### b. Measures Against Ash Falling due to Active Volcanoes

Since the ash falling on roads due to volcanic eruption has a great social impact, such as traffic obstruction, a framework is being developed in order to remove ash quickly and appropriately from roads using street sweepers.

### c. Japan Meteorological Agency Initiatives

To prevent and mitigate volcanic eruption disasters, domestic volcanic activity is monitored and volcanic warnings are issued in a timely manner. Especially for the 47 volcanoes in need of more intensive monitoring/observation for volcanic disaster mitigation selected by the Coordinating Committee for Prediction of Volcanic Eruptions, observation facilities have been deployed and volcanic activity is being monitored around the clock.

Also, volcanic alert levels are being applied and improved through coordination of evacuation planning at local Volcanic Disaster Mitigation Councils (applied to 30 volcanoes as of the end of March 2015).

### Eruption of Ontakesan (Mt. Ontake) on September 27, 2014 and Response by Japan Meteorological Agency

Ontakesan (Mt. Ontake) erupted at about 11:52, September 27, 2014. The smoke emitted from this volcano flowed eastward and rose to an estimated height of about 7,000 m above the crater rim. In addition, the survey conducted by a relevant organization showed that large cinders were scattered about 1 km from the crater row and pyroclastic flows reached about 2.5 km to the southwest and about 1.5 km to the northwest. This eruption of the Ontakesan is the first one after the very small eruption occurred in March, 2007.

In consideration of the eruption, the Japan Meteorological Agency (JMA) issued Near-crater Warning at 12:36 on the same day, and raised the volcanic alert level from 1 (Normal Note) to 3 (Do not approach the volcano). After that, on January 19, 2015, in consideration of the Coordinating Committee for Prediction of Volcanic Eruption's opinion that the volcanic activity had reduced, JMA reduced the area in which caution is required against eruption to the 3 km area around the crater.

Since the eruption occurred around noon during the tourist period, a lot of climbers visited the area near the mountaintop. The Fire and Disaster Management Agency reported that the total number of missing and dead was 63 persons (as of October 23, 2014) and it was the greatest among the numbers of missing and dead due to volcanic disasters after World War II.

JMA took special notice of loss of many lives due to this eruption, and therefore conducted study about the observation framework for grasping the symptoms of phreatic eruptions and changes in volcanic activity as well as provision of easy-to-understand information to climbers and sightseers in the “Conference for Reviewing Volcano Observation Framework, Etc.” and “Conference Concerning Provision of Volcano Information” under the Coordinating Committee for Prediction of Volcanic Eruptions. The committee summarized an urgent proposal in November 2014 and a final report in March 2015. In response to this, JMA is making efforts to strengthen the volcano observation framework by installing volcano observation facilities for the volcanos requiring constant observation throughout the country as well as provide easy-to-understand information.