Ontake 2014

When was the eruption?

September 2014

What was ejected from the volcano?

ash, rocks, and pyroclastic material.

How high did the eruption plume rise?

The eruption plume rose over 11 kilometers into the atmosphere.

How many died?

63

Who was primarly injured and killed?

Hikers and climbers

How many were seriously injured?

Over 40 people were seriously injured

How deadly was this eruption in Japan's history?

The deadliest volcanic disaster in Japan since 1926.

Why was it so deadly?

Hikers were unprepared for the eruption and underestimated the risks involved and the eruption was not detected and it was a phreatic eruption.

What is a phreatic eruption?

Phreatic eruptions are steam-driven and occur when groundwater or surface water comes into contact with hot rock or magma. This super heats the water, causing rapid steam expansion and an explosion.

Who performed search and rescue?

Over 1,000 personnel, including SDF, police, and fire departments, participated in rescue efforts.

What made rescue operations difficult?

Ongoing eruptions and the risk of further explosions hampered operations.

Thick ash and toxic gases necessitated the use of specialized equipment, such as gas masks.

What did ashfall do?

Ashfall affected roads and blocked hiking trails, hindering rescue efforts.

How much material was ejected?

Approximately 1 million cubic meters of ash and debris.

What was the speed of falling rocks?

Estimated at over 300 km/h, causing devastating injuries.

What was the temperature of ash and debris?

Exceeded 100°C near the eruption site.

How many people were on the mountain?

Hundreds of climbers were on the mountain at the time; many were rescued or found shelter.

What were rescue and recovery costs?

Around 46 million US dollars

How many helicopters were used?

20 Helicopters were deployed in rescue efforts

How much did tourism drop?

Visitor numbers decreased by 30-40% in the months following the eruption in the region after.

What were estimated losses to local tourism businesses?

14 million US Dollars

What was total economic cost?

Around 110 million US Dollars

What was done to improve volcanic detecting?

Additional seismometers, gas analyzers, and ground deformation sensors were installed around Mount Ontake and other active volcanoes and real time data sharing between local authorities, the Japan Meteorological Agency (JMA), and researchers.

Was any foreign aid needed?

Japan did not receive any significant aid as Japan has a robust economy and the disaster was manageable for Japan

What was done to improve citizen safety in the future?

Regular volcanic eruption drills involving local governments, rescue teams, and residents were implemented and public awareness plans were implemented

What was done for hiker safety in terms of monitoring and kit requirements?

In some areas, climbers were required to register before ascending, allowing authorities to track their movements in emergencies and hikers were encouraged to carry helmets, masks, and first aid kits when climbing active volcanoes

What was the eruption on the VEI scale?

3