Mount Ontake 2014

• Location


  Japan, Honshu Island. Part of the Ring of Fire.
• Cause


  Philippine plate subducting under Eurasian plate. Phreatic eruption.
• Phreatic Eruption


  • Steam driven eruption caused when magma superheats water in the volcano and turns it to steam. Cannot be predicted.
• General Information: Saturday 27th September 2014, only 10-20% of hikers registered, 250 tourists.
• Primary Impacts


  • 15cm of ash deposited
  • Lapilli at up to 300km/h hit people and huts
  • Hydrogen sulfide toxic gas
• Secondary Impacts


  • Water from Cyclone Phanfone mixed with ash to form lahars (5-6th Oct)
• Social


  • 60 killed
  • 40 injured
• Economic


  • Tourism increased due to notoriety
  • Agriculture suffered
• Environmental


  • Cabbage farm destroyed
• Responses


  1. ~1000 workers sent out for search and rescue that had to be stopped a few days later due to dangerous levels of toxic hydrogen sulfide gas

  2. Hikers now must register at the bottom before hiking up Mount Ontake

  3. Hikers will receive a leaflet with evacuation routes when registering

  4. Mount Ontake was closed for several years after the eruption

  5. Mount Ontake is constantly monitored