Lessons from Mt. Ontake ... Although we want to make use of it ... Challenges to 23% of volcanoes nationwide | NHK News

Lessons from Mt. Ontake Though I want to make use of it ... Challenges to 23% of volcanoes nationwide September 27 18:24

“Extraordinary” commentary on changes in volcanic activity introduced by the Japan Meteorological Agency based on the lessons of Mt. Ontake. The country requires local governments around the volcano to consider in advance the methods known to climbers and residents, but over 20% of the nationwide volcanoes that the Japan Meteorological Agency is constantly monitoring , I found out that the well-known method was not specifically decided.

The lesson learned from the eruption of Mt. Ontake five years ago, the Meteorological Agency is to announce commentary clearly stating “temporary” when there is a change in volcanic activity. The volcano disaster prevention council, which is made in Japan, is requested to consider in advance how to communicate this information when it is announced.

However, NHK interviewed 47 volcanic disaster prevention councils nationwide that are constantly monitored by the Japan Meteorological Agency, and in 11 volcanoes that accounted for about 23%, the methods to be known to climbers and residents were specifically decided. I understood that it was not.

The reasons for this are “under consideration”, most of which are “no need”, “no disaster prevention measures such as the eruption warning level are shown, and I do not know how to accept” There was also a voice.

In addition, 36 volcanoes are supposed to have known methods, but 14 of these volcanoes are not described in “evacuation plans” that show the disaster prevention measures of local governments. The question remained whether it could be used.

Associate professor Yasunori Tsuji of Yamanashi University, who is familiar with volcanic disaster prevention, said, “The extraordinary information does not indicate a uniform disaster prevention response like the eruption warning level, so the local government must make a judgment on a case-by-case basis. However, local governments are lacking in specialized knowledge and know-how, which is a burden and leads to delays in responding to the situation. Pointed out.

11 volcanoes for which well-known methods are not specifically determined

When NHK interviewed the Volcano Disaster Prevention Council, etc., the following 11 volcanoes did not have a specific method for disseminating “temporary” commentary.

Hokkaido's ▽ Tarumae Mountain, ▽ Tatara, Nagano and Gunma prefecture border ▽ Asamayama, Toyama prefecture ▽ Miyagahara, Shizuoka prefecture Izu ▽ Izu eastern volcano group, Izu Islands ▽ Niishima, ▽ Kozushima, ▽ Miyakejima, ▽ Hachijojima, ▽ Aogashima, Kagoshima Prefecture ▽ Satsuma Iwojima.

14 volcanoes not yet described such as evacuation plan

On the other hand, although the well-known method has been decided, the following 14 volcanoes are not described in the “evacuation plan” indicating the disaster prevention measures of the local government.

Hokkaido's ▽ Atosanupuri and ▽ Meakandake, ▽ Daisetsuzan, ▽ Usu, ▽ Esan, Aomori and Akita prefecture border ▽ Towada, Akita and Iwate prefecture border ▽ Akita Komagatake, Akita prefecture ▽ Akita Yakeyama, Miyagi At the border between Yamagata and Yamagata ▽ At the border between Mt. Zao and Gunma ▽ At the border between Kusatsu Shirane, Niigata and Nagano ▽ At the border between Niigata Yakiyama and ▽ Izu-Oshima, Kagoshima and Miyazaki ▽ Mt. Ryobu Island,

Information on evacuation plans, etc. that are known to the public. 22 volcanoes

The following 22 volcanoes clearly stated how to provide temporary commentary information in the “evacuation plan”.

Hokkaido's ▽ Tokachidake, ▽ Hokkaido Komagatake, Aomori Prefecture's ▽ Hakkoda, ▽ Iwaki, Iwate Prefecture's ▽ Iwate, Miyagi and Iwate, and Akita's prefectural border ▽ Kurikoma, Yamagata and Akita's prefectural border At the border between Fukushima and Yamagata ▽ Azumayama, Fukushima Prefecture ▽ Adara Tarayama, ▽ Bandai Mountain, Tochigi and Fukushima Prefecture border ▽ Nasudake, Tochigi and Gunma prefecture border ▽ Nikko Shirane, Nagano and Gifu On the prefectural border, Mt. Ontake, ▽ Yaketake, ▽ On the prefectural border between Mt. Norikura, Ishikawa and Gifu ▽ On the border between Hakusan, Shizuoka and Yamanashi ▽ Mt. Fuji, Kanagawa Prefecture, Mt. Hakone, Oita Prefecture, ▽ Tsurumi-dake, Mt. Mountains, Mt. Aso in Kumamoto Prefecture, and Mt. Unzen in Nagasaki Prefecture.

Sakurajima and Suwanosejima in Kagoshima Prefecture have been excluded from coverage because the level has never been 1 since the eruption warning level was introduced 12 years ago.

What is “Extraordinary” Commentary?

“Extraordinary” commentary that indicates changes in volcanic activity has been announced since the eruption of Mt. Ontake.

Five years ago, Mt. Ontake had the lowest eruption alert level, but because of the increase in volcanic earthquakes, the Japan Meteorological Agency, for three times, 16 days before, 15 days before, and 11 days before, Announced information on the activity status of the volcano called “commentary information”.

However, this information was not fully communicated to climbers.

For this reason, the Japan Meteorological Agency will not raise the eruption warning level, but if there is an unusual change in volcanic activity such as “increased volcanic earthquakes”, “increased volcanic gas”, or “crustal deformation”, ”Will be announced.

“Extraordinary” commentary has been in operation since May 2015, the eruption of the eruption, and has been announced 268 times at 16 volcanoes nationwide by the 26th.

It has been announced on Mt. Aso in Kyushu, Mt. Shinmoe in Kirishima Mountains, Mt. Kuju, Mt. Hakone in Kanagawa Prefecture, and Mt. Azuma in Tohoku.

Local governments struggling to deal with the announcement of “temporary” commentary

In fact, there are local governments who have had difficulty in responding to the fact that “temporary” commentary has been announced at local volcanoes. It is Kamifurano town at the foot of “Tokachidake” located in the center of Hokkaido.

At Tokachidake, the Japan Meteorological Agency announced “extraordinary” commentary on June 11 that last year, volcanic earthquakes increased in the shallow vicinity of the “6-2-2 crater” and volcanic tremors were observed.

The volcano disaster prevention council, which is created by the local governments around Tokachidake, is positioned in the “evacuation plan” to inform tourists and climbers when temporary information is announced.

For this reason, Kamifurano-cho also called for attention on the homepage, created flyers and distributed them to tourist facilities and convenience stores.

Before opening the mountain Difficult for safety and tourism

However, Kamifurano Town was facing another problem at this time.
I was refraining from the “mountain opening” tourism event to announce the arrival of the summer climbing season in six days.

Sightseeing on Tokachidake is one of the major industries for Kamifurano Town, and in “Yamakiri”, a large number of climbers visiting from all over the area walked around the crater to reach the summit.

Although "extraordinary" commentary has been announced, the Japan Meteorological Agency's "eruption alert level" remains at the lowest level, and there is no indication of the range that requires attention.

What should we do to balance “safety” and “tourism”?

Town disaster prevention officers and tourism associations had to make their own decisions.

As a result of repeated discussions, the mountain-climbing climbing course was greatly changed to a course that does not pass near the crater, and a helmet was rented out to the participants before being carried out.

The new course is to use a mountain trail opposite the crater and walk on a mountain trail that is more than 2 km away from the crater, farther than the regulation range required for eruption alert level 2. .

Mr. Tomoyuki Sakurai, the disaster prevention manager of the Kamifurano-cho General Affairs Division, said, “Because the eruption warning level is 1, it could not be said that we would not go to the course walking near the crater, but the level could rise in the middle of“ mountain opening ” Yes, it was difficult to judge. ”

Mr. Koichi Nagata, Executive Director of Kamifurano Tokachidake Tourism Association, said, `` I wanted to do it on a course aiming for the summit if possible, but if I look back on the eruption of Mt. I changed the course with the first priority. "

Although specific disaster prevention measures are a local government decision,

When “extraordinary” commentary is announced, specific disaster prevention measures are left to the judgment of the local government.

Some local governments that were interviewed initially decided to restrict access to the area around the crater. However, due to consideration for tourism, there were places where regulations were canceled depending on the state of volcanic activity.

The person in charge of the local government said, “In spite of the fact that the eruption alert level has not risen, regulations are limited only by temporary commentary information. It is difficult and confusing to decide disaster prevention measures with the explanation information of "Temporary" ".

Associate professor Yasunori Tsuji of Yamanashi University, who is familiar with volcanic disaster prevention, said, “Unlike the eruption warning level, the provisional information is not determined in advance. Ignore the impact on tourism that is important to the local community. It is difficult for local governments to make regulatory decisions, and the country needs to consider including a review of the information. "