Due to the eruption of a submarine volcano in the Ogasawara Islands, a large amount of pumice stones have been floating around the main island of Okinawa for 25 days.



More than 200 mackerel companions were found dead in the cage of a fishing port in the north.

The local fishermen's cooperative attributed the fish to swallowing pumice stones by mistake for food.



(The video is 37 seconds. It is a state of each place where pumice stones have arrived. You can not see it on data broadcasting).

Massive death of live fish due to pumice stones

On the morning of the 25th, the Kunigami Fisheries Cooperative confirmed that the fish were dead and floating in the cage set up just off the Hentona fishing port in Kunigami Village, Okinawa Prefecture.



The fish are a group of mackerels called "Gurukuma", which are about 40 cm in length, and about 200 of the 300 fish that were raised alive before they were shipped to Tokyo were dead.



At the fishing port, pumice stones from the eruption that occurred in August at Fukutoku-Okanoba, a submarine volcano in the Ogasawara Islands, were washed ashore and had entered the living space.

A fine pumice stone was found in the body of the fish, and the union attributed it to the fish swallowing the pumice stone by mistake for food.



Yoshihisa Murata, the head of the Kunigami Fisheries Cooperative, said, "Because of the pumice stones that are rushing to the fishing port, we have already been unable to go fishing for about a week, and we are in a difficult situation, but we can no longer ship live fish. I'm worried about how long this situation will last. "

A large amount of pumice drifts around the main island of Okinawa, and some drift to the coast

When NHK interviewed by helicopter from the sky on the 25th, it was seen that a large amount of pumice stones drifted over a wide area around the main island of Okinawa, and some of them drifted to the shore.



Below are images of points 1-7 on the map.

1. Kunigami Village

It is a Hentona fishing port in Kunigami village.

A large amount of pumice stones flowed into the harbor, and when viewed from above, the sea surface was gray as if cement had been poured.

Just outside the fishing port, a large number of pumice stones surround the cage, some of which are embedded in the cage.

There were also cages with multiple floating fish.

On the slope of the fishing port where the fishing boats were landed, the work of removing the accumulated pumice stones with heavy machinery continued.

2. Ogimi Village

This is Ogimi Village.

The pumice stones were drifting in strips on the sea a little away from the coast, and some were drifting on the coast.

3. Nago City

It is off the coast of Nago City.

Pumice stones float over a wide area in multiple strips, completely covering some of the coast.

4. Nakijin Village Kouri Island

Off the coast of Kouri Island, Nakijin Village, a ship was sailing between floating pumice stones.

5. Motobu Town

A large amount of pumice stones were floating on the blue sea off the coast of Motobu Town.

A large number of pumice stones were also launched on the coast.

6. Uruma City Ikei Island

It is Ikei Island, Uruma City, on the east side of the main island of Okinawa.

Pumice stones were lined up in a row on the coast.

7. Miyagi Island, Uruma City

It also arrived at the beach of Miyagi Island.

To consider the processing method to advance the understanding of the prefecture situation

Okinawa Prefecture is working to understand the situation of a large amount of pumice stones washed ashore at fishing ports and coasts by dispatching staff to the site.



In addition, regarding the disposal method, we will ask the national government if we can use the national subsidy system that can be used when disposing of garbage that has drifted to the coast, and we will also consider it in cooperation with the municipalities.

Pumice erupted in a submarine volcanic eruption in the Ogasawara Islands

Pumice stones were erupted in the eruption that occurred in August at Fukutoku-Okanoba, a submarine volcano in the Ogasawara Islands.

A group of experts announced the research result that it was the largest volcanic eruption in Japan since the Meiji era, based on the analysis of the amount of magma erupted.

Experts point out that it may continue.



Fukutoku-Okanoba, a submarine volcano south of Iwo Jima in the Ogasawara Islands, experienced a large-scale eruption on August 13, creating two islands due to a large amount of ejecta.



Research groups such as the Industrial Technology Research Institute analyzed the eruption scale based on observations from the meteorological satellite "Himawari" and father islands about 300 km away, and found that the height of the eruption was 16,000 meters to 10,000 meters. It reaches 9000 meters and the amount of magma eruption is estimated to be about 300 million to 1 billion tons.



For this reason, the research group said that the scale of this eruption was the second largest volcanic eruption in Japan since the Meiji era, following the "Taisho eruption" that occurred in Sakurajima in 1914 (Taisho 3). is.



A large amount of pumice stones generated by the eruption moved to the west due to the influence of ocean currents, and after the beginning of October, about two months after the eruption, they were washed ashore one after another in the Amami region of Okinawa and Kagoshima prefectures, and were used for ship navigation. I'm having trouble.

Will it be in Shikoku or Honshu next month?

Expert simulation

How will this pumice stone spread in the future?



JAMSTEC = Senior Researcher Toru Miyama of Japan Agency for Marine-Earth Science and Technology simulated how pumice stones ejected from Fukutoku-Okanoba drift based on the prediction of ocean currents near the sea surface such as the Kuroshio Current.

After the large-scale eruption in August, the pumice stones that arrived in Okinawa and Amami are expected to turn clockwise and proceed to the offshore area near Shikoku until early November.

After that, the pumice stones will continue to flow on the Kuroshio Current, and are expected to reach the offshore of the Kii Suido between Shikoku and the Kii Peninsula in mid-November.

It is expected that some pumice stones will meander in the south of Japan toward the end of November, and then move north again off the coast of Tokaido to approach the southern coast of Honshu, such as the Kanto region.



Toru Miyama, Senior Researcher of Japan Agency for Marine-Earth Science and Technology, said, "There is a possibility that pumice will meander greatly due to the influence of the Kuroshio Current and flow to the Tokai and Izu Islands. Please note that pumice will continue to drift for a while. ".

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