Implications of living in tectonically active locations: Japan (Mt. Ontake) and Indonesia (Mt. Merapi.)
4.a. There are a range of impacts people experience as a result of volcanic eruptions.
Backgroun Strato volcano 200km west of Tokyo, rises 3000m with a snow Strato volcano rising 3000m.
d covered summit.
Dormant for centuries until sequence of eruptions between Oct VEI 3 eruptions in 1994, 1997, 2001, 2006 and VEI 4 in Oct and Nov
1979 and April 1980. VEI 3 Sept 2014 2010.
Phreatic (steam) eruptions in 1991 and 2007, not particularly Eruption at start of rainy season triggered lahars fed by ash, dome
explosive, but ash, gas and pyroclastic flows. developed in crater which eventually collapsed causing pyroclastic
flows.
Tectonic Very tectonically active as 4 plates meet causing subduction Widespread subduction along entire archipelago, North Australian
setting leading to intense volcanic activity. Ring of Fire convergent plate Continental Shelf in collision with Eurasian plate so high level of
boundary. volcanism. Large number of highly explosive eruptions- cataclysmic
Around 1200 eruptions in last 2000 years. 1883 Krakatau eruption and tsunami.
Social Violent eruption without any warning/ alerts, however some
impacts reported increase in earthquake activity.
Killed 63- most casualties climbers/ hikers, but 200 survivors Killed 367, 77 injured.
made it down the mountain.
Large surrounding area affected by ash fall, pyroclastic flows, Pyroclastic flows extended up to 15km in some directions. Lava bombs
volcanic bombs and lahars. thrown in all directions 4km from summit.
Lahars fed by ash from earlier eruptions due to rainy season. Volume of
material combined from ash and pyroclastic flows 130 million m3.
Destroyed crops, livestock and infrastructure (buildings, power lines,
bridges.)
Toxic fumes and ash risked health. SO2 emissions caused acid rain over a large area.
Search and rescue teams deployed.
Refugee churches/ shelter, homeless and distressed people. 410,000 became refugees.
Economic Mt Ontake ski resort delayed opening 2 months as slopes within Yogyakarta Airport closed for over 2 weeks due to ash fall.
impacts 4km exclusion zone. Planes grounded in Western Australia, planes grounded due to ash
Hotels and restaurants struck with cancellations. cloud being a risk to aircraft damage.
Air travel stopped, disrupting trade and tourism.
Ash damaged agriculture: settled on Chinese cabbage crops, Crop damage increased veg prices.
delaying shipping.
Unexpected, so neighbouring areas unprepared for devastation. People, mainly farmers, lost homes and livelihoods.
Political Prime minister Shinzo Abe ordered military assistance with Gov discouraged people from returning to Srunen area, as an incentive,
impacts emergency rescue operations. they proposed providing $3,200 and a small plot of land as an
incentive.
Families of victims filed a lawsuit against country/ local area
seeking damages of £150 mill in 2017. Cost gov lots in damages
from eruption, locally and nationally.
Environ- Magma destroyed crops and agriculture, contaminating air and 130 million m3 pyroclastic flows contributed to the death of livestock.
mental water. Ash covered crops. They covered crops and travelled down the mountain.
impacts Heavy toxic ash covered much of volcano.
Heat from eruption melted surface snow causing dangerous Volcanic bombs and gases up to 800oC spread 11km
slides/ falls down mountain.
Why live in Many volcanoes that historically erupted are no longer/ rarely active.
areas of Fertile soils for agriculture- weathered lava products and ash Ash from eruptions causes more fertile soils.
risk? support intensive agriculture. Economic opportunities
Mt Fuji and other peaks important part of country’s culture,
tradition, myth and legend.
Popular with tourists, climbers and hikers. Facilities like lodges Conservation area set up where unsafe to live.
close to summit, settlements on summit and place of
pilgramige.
