi.

Most of these parasitic cones have produced basaltic lavas.

Original height: ~ 4300 mg g

Present height : ~ 2850 mg

Caldera FormationCaldera Formation6 6 -- 7 km Diameter7 km Diameter1 1 –– 1.3 km deep1.3 km deep

Tambora caldera

Mt. Mayon, Philippines Mt. St. Helens, USA

•• TheThe eruptioneruption columncolumn duringduring thethe 18151815 eruptioneruption ofof thethe Tambora volcano reachedreached thethe stratospherestratosphere anan•• TheThe eruptioneruption columncolumn duringduring thethe 18151815 eruptioneruption ofof thethe Tambora volcano reachedreached thethe stratospherestratosphere,, ananaltitudealtitude ofof moremore thanthan 4343 kmkm.. TheThe coarsercoarser ashash particlesparticles fellfell 11 toto 22 weeksweeks afterafter thethe eruptions,eruptions, butbut thethe finerfinerashash particlesparticles stayedstayed inin thethe atmosphereatmosphere fromfrom aa fewfew monthsmonths upup toto aa fewfew yearsyears atat anan altitudealtitude ofof 1010––3030 kmkm..

•• PyroclasticPyroclastic flowsflows reachedreached thethe seasea onon allall sidessides ofof thethe 6060--kmkm--widewide volcanicvolcanic peninsulapeninsula..

MER and column height data from lithics clasts in fall deposit


Isopach Map(Volcanic ash fallout from the Tambora 1815 eruption)

The red areas show thickness of volcanic ashfall.The outermost region (1 cm thickness) reachedBorneo and the Sulawesi islands.

Contours show ash fall layer thickness, in cm

Deadly pyroclastic flows and pyroclastic surgesDeadly pyroclastic flows and pyroclastic surges(Effects of Plinian Eruption Mt Tambora, Indonesia April 10-11, 1815)

• 92,000 people killed – pyroclastic flows, p p py- 35% of the people on Sumbawa ( 48 000 in two years; 10 000 immediately and

38 000 from hunger and disease)44 000 L b k (160 k t th t)- 44 000 on Lombok (160 km to the east)

• Lost Town of Tambora; Pompeii of the east

Pompeii of the eastPompeii of the east

Lost Town of TamboraLost Town of Tambora(Tambora Kingdom)

There were three Kingdoms surrounding the Tambora volcano, Sanggar Kingdom on the northern foot, Tambora Kingdom on the western foot andthe Pekat Kingdom on the southern foot of Tambora volcano before 1815.

Archaeological evidence

• Carbonized human skeleton which wasstripped down and buried by pyroclasticsurge. This human skeleton was found in

Artifacts from Lost City of Tambora ExcavationDr. Haraldur Sigurdsson, University of Rhode Island

gthe kitchen area.


Carbonized building materials that was completely excavated near tambora village at the depth of 2 to 3 m beneath the surface.

BronzePorcelain

Clay bowls


Tambora Kingdom Cultural Affinities

Ceramics : Annamese (Vietnamese) affinityCeramics : Annamese (Vietnamese) affinity

Tambora Language : Mon-Khmer language group?(Dixon 1991)

Artifacts from Lost City of Tambora Excavation Dr. Haraldur Sigurdsson, University of Rhode Island

Tambora language

Tambora language was unique in the region. (Raffles, 1817)

Tambora Caldera

A sunset over Tucson, Arizona after the June 1991eruption of Mount Pinatubo displays vivid colorsand rays.

Global sunset color effects for months in 1815LongitudinalLongitudinal windswinds spreadspread thethe finerfiner ashash particlesparticles aroundaround thethe globe,globe, creatingcreating opticaloptical phenomenaphenomena.. ProlongedProlonged andand brilliantlybrilliantly coloredcolored

tt dd t ili htt ili ht f tlf tl ii L dL d b tb t 2828 JJ dd 22 J lJ l 18151815 dd 33 S tS t dd 77 tt 18151815 {G l d Al ksunsetssunsets andand twilightstwilights werewere frequentlyfrequently seenseen inin London,London, betweenbetween 2828 JuneJune andand 22 JulyJuly 18151815 andand 33 SeptSept andand 77 octoct 18151815.. {Greenland, Alaska,northeast Brazil, the tropical Atlantic, the eastern Pacific (the Galapagos Islands), India, Tibet, South Africa, and elsewhere}

The Global cooling in 1816

The eruption shot 400 million tons of sulfuricgases into the atmosphere, causing global coolingand creating what historians calland creating what historians call ............

“The Year Without a Summer”

• Farms in Maine suffered crop-killingfrosts in June, July and August., y g

• In France and Germany, grape andcorn crops died, or the harvests weredelayed.

• In Europe: High prices, food riotsI N E l d• In New England :- Snow in June and August, Frost

in July.- Exodus to Midwest

• Because of the bad weather a typhus• Because of the bad weather, a typhusepidemic broke out in Ireland, spreadto England and Scotland, and killed65000 people.

Global Surface Temperature Reconstruction

Mean Annual temperature at New Haven, CT 1790-1983

From Stommel and Stommel, 1979, Scientific American 240, 176-186.

Date of the grape harvest in Europe

I 1816 th ith f th i did t i f h ti til l t O t b


In 1816 the grape either froze on the vine or did not ripen for harvesting until late October

Acidity (sulfate) in Greeland ice core,from volcanic aerosol falloutfrom volcanic aerosol fallout

Tambora sulfate aerosolTambora sulfate aerosol deposition was59 kg SO4/km2 in Antarctic and 50 kg SO4/km2 in Greenland.50 kg SO4/km in Greenland.

Total aerosol mass :400 million tons H2SO42 4


Tambora sulfur in ice core

Tambora 1815Sulfur in glass inclusions inSulfur in glass inclusions in pyroxene

Total aerosol mass :400 Tg = 400 million tons


g

Glacial Ice Mercury Concentrations (1700-2000)

Other effect ;During the snowy summer of 1816 (the eruption of Mount Tambora in 1815 had blockedthe sky) Shelly visited Lord Byron. In the visit, Byron challenged and John WilliamPolidori (Byron’s physician) and Shelly to compose the scariest tale. Shelly come up the( y p y ) y p y pidea of Frankenstein, Byron wrote a fragment based on the vampire legend he heard inthe Balkans, from this Polidori later developed the novel “The Vampyre”.

“Frankenstein”• Author: Mary Shelly• Published in 1 Jan 1818• Original Name: “Frankenstein: The Modern Prometheus”• Classic Gothic and Romanic Novel, with a concern to

the “over-reaching” of scientism in the IndustrialRevolutionRevolution.

References• Papers/journals:

- Henry R. (2006). Indonesia finds its Pompeii. Chicago tribune, Online edition.- Melnik O (2006) “Physical Volcanology Course; Lecture 1” Institute of Mechanics Moscow State University- Melnik O. (2006). Physical Volcanology Course; Lecture 1 . Institute of Mechanics, Moscow State University.- Sigurdsson H. “Lost kingdom of Tambora”. Graduate School of Oceanography, University of Rhode Island- Sigurdsson H., Carey S. (1989). “Plinian and co-ignimbrite tephra fall from the 1815 eruption of Tambora

volcano”. Bull Volcanol 5: p.243-270.volcano . Bull Volcanol 5: p.243 270.- Sutawidjaja I.S., Sigurdsson H. and Abrams L. (2006). “Characterization of volcanic deposits and

geoarchaeological studies from the 1815 eruption of Tambora volcano”. Jurnal Geologi Indonesia 1 (1):49-57.- .......................................”The Eruption of Tambora in 1815 and the year without a summer”p y

• Pictures:- Artifacts from Lost City of Tambora Excavation Dr. Haraldur Sigurdsson, University of Rhode Island.

• Taken from many sources, such as:Taken from many sources, such as:---

http://www.uri.edu/news/tambora/artifact/pages/http://www.volcano.si.edu/index.cfmhttp://volcanoes.usgs.gov/ USGS Volcano Hazards Program

-• Comments & corrections to:

http://volcanoes.usgs.gov/ USGS Volcano Hazards Programwww.wikipedia.org

armstrong@students itb ac [email protected]

Structure of a VolcanoGeneric Structure of a Volcano• A volcanic vent is an opening exposed on the earth's surface where

volcanic material is emitted.All l t i t l t d l i th it t f th• All volcanoes contain a central vent underlying the summit crater of thevolcano.

• The volcano's cone-shaped structure, or edifice, is built by the more-or-less symmetrical accumulation of lava and/or pyroclastic materialaround this central vent system.

• The central vent is connected at depth to a magma chamber which isThe central vent is connected at depth to a magma chamber, which isthe main storage area for the eruptive material.

• Because volcano flanks are inherently unstable, they often containfractures that descend downward toward the central vent, or toward ashallow-level magma chamber.

• Such fractures may occasionally tap the magma source and act asy y p gconduits for flank eruptions along the sides of the volcanic edifice.These eruptions can generate cone-shaped accumulations of volcanicmaterial, called parasitic cones. Fractures can also act as conduits forescaping volcanic gases, which are released at the surface throughvent openings called fumaroles.

Types of Volcanoes

Types of volcanic eruptionsyp p

Explosive ExtrusivepGas-particle dispersion flows out

of the ventLava flows of domes


Explosive l ivolcanic

eruptionsp


Extrusivel ivolcanic

eruptionsp


Plinian EruptionsPlinian EruptionsPlinian eruptions are large explosive events that form enormous dark columns of tephra and gas high into thestratosphere (>11 km)stratosphere (>11 km).Such eruptions are named for Pliny the Younger, who carefully described the disastrous eruption of Vesuvius in 79 A.D.This eruption generated a huge column of tephra into the sky, pyroclastic flows and surges, and extensive ash fall. Manythousands of people evacuated areas around the volcano, but about 2,000 were killed, including Pliny the Older.

Some plinian eruptions inject such largetiti f l ( ll li id d l t )quantities of aerosols (small liquid droplets)

into the stratosphere that surfacetemperatures on earth may decrease slightly.The 1991 eruption of Mount Pinatubo,The 1991 eruption of Mount Pinatubo,Philippines, and the 1982 eruption ofEl Chichón, Mexico caused temperaturesworldwide to decrease slightly.Th i 1815 ti f M tThe massive 1815 eruption of MountTambora volcano, Indonesia, is thought tohave caused the 1816 "Year without aSummer" in the northeastern U.S., Canada,Su e e o eas e U S , Ca ada,and western Europe.

Classes of EruptionClasses of EruptionType Lava Volcano EffectsType Lava Volcano Effects

Icelandic Basalt None or Shield Fissure Flows

Hawaiian Basalt Shield

Strombolian Basalt- Small Mild, ContinuousAndesite Stratovolcano

Vulcanian Andesite Stratovolcano Large eruption cloud

Plinian Andesite –Rhyolite

Stratovolcano Pyroclastic Flows

Caldera-Forming(Ultra-Plinian)

Rhyolite Stratovolcano or None

Large PyroclasticFlows

Phreatic Any Any Steam BlastPhreatic Any Any Steam Blast

Volcanic MaterialsThe products of volcanic eruption take three forms:• Lava flows – Sheets of lava that move over the ground• Pyroclastic debris – Fragments blown out of a volcano that fall and accumulate.• Volcanic gases – Vapor and aerosols that exit a volcano.

Pyroclastic flowsPyroclastic flows• Mixtures of hot rock, ash, and gases that sweep down sides of a volcano at high speeds. Move as fast

as 100 km/hr with temperatures of several hundred degrees Celsiusas 100 km/hr with temperatures of several hundred degrees Celsius.• Produced by explosive eruptions or when a dome or thick lava flow collapses down a steep slope.

Most pyroclastic flowsMost pyroclastic flowsconsist of two parts:(1) a basal flow of

coarse fragments coarse fragments that moves along the ground.

(2) a turbulent cloud of ( )ash that rises into the air.

Pyroclastic flows (Mt. Bulusan, Philippines )

Effects of Pyroclastic Flows

Destroy structures by direct impactEl Chichon, Mexico, 1982

Bury sites under hot volcanic debrisPinatubo, Philippines, 1991Pinatubo, Philippines, 1991

Rapidly melt snow and ice to produce laharsRedoubt Alaska 1989Redoubt, Alaska, 1989

Effects of Pyroclastic Flows

Burn trees crops and buildingsBurn trees, crops, and buildingsSoufriere, Montserrat, 1997

Results are deadly if a pyroclastic flow sweeps through a populated area.Mt. Pelée, Martinique, Caribbean. May 8, 1092

Pyroclastic flow generated by collapse of lava dome destroyed town of St. Pierre.29,000 killed2 survivors

The Volcanic Explosivity IndexThe Volcanic Explosivity IndexVEI Tephra volume

(m3) Eruption column height

Stratospheric injection

General description( ) co u e g t

(km) ject o desc pt o

0 < 104 < 0.1 None Non-explosive 4 61 104-106 0.1 –1 None Small

2 106-107 1 – 5 None Moderate 3 107 108 3 15 P ibl M d t l3 107-108 3 – 15 Possible Moderate-large4 108-109 10 – 25 Definite Large 5 109- 1010 > 25 Significant Very large5 10 - 10 > 25 Significant Very large6 1010-1011 > 25 " " 7 1011-1012 > 25 " "8 > 1012 > 25 " "

Structure of Atmosphere

From Cunningham & Cunningham, 2004, Fig. 9.1

(Ma)

Geologic Time Scale

Comparisons

100 a = 1 a = 1 year101 a = 1 decade101 a = 1 decade102 a = 1 century103 a = 1 ka = 1 milennium106 a = 1 Ma = 1 megennium10 a = 1 Ma = 1 megennium107 a

8108 a = 1 geon109 a = 1 Ga = 1 gigennium10 a 1 Ga 1 gigennium

mt. tambora " the largest volcanic eruption in recorded history "

Technology

ma reef limestones

early pleistocene volcanoes

middle miocene

coral reef limestone

barberi t

pliocene volcanoes

older volcano

sumbawa island sumbawa