Hazardous Earth Case Studies Flashcards
General Volcanic Eruptions
- Mount Vesuvius AD79- killed 16,000 people and destroyed all of Pompei via pyroclastic flows.
- Klyuchevskaya Sopka, Kamchatka Peninsula, no economic or social effects as no one lives in the area. Kambalny volcano, phreatomagmatic eruption create pillow lavas, creating lava fields, making the land barren.
- Baroarbunga volcano, Iceland, six month effusive fissure eruption, 2014-15 ejected 1.6km^3 of lava, created few hazards.
- Mount St Helens eruption 1980, 1.6km^3 of tephra, caused the north side of the volcano to collapse, and created vast pyroclastic flows and ash fall killing 57.
- Yellowstone supervolcano, would eject 1000 cubic kilometres of tephra, causing buildings to collapse in the US and block the sun’s radiation causing global food shortages and mass starvation.
- Nyriagongo volcano in the Democratic Republic of Congo, 2002 led to basaltic lava flows into the city of Goma killing 147 people and destroying 1/3 of the city.
General Volcanic Eruptions
- Cameroon, Lake Nyos, no effective monitoring of Oku Volcanic field, limnic eruption, carbon dioxide suffocated 1,700 people within 25km, mostly villages.
- Mount Etna, Sicily, large earth barrier created to divert the highly viscous rhyolitic lava flow away from the city Zafferana. Concrete blocks were dropped also.
- Krakatoa, Indonesia (1883), pyroclastic flows and tsunami across the water to Sumatra killing 36,000 people. Anak Krakatoa (2018).
- Nevada del Ruiz, Colombia, eruption in 1986, killed 23,000 people.
- Eyjafjallajokull eruption in 2010, no deaths, grounded flights across Europe.
- Indonesia 1991, Philippine Government created a 20km exclusion zone around Mt Pinatubo saving 5000 lives.
Japan Tectonics
Located in one of the most tectonically active zones in the world, 4 tectonic plates, 12,000 eruptions over the past 2000 years. Culture based around volcanoes.
Mount Ontake- Erupted 27th September 2014, the volcano was not under any alerts. The eruption killed 63 people, large areas were covered by ash fall, pyroclastic flows, volcanic bombs and lahars.
Japan has 400 earthquakes a day, since 2000, 23 earthquakes of 7.0Mw occurred causing 16,000 deaths.
The Great East Japan Earthquake, Tohoku, 2011, 9.0 Mw, lasted 6 minutes and created a large tsunami. Explosion of Fukushima nuclear power plant.
16,000 deaths, injured 6,000, 2/3 over the age of 60. 100,000 children affected, 2,000 orphaned.
Cost of earthquake nearly £181 billion, 47,500 buildings destroyed, 143,300 damaged. 4.4 million lost electricity.
Government injected billions into economy for stability.
Indonesia Tectonics
Surrounded by several tectonic plate boundaries. More than 3/4 of Indonesia’s population live within 100km of a volcano that erupted in the past 10,000 years.
Mount Merapi - 26th October and 12th November 2010. VEI 4 eruption created large pyroclastic flows, lahars and acid rain was created due to it being the rainy season. Overall 367 people were killed, 277 injured. 410,000 became refugees, infrastructure and crops destroyed.
Indonesia have a Centre for Volcanology and Geology Hazard Mitigation (CVGHM), established in 1920. Monitors 60 of Indonesia’s volcanoes. They work with governments on mitigation strategies such as local preparedness.
Indonesia have well trained search and rescue, including military, as well as temporary shelters.
Nepal Earthquake
Nepal situated between a collision zone between the Indo-Australian plate and Eurasian plate.
The Gorkha Earthquake, 2015, 7.8Mw, caused avalanches on Everest. 8,000 deaths, over 22,000 people injured.
2.8 Million displaced from Kathmandu valley. 473,000 houses damaged/destroyed. Cost of earthquake $10 billion, created food insecurity as it disrupted growing season. Created more political instability.
The National Society for Earthquake technology (1993) and the Disaster Preparedness Network (1996). They map high risk areas, introduced building codes, encouraged a go-bag for a disaster, education programmes.
International disaster relief agencies mitigate the effects of earthquakes. 330 NGO’s after 2015 earthquake.
General Earthquakes
Tangshan, China Earthquake, 1976, 255,000 dead.
Kobe Earthquake, 1995, death of more than 5,000 people.
Earthquakes in the Kamchatka Peninsula, Eastern Russia.
Italy Volcanic Activity
Italy have had success diverting the flow of lava using earth barriers and large concrete blocks.
Their monitoring system is highly effective (CFCRV)- They analyse eruption patterns of volcanoes, comparing Italy’s eruptions with other eruptions around the world. A good alert system and research into buildings designs resistant to ash fall. Italian government has the resources to compensate individuals and businesses affected by the volcanoes, as the effects of the volcanic eruptions aren’t large due to the mitigation strategies.
Japan
They have high level research and monitoring of earthquakes- the Japan meteorological Agency (JMA) mitigates earthquakes and tsunami’s.
Buidings with aseismic design eg steel frames, braces and rubber shock absorbers.
Fire-proofing older buildings, land-use zoning, tsunami and earthquake warning systems. Refuge sites around Japan. Education and training for earthquakes.
Japan has well rehearsed recovery and reconstruction plans at national, regional and local levels.
