August 31 , 2025.

Japan , Shinmoedake :

FUKUOKA (Kyodo) — Mt. Shinmoe on the southwestern Japan main island of Kyushu erupted Thursday, spewing a plume of ash 5,500 meters above the crater, a local office of the Japan Meteorological Agency said.

The eruption at 4:53 a.m. sent volcanic material 5,000 meters above the volcano’s peak for the first time since July 3, according to the agency.
The agency maintained the level 3 alert on a scale of 5, calling on the public to refrain from approaching the crater in both Miyazaki and Kagoshima prefectures.

This photo taken from a fixed-point camera on Aug. 28, 2025, from Kirishima, Kagoshima Prefecture, shows a plume of smoke emerging from Mt. Shinmoe. (Kyodo)

Mt. Shinmoe, straddling the two prefectures and one of 50 constantly monitored active volcanoes in Japan, erupted on June 22 for the first time since June 2018.

Source : The Mainichi.

Photo :  via Alex Terry / FB.

Indonesia , Lewotobi Laki-laki :

An eruption of Mount Lewotobi Laki-laki occurred on Friday, August 29, 2025, at 11:38 PM WITA. The observed ash column was ± 1,200 m above the summit (± 2,784 m above sea level). The ash column was gray, moderate to thick in intensity, and oriented southwest and west. This eruption was recorded by seismograph with a maximum amplitude of 11 mm and a duration of 103 seconds.

VOLCANO OBSERVATORY NOTICE FOR AVIATION – VONA

Issued : August 29 , 20250
Volcano : Lewotobi Laki-laki (264180)
Current Aviation Colour Code : ORANGE
Previous Aviation Colour Code : orange
Source : Lewotobi Laki-laki Volcano Observatory
Notice Number : 2025LWK404
Volcano Location : S 08 deg 32 min 20 sec E 122 deg 46 min 06 sec
Area : East Nusa Tenggara, Indonesia
Summit Elevation : 5069 FT (1584 M)

Volcanic Activity Summary :
Eruption with volcanic ash cloud at 15h38 UTC (23h38 local).

Volcanic Cloud Height :
Best estimate of ash-cloud top is around 8909 FT (2784 M) above sea level or 3840 FT (1200 M) above summit. May be higher than what can be observed clearly. Source of height data: ground observer.

Other Volcanic Cloud Information :
Ash cloud moving from southwest to west. Volcanic ash is observed to be gray. The intensity of volcanic ash is observed from medium to thick.

Remarks :
Eruption recorded on seismogram with maximum amplitude 11 mm and maximum duration 103 second.

Source et photo : Magma Indonésie .

Ecuador , Sangay :

DAILY STATUS REPORT OF SANGAY VOLCANO, Saturday, August 30, 2025.
Information Geophysical Institute – EPN.

Surface Activity Level: Moderate, Surface Trend: No change
Internal Activity Level: Moderate, Internal Trend: No change

Seismicity: From August 29, 2025, 11:00 a.m. to August 30, 2025, 11:00 a.m.:

Seismicity:
Below is the count of seismic events recorded at the reference station.
Explosion (EXP): 56

Precipitation/Lahars:
No rainfall has been recorded in the volcanic area. **Heavy rainfall could remobilize accumulated material, generating mud and debris flows that would cascade down the volcano’s flanks and flow into adjacent rivers.**

Emissions/Ash Column:
Since yesterday afternoon, several gas and ash emissions have been observed by surveillance cameras at heights between 100 and 600 meters above the crater, in a southwesterly direction. In this regard, the Washington VAAC has issued three emission reports, reaching heights of up to 600 meters above the crater, in a southwesterly direction.

Other monitoring parameters:
The FIRMS satellite system recorded 20 thermal anomalies, and the MIROVA-VIIRS satellite system recorded one thermal anomaly over the past 24 hours.

Observation:
Thanks to the surveillance camera system, the volcano was observed to be partially clear most of the time. At the time of writing, the volcano is cloudy.

Alert Level: Yellow

Source : IGEPN

Photo : Volcan Sangay / FB.

Hawaii , Kilauea :

Saturday, August 30, 2025, 8:30 AM HST (Saturday, August 30, 2025, 18:30 UTC)

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary:
The ongoing Halemaʻumaʻu eruption is paused. Eruptive episode 31 ended abruptly at 2:52 a.m. HST on August 23 after over 12 hours of continuous lava fountaining. Early this morning, minor glow was intermittently visible at the northern eruptive vent. Summit reinflation is underway at this time, and forecasting models suggest the likely window for episode 32 begins late this upcoming week. Episode 32 may occur even later if there are unexpected slowdowns in the summit inflation rate.

Summit Observations:
Minor glow was intermittently visible in webcam views of the Halemaʻumaʻu north vent early this morning. The lack of stronger glow—as observed shortly before previous eruptive episodes—suggests that active lava remains deep within the vent at this time.

“During a Kīlauea summit monitoring overflight on August 25, 2025, USGS Hawaiian Volcano Observatory field crews documented the geometry of the north vent that fountained predominantly during episode 31. The conduit is at a high angle into the southwest wall of the north vent.”

The Uēkahuna tiltmeter (UWD) recorded about 22 microradians of deflationary tilt during episode 31, and the end of the episode on Saturday, August 23 coincided with a rapid change from deflation to inflation at the summit. Since then, UWD has recorded approximately 15.5 microradians of inflationary tilt in total. The end of the episode also saw a decrease in seismic tremor intensity; presently, cyclic patterns of less intense seismic tremor indicate that gas pistoning is continuing deep within the eruptive vents, marked by low-frequency bursts around every 10 minutes.

Elevated degassing continues from the eruptive vents. Average sulfur dioxide (SO2) emission rates during inter-episode pauses are typically 1,200 to 1,500 tonnes/day, though emission rates vary on short timescales in association with gas pistoning.

Source : HVO.

Photo : USGS / K. Lynn

Costa Rica , Poas :

OVSICORI-UNA Weekly Volcano Monitoring Bulletin, August 29, 2025.

Latitude: 10.20°N;
Longitude: 84.23°W;
Altitude: 2,687 m.

Current Activity Level: Alert

No eruptions were recorded this week.
The seismic tremor amplitude remained low last week. It occasionally became harmonic with a frequency of approximately 3 Hz. The banded tremor observed since August 18 ceased on the 24th at 4:40 PM. A continuous acoustic tremor of moderate amplitude was also recorded. Three short episodes (approximately ten minutes long) of intensified acoustic tremor occurred on August 26 at 6:39 AM and on the 28th at 11:44 AM and 12:00 PM. No proximal volcano-tectonic (VT) events were recorded, and only one distal VT was recorded on August 25. The number of long-period events remains similar to that of the previous week.

In recent weeks, no significant deformation of the volcano has been detected.

MultiGAS stations measured an average SO2/CO2 ratio of 1.5 ± 0.4 this week, identical to last week. The H2S/SO2 ratio has remained very low (< 0.1) in recent weeks. Based on observed ratios, the gases are interpreted to be originating from a surface magmatic source. DOAS stations measured an SO2 flux of 360 ± 52 t/d.
In addition, satellite measurements of atmospheric SO2 indicate a maximum of 335 tons on August 27.

The level of the new hyperacid lake at Boca C remained relatively stable throughout August, with a slight increase. Given the persistence of high gas and heat flux at Boca A, as well as recent phreatomagmatic activity, a large and sudden eruption cannot be ruled out, even in the absence of warning signs, and could affect visited areas of the national park (e.g., ballistic projections towards the Mirador). Level 2 (Caution) does not rule out ballistic events in visited areas. Each phase of activity carries a potential risk.

Source et photo : Ovsicori .