Volcanic Hazards

Anmerkungen:

• Streams of molten rock Causes extensive damage or total destruction by burning, crushing or burying everything in their paths

1. Speed of lava flow

   Anmerkungen:

   • 1. Type of lava erupted 2. Steepness of ground 3. Rate of lava producection
2. Effects of lava flow

   Anmerkungen:

   • Bury homes and agricultural land Block roads and highways that may serve as the only evacuation route -> people die

Anmerkungen:

• High density mixtures of hot, dry rock fragments and hot gases that move away from the vent at high speeds Two parts: Basal flow of coarse fragments and a turbulent cloud of ash above it

1. Speed

   Anmerkungen:

   • SUPER FAST!!!! 30m/sec up to 30~30km from the source
2. Effect

   Anmerkungen:

   • Destroys nearly everything in its path Knock down, shatter, bury or carry away all objects and structures in their way Cause combustible material to burn

Anmerkungen:

• Fragments of volcanic rock and lava regardless of size that are blasted into the air by explosions 2mm to 1m in diameter

1. Effects

   Anmerkungen:

   • Death - direct exposure to tephra Roof and building collapse Damage public utilities Damage agricultural land Respiratory problem Power facilities shut down Roads become impassable coz ash is slippery Waste water system may clog

Anmerkungen:

• Water vapour, carbon dioxide and sulfur dioxide

1. Effects

   Anmerkungen:

   • SUPER HAZARDOUS SO2 Lowering of surface temp Depletion of ozone layer

Anmerkungen:

• Hot or cold mixture of water and rock fragments 

1. Speed

   Anmerkungen:

   • Varies
2. Formation of Lahar

   Anmerkungen:

   • 1. From heavy rainfall on loose volcanic debris 2. Rapid melting of snow and ice 3. Volcano erupts through a crater lake

Anmerkungen:

• Huge sea wave

1. Formation of Tsunami

   Anmerkungen:

   • 1. Earthquake beneath the ocean 2. Earthquake must be strong, at least 6.5  3. Earthquake must rupture the Earth's surface 4. Eqarthquake must cause vertical movement
2. Effects of Tsunami

   Anmerkungen:

   • Objects are lifted and carried inland by waves Destruction to buildings

Anmerkungen:

• Ash particles collecting waterdroplets causes condensation and forms unexpected heavy rain

1. Effects

   Anmerkungen:

   • Can form lahar Stream explosions Acid rain

Anmerkungen:

• Earthquake under the volcano Collapse of slop

1. Formation

   Anmerkungen:

   • 1. Explosive eruptions 2. Intrusion of magma into a volcano 3. Large earthquake directly below or nearby a volcano 4. Intense rainfall that saturates ejected volcanic materials may move downslopes due to increased pore water pressure causing landslides
2. Effects

   Anmerkungen:

   • 1. Death 2. Debris avalanche leading to lahar 3. Debris avalanche leading to volcanic eruption

Anmerkungen:

• Coz of sulfur compounds into the Earth's atmosphere

Anmerkungen:

• 1. Lowering of global temperature (Volcanic ash can cause reflection of solar radiation and causes temp to be cooler) 2. Increase in temperature (greenhouse gases)

Anmerkungen:

• Crops die Humans die Everybody die Breakdown of swwage system

1. Recurrence Interval

   Anmerkungen:

   • Measure of the frequency of occurrence of an event base on historical records
2. Seismic Monitoring

   Anmerkungen:

   • Seismic activity is common near volcano The frequency and intensity of the tremours will increase when magma is approaching
3. Monitoring of Ground Deformation

   Anmerkungen:

   • Using tiltmeters and Electronic distance measurement instrument
4. Monitoring of Gas Emissions and other Precursor Phenomenon

   Anmerkungen:

   • Direct gas sampling and lab analysis Continuous on site sampling through sensors
5. Remote Sensing

   Anmerkungen:

   • Statellite

1. Modifying the Event
   1. Lava dam and artificial barriers

      Anmerkungen:

      • Block the flow of the lava and divert it away Problem Expensive Lava flow can change path too Need to be at least 30m high to withstand the speed and strength of pyroclastic flows Eg. Japan
   2. Bombing

      Anmerkungen:

      • Divert flow Alter the topography Eg. Mount Etna 30% of flow diverted
   3. Water spray

      Anmerkungen:

      • Cools the lava and forms internal barriers within the flow and divert the flow elsewhere
   4. Hazard resistant design

      Anmerkungen:

      • Strong and steep sloping roof so that ash can shed off easily Requires $$$$$ and cordinated efforts between govt and the people
2. Modifying the Vulnerability

   Anmerkungen:

   • Depends on weath and technical ability of the country, level of education and awareness and degree of effectiveness of collaboration of different stakeholders
   1. Prediction and warning

      Anmerkungen:

      • Only accurate to some extent Economic and social costs if evacuation was for nothing May cause distrust too
   2. Community preparedness

      Anmerkungen:

      • Advanced preparation and management structures to organise the evacuation, temp housing food etc are needed Public education and awareness programmes
   3. Land use planning

      Anmerkungen:

      • Land use using hazard zoning maps as a basis  Problems Only an estimation, base on assumption that future eruptions will behave in a similar manner Many countries do not have maps and accurate past records needed Not applicable to existing developments
3. Modifying the Loss
   1. Aid and insurance

      Anmerkungen:

      • Insurance -> to spread the costs incurred
      1. Technical aid

         Anmerkungen:

         • For monitoring and forecasting eruptions
      2. Financial aid

1. Community Preparedness
2. Provision of support services for refugees

   Anmerkungen:

   • Transportation Medical treatment, shelter Clean drinking water Medical personnel Psychological and emotional care Ressettlement issues