Asosan volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 23 July-29 July 2025 (Continuing Activity)
Wednesday, Jul 30, 2025 | 4 months ago · VN
The Japan Meteorological Agency (JMA) reported that unrest at Asosan had decreased. The amplitude of volcanic tremors had increased during 4-7 July but then returned to low levels afterward. During fi…Open article
Asosan volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 23 July-29 July 2025 (Continuing Activity)
Thursday, Jul 24, 2025 | 4 months ago · VN
The Japan Meteorological Agency (JMA) reported that unrest at Asosan had decreased. The amplitude of volcanic tremors had increased during 4-7 July but then returned to low levels afterward. During fi…Open article
Show more
Asosan volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 2 July-8 July 2025 (Continuing Activity)
Wednesday, Jul 9, 2025 | 4 months ago · VN
The Japan Meteorological Agency (JMA) reported that the amplitude of volcanic tremors at Asosan began to increase at around 1150 on 4 July, signaling an increasing unrest. Sulfur dioxide gas emissions…Open article
Asosan volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 2 July-8 July 2025 (Continuing Activity)
Thursday, Jul 3, 2025 | 5 months ago · VN
The Japan Meteorological Agency (JMA) reported that the amplitude of volcanic tremors at Asosan began to increase at around 1150 on 4 July, signaling an increasing unrest. Sulfur dioxide gas emissions…Open article
Asosan volcano - Smithsonian / USGS Weekly Volcanic Activity Report for 15 May-21 May 2024 (New Activity / Unrest)
Thursday, May 23, 2024 | 1 year ago · VN
JMA reported continuing unrest at Asosan. Sulfur dioxide gas emissions were somewhat high, averaging 1,600 tons per day (t/d), when measured during a field survey on 9 May. The amplitude of volcanic t…JMA reported continuing unrest at Asosan. Sulfur dioxide gas emissions were somewhat high, averaging 1,600 tons per day (t/d), when measured during a field survey on 9 May. The amplitude of volcanic tremors began to increase at around 0600 on 15 May and increased again round 0900.
At 0920 the Alert Level was raised to 2 (on a scale of 1-5) and the public was warned to stay at least 1 km away from t…Open article
At 0920 the Alert Level was raised to 2 (on a scale of 1-5) and the public was warned to stay at least 1 km away from t…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 22 March-28 March 2023 (Continuing Activity)
Wednesday, Mar 29, 2023 | 2 years ago · VN
The amplitude of volcanic tremor signals at Asosan increased in December 2022, and then further intensified on 30 January, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) and warn the …The amplitude of volcanic tremor signals at Asosan increased in December 2022, and then further intensified on 30 January, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) and warn the public to stay at least 1 km away from the crater. The amplitude fluctuated at high levels for a few weeks, and then decreased on 19 February and again on 14 March. Daily sulfur dioxide emissions had …Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 25 January-31 January 2023 (New Activity / Unrest)
Wednesday, Feb 1, 2023 | 2 years ago · VN
JMA reported that the amplitude of volcanic tremor signals at Asosan increased at around 1200 on 30 January and then increased again around 1220 and remained high. At 1330 JMA raised the Alert Level t…Open article
Aso volcano (central Kyushu, Japan): volcanic-seismic unrest, alert status raised to Yellow
Tuesday, Jan 31, 2023 | 2 years ago · martin
The seismic network of the Japan Meteorological Agency (JMA) registered periods of highly increased amplitude tremor at the volcano starting at noon yesterday.
At about 12:20 PM local time, a one-minut…The seismic network of the Japan Meteorological Agency (JMA) registered periods of highly increased amplitude tremor at the volcano starting at noon yesterday.
At about 12:20 PM local time, a one-minute seismic signal with an amplitude of 2.5 micrometers has been detected in a N-S pattern located on the western flank of the volcano. Later on, after 03:00 PM local time, the 2.5 micrometers amplitude…Open article
At about 12:20 PM local time, a one-minut…The seismic network of the Japan Meteorological Agency (JMA) registered periods of highly increased amplitude tremor at the volcano starting at noon yesterday.
At about 12:20 PM local time, a one-minute seismic signal with an amplitude of 2.5 micrometers has been detected in a N-S pattern located on the western flank of the volcano. Later on, after 03:00 PM local time, the 2.5 micrometers amplitude…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 13 April-19 April 2022 (Continuing Activity)
Wednesday, Apr 20, 2022 | 3 years ago · VN
JMA reported that no eruptions had been recorded at Asosan after the end of the last eruption in October 2021. Crater incandescence, which had been occasionally visible since December 2021, was absent…JMA reported that no eruptions had been recorded at Asosan after the end of the last eruption in October 2021. Crater incandescence, which had been occasionally visible since December 2021, was absent beginning on 27 February. Deflation began around 27 February but stabilized in April.
Observations of the crater from 17 March revealed that it had deepened, compared to pre-eruption conditions, and t…Open article
Observations of the crater from 17 March revealed that it had deepened, compared to pre-eruption conditions, and t…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 9 March-15 March 2022 (New Activity / Unrest)
Thursday, Mar 17, 2022 | 3 years ago · VN
JMA reported that the amplitude of volcanic tremor signals at Asosan had decreased at around 1540 on 27 February and remained low. White plumes rose 600-800 m above the crater during 7-14 March. Durin…JMA reported that the amplitude of volcanic tremor signals at Asosan had decreased at around 1540 on 27 February and remained low. White plumes rose 600-800 m above the crater during 7-14 March. During field surveys conducted on 8 and 10 March sulfur dioxide gas emissions were 1,300 and 900 tons per day, respectively; these values were higher than those measured before the October 2021 eruption.
No…Open article
No…Open article
Show more
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 23 February-1 March 2022 (New Activity / Unrest)
Thursday, Mar 3, 2022 | 3 years ago · VN
JMA reported that the amplitude of volcanic tremor signals at Asosan increased at around 0500 on 24 February and then increased again around 0900. About 45 minutes later JMA raised the Alert Level to …Open article
Aso volcano (Kyushu Isl., Japan): dense gas and steam plumes today, Volcanic Alert Level raised to 3
Saturday, Feb 26, 2022 | 3 years ago · martin
The Japan Meteorological Agency (JMA) reported about strong-gas steam plume at the volcano at 10:00 local time today.
Emissions of water vapor and gases were seen rising from the crater to estimated 7…Open article
Emissions of water vapor and gases were seen rising from the crater to estimated 7…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 17 November-23 November 2021 (New Activity / Unrest)
Wednesday, Nov 17, 2021 | 4 years ago · VN
JMA lowered the Alert Level for Asosan to 2 (on a scale of 1-5) at 1100 on 18 November and decreased the restricted area to a radius of 1 km, noting that no eruptions had been recorded since the 21 Oc…Open article
Aso volcano (Kyushu Isl., Japan): sudden large explosion this morning
Wednesday, Oct 20, 2021 | 4 years ago · T
A strong explosion occurred this morning, at around 11:43 local time, from the volcano.
During a phase of intense steam emissions, suddenly an explosion occurs that sends a large column of ash to sever…A strong explosion occurred this morning, at around 11:43 local time, from the volcano.
During a phase of intense steam emissions, suddenly an explosion occurs that sends a large column of ash to several kilometers height as well as a dense, ground-hugging circular base surge that almost reaches the visitors' center. On the following embedded video, large ballistic projectiles can be seen ejected f…Open article
During a phase of intense steam emissions, suddenly an explosion occurs that sends a large column of ash to sever…A strong explosion occurred this morning, at around 11:43 local time, from the volcano.
During a phase of intense steam emissions, suddenly an explosion occurs that sends a large column of ash to several kilometers height as well as a dense, ground-hugging circular base surge that almost reaches the visitors' center. On the following embedded video, large ballistic projectiles can be seen ejected f…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 20 October-26 October 2021 (New Activity / Unrest)
Wednesday, Oct 20, 2021 | 4 years ago · VN
JMA characterized the eruption at Asosan that occurred at 1143 on 20 October as medium-sized. The event ejected blocks 900 m S, produced pyroclastic flows that descended 1.3 km W, and generated an ash…Open article
Aso Volcano Volcanic Ash Advisory: ERUPTED AT 20211020/0243Z VA CLD UNKNOWN OBS VA DTG: 20/0230Z
Wednesday, Oct 20, 2021 | 4 years ago · VN
Volcanic Ash Advisory Center Tokyo (VAAC) issued the following report:
FVFE01 at 02:47 UTC, 20/10/21 …Open article
FVFE01 at 02:47 UTC, 20/10/21 …Open article
Aso Volcano Volcanic Ash Advisory: ERUPTED AT 20211015/0157Z FL050 STNR OBS VA DTG: 15/0200Z
Friday, Oct 15, 2021 | 4 years ago · VN
Volcanic Ash Advisory Center Tokyo (VAAC) issued the following report:
FVFE01 at 02:22 UTC, 15/10/21 from RJTD
VA ADVISORY
DTG: 20211015/0222Z
VAAC: TOKYO
VOLCANO: ASOSAN 282110
PSN: N3253 E13106
AREA: JAPAN…Open article
FVFE01 at 02:22 UTC, 15/10/21 from RJTD
VA ADVISORY
DTG: 20211015/0222Z
VAAC: TOKYO
VOLCANO: ASOSAN 282110
PSN: N3253 E13106
AREA: JAPAN…Open article
Aso volcano (central Kyushu, Japan): new eruption today
Thursday, Oct 14, 2021 | 4 years ago · martin
A new explosion occurred at the volcano from its Nakadake crater at 04:43 local time this morning as published the Japan Meteorological Agency (JMA).
A gas-steam plume containing some amount of ash rose 1,900 ft (600 m) above the crater.
The event was preceded by a gradually rising of volcanic tremo…A new explosion occurred at the volcano from its Nakadake crater at 04:43 local time this morning as published the Japan Meteorological Agency (JMA).
A gas-steam plume containing some amount of ash rose 1,900 ft (600 m) above the crater.
The event was preceded by a gradually rising of volcanic tremor starting from 15:30 local time yesterday, a sharp peak in tremor was reached during the eruption and later decreased again to medium-low values.
Judging from the webcam imagery, it appears as it was likely the phreatic or hydrothermal explosion, although this detail has yet to be confirmed by the volcano observatory. Phreatic explosions occur when steam-rich blasts of old rock are formed without…Open article
A gas-steam plume containing some amount of ash rose 1,900 ft (600 m) above the crater.
The event was preceded by a gradually rising of volcanic tremo…A new explosion occurred at the volcano from its Nakadake crater at 04:43 local time this morning as published the Japan Meteorological Agency (JMA).
A gas-steam plume containing some amount of ash rose 1,900 ft (600 m) above the crater.
The event was preceded by a gradually rising of volcanic tremor starting from 15:30 local time yesterday, a sharp peak in tremor was reached during the eruption and later decreased again to medium-low values.
Judging from the webcam imagery, it appears as it was likely the phreatic or hydrothermal explosion, although this detail has yet to be confirmed by the volcano observatory. Phreatic explosions occur when steam-rich blasts of old rock are formed without…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 13 October-19 October 2021 (New Activity / Unrest)
Wednesday, Oct 13, 2021 | 4 years ago · VN
According to JMA the number of volcanic tremor signals at Asosan began on 12 October. Tremor amplitude began increasing at 1530 on 13 October, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) almost two hours later. White plumes rose 1.4 km above Nakadake Crater.
An eruption was detect…According to JMA the number of volcanic tremor signals at Asosan began on 12 October. Tremor amplitude began increasing at 1530 on 13 October, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) almost two hours later. White plumes rose 1.4 km above Nakadake Crater.
An eruption was detected at 0443 on 14 October; weather clouds prevented visual confirmation of an eruption plume, though ejected incandescent material was visible in thermal camera images. During a field visit to the volcano later that day, scientists confirmed ashfall in several areas, including parts of Takamori Town (Kumamoto Prefecture), Taketa City (Oita Prefecture), and Takachiho Town (Miyazaki Prefecture). Smal…Open article
An eruption was detect…According to JMA the number of volcanic tremor signals at Asosan began on 12 October. Tremor amplitude began increasing at 1530 on 13 October, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) almost two hours later. White plumes rose 1.4 km above Nakadake Crater.
An eruption was detected at 0443 on 14 October; weather clouds prevented visual confirmation of an eruption plume, though ejected incandescent material was visible in thermal camera images. During a field visit to the volcano later that day, scientists confirmed ashfall in several areas, including parts of Takamori Town (Kumamoto Prefecture), Taketa City (Oita Prefecture), and Takachiho Town (Miyazaki Prefecture). Smal…Open article
Asosan volcano (Kyushu, Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 9 June-15 June 2021 (Continuing Activity)
Wednesday, Jun 9, 2021 | 4 years ago · VN
Volcanic tremor amplitude had increased at Asoson on 2 May, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5). The amplitude remained high through 10 May, and then gradually decreased. On 9 June the Alert Level was lowered to 1 and the public was warned of an increased risk within 1 km…Open article
