Volcanic Hazard, Risk, Disaster

7/23/2019 Volcanic Hazard, Risk, Disaster

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1. Occurrence and distribution: relate to plate tectonic zones & movement;

relate to fault structure

material: lava and tephra (pyroclastic material) or ejecta

menta.2. Classification:

Period of activity: active, dormant or extinct.

Type of activity: Pelean

Vesuvian

Strombolian

Hawaiian

Icelandic





1. Cinder cone

2. Shield volcanoes

3. Stratocones=composite volcanoes = stratocalnoes

4. Bocca

5. Caldera

6. Volcanic domes

7. Extrusive & intrusive

8. Flood basalt

9. Block lava

10. Aa flow

11. Pahoehoe







Mount Semeru (photo: Julie Morin)


http://slidepdf.com/reader/full/volcanic-hazard-risk-disaster 8/40Gunungapi Semeru (Sumber Franck,L. 2005)



1. Benefits2. Weather effect3. Cataclysmic eruption4. Lava flow

5. Ash flow6. Nue ardente7. Tephra falls8. Lahars

9. Poisonous gases10. Flood from glaciers outburs11. Earthquake12. Massmovement



Foto bentuklahan vulkanik rawan erosi dan longsoran



Clearing of recent forests (Kali Konto Project. 1980’s)



Terrasse construction for commercial crops



South flank of Mount Arjuno, November 2002 (source: Jasatirta)









1. Evaluation to determine hazard susceptibility: Geomorphological approach Terrain classification and evaluation

2. Approaching volcanic activity: Changes in characteristics and behavior of fumarol, hot

springs, crater lakes; Changes in the strength and orientation of the earth’s

magnetic field;

Increased geothermal heat flow from the area;

Alteration in local electric currents within the earth;

Bulging upward of the volcano due to magma buildup;

Erratic behavior of animals and other signals indicative ofpossible impending earthquake activities.





Table 1



1. V1: Crater2. V2: Volcanic cone3. V3: volcanic slope4. V4: Volcanic foot5. V5: volcanic foot plain

6. V6: Fluvio volcanic foot plain7. V7: Lava field8. V8: Lava flow9. V9: Lahar flow10. V10: Intermountain plain11. V11: Volcanic neck12. V12: Parasite cone13. V13: Baranco



1. Based eruption type Icelandic

Hawaiian

Strombolian

Vulcanian Vesuvian

Plinian

Pelean

2. Based on lava type Volcano with basic lava

Volcano with medium lava

Volcano with acid lava



1. Lava shield2. Lava dome

3. Lava cone

4. Lava mound

5. Lava disc

1

2

3

4

5



1. Cumulo-dome = mamelon2. Tholoid

3. Plug dome1

2

3



Lima tipe

a. Scoria cone

b. Scoria

mound

c. Maar

d. Nestedscoria cone

e. Strato

volcano



1. Shape2. Surface configuration

3. Break of slope

4. Drainage pattern5. Size

6. Site

7. Association features

8. Land cover/land use



1. Occurrence: Rising magma to the Earth’s surface

Type of volcanic activity:

Explosion

Central eruption Fissure eruption

2. Type of volcano Shield volcano

Strato or composite volcano

Bocca volcano





4.3 Comparison of three type of volcanoes



4.4 Phenomena of strato volcano/composite volcano

1. Ash cloud2. Crater

3. Dome

4. Vent

5. Lava flow6. Secondary vent

7. Fissure

8. Sill

9. Dyke10. Magma chamber

11. Thermal flume



1. Volcanic earthquake

2. Pyroclastic falls

3. Lava flow

4. Nue ardente or glowing cloud

5. Collapsing of lava dome6. Hot lahar flow

7. Rain lahar flow

8. Subsidence

9. Toxic gas



Factor affecting the hazard in Dieng

1. Climate condition

2. Geology

3. Geomorphology

4. Soil type

5. Land use

6. Social-economic condition









1) Direct hazard

2) Indirect hazardlangsung:

3) Toxic gases

4) Environmental degradation5) Pollution



1) CO2 Gas

2) Lahar flow

3) Mud flow

4) Flash flood

5) Landslide

6) Air pollution volcanic eruption

7) Erupsi gunungapi8) Eartquake



Occurrence of toxic gas disaster of Dieng







1. Type of the volcano2. Relief3. Slope4. Geological structure5. Landform condition6. Rainfall7. Wind

8. Drainage pattern and density9. Morphometry of the valley10. Land use or land cover.

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Volcanic Hazard, Risk, Disaster