Activity status of active volcanoes nationwide in April Announced by the Japan Meteorological Agency 0:18 on May 14
The Japan Meteorological Agency announced on April 13 the activity status and precautions for active volcanoes throughout Japan in April. It is announced that an eruption has occurred or volcanic activity is increasing. ▽ "Crater warning" is announced for 9 volcanoes nationwide ▽ "Eruption warning (surrounding sea)" is announced for one submarine volcano.
9 volcanoes around the crater
"Around the crater warning" has been announced because there is a possibility that future eruptions may affect the vicinity of the crater and the neighborhood of the residential area
▽ "Shirane Mountain" of Kusatsu Shirane Mountain in Gunma Prefecture ▽ "
Kumamoto Prefecture" "Mt. Aso"
▽ "Shinmoedake" of the Kirishima Mountains on the border of Kagoshima and Miyazaki
▽ "Sakurajima" "Kuchinoerabujima" "Satsuma Iwojima" "Suwanosejima"
▽ "Nishinoshima" of the Ogasawara Islands There are 9 volcanoes, including "Iwo Jima".
Eruption alert level 3 is 2 volcanoes
Of these, eruption alert level 3 indicating "entry restrictions" has been announced on "Sakurajima" and "Kuchinoerabujima" because there is a possibility that the area near the residence will be affected.
Kuchinoerabujima has had occasional eruptions since April 5th. Volcanic earthquakes and volcanic gas emissions continue to be high.
After April 11, it is sometimes observed that the hot volcanic gas appears red in clouds and fumes at night.
Since January, crustal movements showing bulging of the mountains have been observed, and it seems that magma underground is accumulating.
For this reason, the Japan Meteorological Agency has the possibility that an explosive eruption may lead to volcanic activity comparable to that in 2015 when all the residents were temporarily evacuated outside the island.
The Japan Meteorological Agency continues to call eruption warning level 3 for large volcanic blocks and pyroclastic flows within a range of approximately 2 km from the crater ▽ I will.
Eruption continues at Sakurajima's Minamidake summit crater. In April, 51 eruptions were observed, 14 of which were explosive eruptions, both increased from the previous month.
The volcanic plume rose up to 3800 meters from the crater, and large volcanic blocks reached the 4th station from 1300 to 1700 meters from the crater.
Observations on Sakurajima Island indicate that crustal movements, which are thought to indicate mountain bulges, have stagnated.
On the other hand, a wide range of satellite observations has shown that the long-term supply of magma under the Aira caldera in Kagoshima Bay has continued to accumulate, so it is possible that eruptions will continue to center around the Minamidake summit crater. There is.
The Meteorological Agency calls for caution against large volcanic blocks and pyroclastic flows within a range of approximately 2 kilometers from the Minamidake summit crater and the Showa crater.
Eruption alert level 2 is 5 volcanoes
The eruption alert level 2 where access to the crater area is restricted is
▽ "Shirane Mountain
" of Kusatsu Shirane
Mountain ▽ "Aso Mountain"
▽ " Shinmoedake" of "Kirishima Mountain Range" ▽ "Satsuma Iwo Jima"
▽ "Suwa Nose Island" It has been announced to the volcano.
At the Mt. Shirane of Kusatsu-Shirane, volcanic earthquakes increased slightly in the shallow part near Yugama from the beginning of September 2019, and the number suddenly increased to 30 times a day on April 30. Tilt fluctuations have also been observed, indicating expansion in shallow areas of the bath.
The Japan Meteorological Agency has called for warning of large volcanic rocks within a range of approximately 1 km from the Yugama crater, as there is a possibility that small-scale steam eruptions will continue to occur.
At Shinmoedake in the Kirishima Mountains, volcanic earthquakes are repeatedly increasing and decreasing. In April, it was 979 times, an increase from the previous month, and on April 21, it was 301 times a day. Volcanic earthquakes have exceeded 300 times a day since May 14, 2018 when the eruption occurred.
In addition, the amount of volcanic gas released is increasing, and volcanic activity is increasing. The Japan Meteorological Agency calls for large volcanic blocks approximately 2 kilometers from the crater, and pyroclastic flows approximately 1 kilometer.
Eruption continues at Mt. Aso at the Nakadake No. 1 crater. The amplitude of volcanic tremors has generally been small.
The amount of volcanic gas released per day is from 1000 tons to 2100 tons, a decrease from last month, but a little higher.
The Meteorological Agency cautions against large volcanic blocks and pyroclastic flows within a range of approximately 1 km from the Nakadake No. 1 crater, and urges local authorities not to enter dangerous areas.
An eruption occurred on April 29th at Satsuma Iwo Jima, with the highest plume rising up to 1000 meters from the crater. The eruption was confirmed since November 2, 2019.
After that, no eruption occurred, but at night, a high-temperature volcanic gas, etc. was observed in the clouds and fumes, and a reddish fire was observed. The condition continues.
The Japan Meteorological Agency has called for warning of large volcanic blocks, roughly 1 km from the crater.
Active eruption activity continues at the Mitake crater on Suwa Nose Island. From April 28th to April 29th, volcanic tremors with large amplitude intermittently accompanied by aerodynamic vibration occurred, and many explosive eruptions occurred.
Volcanic plumes rose up to 1600 meters from the crater, with large volcanic blocks reaching 800 meters from the crater.
The number of explosive eruptions in April was 118, a sharp increase from the previous month's two.
The Japan Meteorological Agency continues to call attention to large volcanic blocks within a range of approximately 1 km from the crater, as there is a risk of eruption affecting the area around the crater.
2 volcanoes without level warning
Although the eruption warning level has not been introduced, the "crater area warning" has been announced for "Nishinoshima" and "Iwojima" in the Ogasawara Islands.
Eruptions have been confirmed intermittently in Nishinoshima. Observations carried out by the Japan Coast Guard from the sky in April confirmed that the volcanic plume had risen to 1500 meters and lava was flowing from the pyroclastic cone to the east and south sides.
The Japan Meteorological Agency has continued to warn around the crater indicating that there is a risk of eruption, and has warned of large volcanic blocks and lava flows within a range of approximately 2.5 km from the summit crater.
On Iwo Jima, which is presumed to have undergone a seafloor eruption in September 2018, volcanic activity has remained rather active, with fluctuations indicating the uplift of the ground, and the temperature of the entire island becoming high. ..
The Japan Meteorological Agency has called for caution as there is a risk of an eruption affecting the crater area.
"Eruption warning (surrounding sea area)" in "Fukutokuoka Noba"
At "Fukutoku Okanoba", an undersea volcano near the Ogasawara Islands, an "eruption warning (surrounding sea area)" has been announced as a possible eruption affecting the surrounding sea area.
It is slightly active in the surrounding area, with discoloration of the sea surface, which is thought to be due to volcanic activity.
The Japan Meteorological Agency has called for caution in the surrounding waters, as a small-scale seabed eruption is expected.
No warning ・ Level 1 is risk recognition
In addition, eruption warnings have not been announced among the active volcanoes nationwide, and there are volcanoes with an eruption alert level of 1. However, it is still an active volcano that has repeatedly erupted in the past.
In February, volcanic activity is changing even at level 1, such as a sudden surge in volcanic earthquakes at Tokachidake in Hokkaido.
In August 2019, eruption occurred at level 1 on Mount Asama, and the level has been raised immediately after.
It should be re-recognized that sudden eruptions can occur in the absence of noticeable signs, even at the lowest eruption alert level 1.
Check the latest volcano information
You can check the activity status and cautions of volcanoes in each region on the website of the Meteorological Agency, local weather stations, and local governments.