The Japan Meteorological Agency announced the activity status of active volcanoes nationwide in March and points to watch out for.
"Crater area warning" has been announced for seven volcanoes nationwide, and "eruption warning (peripheral sea area)" has been announced for one submarine volcano, saying that eruptions are occurring and volcanic activity is increasing.
7 volcanoes around the crater
The "crater area warning" has been announced because the eruption may affect the area around the crater and the area where you live.
▽ "Mt. Asama" on the prefectural border between Nagano and Gunma prefectures
▽ "Sakurajima" in Kagoshima prefecture "Kuchinoerabu Island" "Sakura Iojima" "Suwanosejima"
are 7 volcanoes in total
, "Nishinoshima" and "Iojima" in the Ogasawara Islands
Volcanic Alert Level 3 is 2 volcanoes
Of these, eruption alert level 3, which indicates "mountain entry restrictions" that may affect the vicinity of the place of residence, has been announced on "Sakurajima" and "Kuchinoerabujima".
Eruptive activity continued at the Minamidake summit crater of Sakurajima, and large volcanic blocks reached the 4th station from 1300 meters to 1700 meters from the crater, and the eruption smoke rose to 3200 meters from the crater at the maximum.
In addition, the eruptive activity is thought to continue because the magma supplied for a long period of time continues to accumulate beneath the Aira Caldera in Kagoshima Bay and the amount of volcanic gas released continues to be high. ..
The Japan Meteorological Agency calls for caution against large volcanic bombs and pyroclastic flows within a range of approximately 2 km from the Minamidake summit crater and Showa crater.
On February 21, there have been many volcanic earthquakes with epicenters in shallow areas near the crater of Shindake, but the number gradually decreases as the number increases and decreases. doing.
The Japan Meteorological Agency warns against large volcanic bombs and pyroclastic flows within a range of approximately 2 km from the crater, and warns against pyroclastic flows from the crater to the southwest of Shindake from the Mukaihama area to the coast.
Volcanic Alert Level 2 is 3 volcanoes
Eruption alert level 2 that restricts access to the crater area has been announced at three volcanoes: ▽ "Mt. Asama" ▽ "Satsuma Iojima" ▽ "Suwanosejima".
the Ontake crater on Suwanosejima, active eruptive activity continued, and explosions increased temporarily. From March 30 to 31, large volcanic stones continued to reach nearly 1 km from the crater. The eruption alert level was raised to 3 as it was confirmed that it flew in.
Since then, the number of explosions has decreased, and since April 1, no eruption has been observed that causes a large volcanic bomb to fly close to 1 km from the crater, so the eruption alert level was lowered to 2 on the 5th.
The Japan Meteorological Agency is calling for caution against large volcanic bombs within a range of approximately 1 km from the crater.
Mt. Asama, slight tilt fluctuations that are thought to indicate expansion have been confirmed on the west side of the mountain from around March 15.
Since the 20th, the number of volcanic earthquakes with epicenters in shallow mountains has increased.
The eruption alert level was raised to 2 on the 23rd due to increased volcanic activity and the possibility of small-scale eruptions affecting approximately 2 km from the summit crater in the future.
The Japan Meteorological Agency calls for caution against large volcanic bombs and pyroclastic flows within a range of approximately 2 km from the summit crater.
<Satsuma Iojima> On
Satsuma Iojima, there is no particular change in the occurrence of volcanic earthquakes and tremors, but in the long run, a "fire phenomenon" is observed at night and the eruption of smoke rises occasionally. The state of increased thermal activity continues.
The Japan Meteorological Agency is calling for caution against large volcanic bombs within a range of approximately 500 meters from the crater.
2 volcanoes with no level warning
Although the eruption alert level has not been introduced, the "crater area warning" has been announced for "Nishinoshima" and "Iwojima" in the Ogasawara Islands.
No eruptions have been observed on Nishinoshima since late August 2020.
Although volcanic activity is declining, there are fumaroles and high temperature areas inside the summit crater, and it is possible that eruptions will resume in the future.
The Japan Meteorological Agency has continued to warn around the crater, which indicates "danger of entering the mountain," and is calling for caution against large volcanic bombs and lava flows within a range of approximately 1.5 km from the summit crater.
On Iwo Jima, which is estimated to have had a seafloor eruption in September 2018, crustal movements indicating uplift of the entire island have been observed over the long term, and volcanic activity has remained somewhat active. ..
In addition, the ground temperature is high as a whole on the island, and there are many fumaroles, etc., and small-scale eruptions have occurred in the past.
The Japan Meteorological Agency may cause an eruption that affects the area around the crater, and is calling for caution in the surrounding waters.
"Eruption warning (surrounding sea area)" in "Fukutoku Okanoba"
At "Fukutoku Okanoba", a submarine volcano near the Ogasawara Islands, an "eruption warning (surrounding sea area)" has been announced as there is a risk of an eruption affecting the surrounding sea area.
According to the observations made by the Japan Coast Guard and others, discoloration that seems to be caused by volcanic activity has been confirmed on the surrounding sea surface for a long period of time.
The Japan Meteorological Agency is expected to have a small submarine eruption and is calling for caution against eruptions in the surrounding waters.
"Mt. Shirane" of Mt. Kusatsu-Shirane has been reduced to level 1.
At "Mt. Shirane" on Mt. Kusatsu-Shirane, volcanic earthquakes with epicenters near Yugama continue to occur, but seismic activity has been sluggish since late January.
In addition, observations with an inclinometer showed no obvious change that was thought to be due to expansion in the shallow part near the bathtub, and it has been generally stagnant since late February.
For this reason, the Japan Meteorological Agency said that volcanic activity tends to return to a calm state, and the possibility of an eruption affecting a range of about 1 km from the Yugama crater is low, so the eruption alert level was set to 1 on the 23rd. I lowered it.
The Japan Meteorological Agency is urging people to stay out of dangerous areas according to the instructions of the local government, as there is a possibility of a very small amount of volcanic ash erupting within a range of about 500 meters from the Yugama crater.
No alarm, level 1 also risk awareness
No eruption warning has been announced among active volcanoes nationwide, and there are volcanoes with an eruption alert level of 1, but they are still active volcanoes that have repeatedly erupted in the past.
At Tokachidake in Hokkaido, volcanic activity has changed even at level 1, such as the first fire projection since 2000 in June 2020 and volcanic tremors.
It is also necessary to recognize again that a sudden eruption can occur in the absence of any noticeable precursors.
Check the latest information
You can check the activity status and precautions of volcanoes in each area on the Japan Meteorological Agency, meteorological observatories in each area, and the websites of local governments.