AVO report
ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, February 7, 2025, 12:42 PM AKST (Friday, February 7, 2025, 21:42 UTC)
GREAT SITKIN (VNUM #311120)
52°4'35" N 176°6'39" W, Summit Elevation 5709 ft (1740 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Activity at Great Sitkin Volcano has remained unchanged over the past week, with lava continuing to erupt slowly in the summit crater. Intermittent, small volcanic earthquakes persist. A few clear views of the volcano in satellite and webcam images showed no activity of note.
Since the May 2021 explosion, there have been no other explosions at Great Sitkin Volcano. The lava eruption that began in July 2021 is ongoing. It has filled most of the summit crater and advanced into valleys below. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.
SPURR (VNUM #313040)
61°17'56" N 152°15'14" W, Summit Elevation 11070 ft (3374 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Volcanic unrest continues at Mount Spurr. Please see the Information Statement released yesterday for an overview, interpretations, and possible outcomes.
Over 200 earthquakes were located under Mount Spurr over the past week. Most of these small (less than magnitude 1) events were located beneath Crater Peak, the flank vent south of the summit that was the site of the 1953 and 1992 eruptions. Data from GNSS stations show that outward inflation (deformation) continues at about the same rate that has been occurring since spring of 2024. We continue to watch closely for surface changes that might suggest heating of the volcano. Thus far we see no obvious such changes at the Crater Peak vent. The ice-filled crater lake at the Spurr summit is still present but remains relatively unchanged over the past week.
The Spurr monitoring network continues to experience weather-related telemetry issues that began on January 20—22. AVO engineers have been making repairs this week, including a helicopter-supported trip today to dig out stations that are covered in snow and ice. Gas measurements are also planned for today.
AVO continues to closely monitor activity at Mount Spurr for signals that would indicate that the volcano is moving closer to an eruption using local seismic, infrasound, web camera, and GNSS stations along with regional infrasound, lightning networks and satellite data. Based on previous eruptions, additional changes in earthquakes, ground deformation, the summit lake, and fumaroles would be expected if magma begins to move closer to the surface. Therefore, it is very likely that if an eruption were to occur it would be preceded by additional signals that would allow advance warning.
CVO report
CASCADES VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, February 7, 2025, 12:49 PM PST (Friday, February 7, 2025, 20:49 UTC)
CASCADE RANGE (VNUM #)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Activity Update: All volcanoes in the Cascade Range of Oregon and Washington are at normal background activity levels. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State and Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake in Oregon.
Past Week Observations: During the past week, small earthquakes were detected at Mount Rainier, Mount St. Helens, and Mount Hood. All monitoring data are consistent with background activity levels in the Cascade Range. Field crews performed station maintenance at Newberry and Three Sisters.
CENAPRED report
Cenapred monitoring report
on the Popocatépetl volcano
February 8, 11:00 h (February 8, 17:00 GMT)
Activity in the last 24 hours:
107 exhalations were detected, accompanied by water vapor and volcanic gases (image 1) . Additionally, 94 minutes of high-frequency tremor and 129 minutes of harmonics, both of low amplitude, were recorded. Also, yesterday, 6 volcanotectonic earthquakes were recorded at 10:13, 10:14, 10:20, 12:29, 12:43 and 14:45 h, with magnitudes between 1.5 and 2.1.
During the morning and at the time of this report, a light emission of water vapor and volcanic gases is observed in a northeasterly direction
The Popocatépetl Volcanic Alert Traffic Light is in Yellow Phase 2.
HVO report
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, February 8, 2025, 9:21 AM HST (Saturday, February 8, 2025, 19:21 UTC)
KILAUEA (VNUM #332010)
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:
Kīlauea summit eruption paused as of February 4. A new eruptive episode may begin within the next 4 days in Hawai'i Volcanoes National Park.
Episode 8 of the ongoing Halemaʻumaʻu eruption ended abruptly at 7:23 p.m. HST on February 4 after about 21.5 hours of eruptive activity. Kīlauea's current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024. There have been 8 episodes of lava fountaining separated by pauses in activity. All eruptive activity remains within Hawai'i Volcanoes National Park. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.
Current hazards include volcanic gas emissions and windblown volcanic glass (Pele’s Hair) that may impact Hawai’i Volcanoes National Park and nearby communities.
Summit Observations:
Lava flows and fountains stopped erupting from the north vent within Halemaʻumaʻu crater at about 7:07 p.m. HST on February 4, followed by the south vent at 7:23 p.m. HST. Lava flows from episode 8 covered greater than half of the Halemaʻumaʻu crater floor. A few spots of weak orange glow can still be seen on the crater floor at night as the erupted lava continues to cool. The north vent continues to degas and glow at night, indicating magma remains at shallow levels in the vent.
Summit tilt changed rapidly from deflation to inflation, and seismic tremor decreased, at about the same time that the lava fountains stopped erupting on February 4. The Uēkahuna (UWD) and Sand Hill (SDH) tiltmeters have both recorded approximately 5 microradians of inflationary tilt since the end of episode 8. Seismic tremor decreased significantly at the end of episode 8 but remains above background. No earthquakes were recorded in the summit region over the past 24 hours.
Volcanic gas emissions remain elevated. Based on measurements made during earlier episodes and pauses, sulfur dioxide (SO2) emission rates are likely to be approximately 1,000 t/d during the current pause. An SO2 emission rate of 1,200 t/d was measured on February 3.
Strands of volcanic glass known as Pele’s Hair have been reported on surfaces throughout the summit area of Hawai’i Volcanoes National Park and surrounding communities.
Summit eruption livestream: https://www.youtube.com/usgs/live
Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams
Rift Zone Observations:
Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone with no significant earthquake activity in the past 24 hours. Sulfur dioxide (SO2) emissions from the East Rift Zone remain below detection limit.
Analysis:
The current eruption is marked by episodic fountaining not seen in any of the other Halemaʻumaʻu eruptions since 2020. Fountains and lava flows have erupted from two vents that we refer to as the north vent and south vent. The 8 fountaining episodes lasted from a few hours to over a week. Each fountaining episode has been accompanied by strong deflation of the summit region. Pauses between the fountaining episodes have been marked by an immediate change from deflation to inflation as the magma chamber recharges and repressurizes.
Analysis of inflationary tilt patterns prior to the onset of each fountaining episode allows a time window of probability for the onset of new episodes to be estimated. These are calculated using both minimum inflation necessary to start a new eruption and the rate of inflation. Current inflation rates at UWD and SDH indicate that the most likely window of time for a new episode to begin is between Saturday evening or Sunday morning and Wednesday, February 12. This estimate was revised due to slowing of the inflation rate to less than 1 microradian per day Friday afternoon. If this lower rate continues, the most likely window of time for the next episode will be extended.
Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
Summit eruption reference map: January 15, 2025—Kīlauea summit eruption reference map | U.S. Geological Survey
Volcano Watch article about Pele's Hair from this eruption: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards
HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards.
NEWS
Volcano Watch - An assembly of volcano scientists to gather in Hilo
By Hawaiian Volcano Observatory
February 6, 2025
What is the collective noun for a group of volcano scientists? While some tongue-in-cheek responses might be “an eruption of volcanologists” or “a swarm of seismologists,” we’ll stick to “an assembly of volcano scientists.”
Next week, during February 9-14, volcano scientists from around the world are gathering in Hilo, united by the common goal of understanding caldera-forming eruptions at basaltic volcanoes.
The occasion for the assembly is the American Geophysical Union Chapman Conference on Caldera-forming Eruptions at Basaltic Volcanoes: Insights and Puzzles from Kīlauea 2018 and Beyond. The meeting is directly aligned with the U.S. Geological Survey’s Volcano Hazards Program mission—“to enhance public safety and minimize social and economic disruption from volcanic unrest and eruption.”
Read complete article here
INSIVUMEH report
Daily bulletin of volcanology
Updated by Wendel Alexander Gutiérrez Paxtor on
PACAYA VOLCANO (1402-11)
Type of activity: Strombolian. Morphology: Composite volcano stratum.
Geographic location: 14°22'50˝ N latitude; 90°36'00˝ W longitude. Height: 2,552 masl.
Weather conditions: partly cloudy Wind: North Rainfall: 0.0 mm
Activity : Weak degassing has been observed over the crater during periods of clearing. INSIVUMEH seismic stations continue to record short, low-frequency events, suggesting magma and gas activity inside the volcano, as well as prolonged or abundant periods of degassing in the crater.
FUEGO (1402-11)
Type of activity: Vulcanian. Morphology: Composite volcano stratum.
Geographic location: 14°28'54˝ N latitude; 90°52'54˝ W longitude. Height: 3,763 m above sea level.
Atmospheric conditions: Partly cloudy Wind: southeast Rainfall: 0.0 mm.
Activity: Weak white degassing (water vapor and other magmatic gases) is observed rising up to 300 meters above the crater. Accelerated winds at low altitude can stir up sediments which could generate a curtain of ash, which could cause ash fall in communities near the volcano. At night and early morning, slight incandescence was observed over the crater. No sounds or rumblings have been reported. The wind direction at heights above the crater is mainly west and northwest, and according to numerical models it will continue this way for the next 24 hours.
SANTIAGUITO VOLCANO (1402-03)
Type of activity: Pelean Morphology: Dacitic dome complex
Geographic location: 14 °44' 33˝ N Latitude; 91°34'13˝ W Longitude. Height: . 2,500 meters above sea level.
Atmospheric conditions: Clear Wind: from the west Rainfall: 0.0 mm.
Activity: Degassing is observed over the crater. Weak and moderate explosions are recorded, expelling columns of gas and ash that reach up to 900 meters in height over the crater and disperse to the southwest and west. At night and early in the morning, incandescence was observed in the crater of the Caliente dome and in the upper part of the lava flow in a west-southwest direction. Weak, moderate and some strong block avalanches are recorded on the lava flow, on the south flank and on the southeast flank. Due to the direction of the wind, fine ash fall is expected on farms near the southwest and west of the Caliente dome. The possibility of moderate to strong block and ash flows, as well as long-range pyroclastic flows in different directions, cannot be ruled out, therefore, one should not remain near or within the riverbeds near the slopes of the volcano.
KVERT report
KVERT DAILY REPORT
Kamchatkan and Kuriles Volcanic Activity
February 07, 2025, all time is UTC
SHEVELUCH VOLCANO (CAVW #300270)
56.64 N, 161.32 E; Elevation 3283 m (10768 ft), the dome elevation ~2500 m (8200 ft)
Aviation Colour Code is ORANGE
A growth of the lava dome of the Young Sheveluch volcano, and the 300 years of RAS (the Russian Academy of Sciences) lava dome on the southwestern slope of the Old Sheveluch volcano continues. A growth of the domes is accompanied by powerful gas-steam activity. Satellite data by KVERT showed thermal anomalies over the both lava domes.
BEZYMIANNY VOLCANO (CAVW #300250)
55.97 N, 160.6 E; Elevation 2882 m (9453 ft)
Aviation Colour Code is ORANGE
An effusive eruption of the volcano continues. Satellite data by KVERT showed a thermal anomaly over the volcano.
KARYMSKY VOLCANO (CAVW #300130)
54.05 N, 159.44 E; Elevation 1486 m (4874 ft)
Aviation Colour Code is ORANGE
A moderate activity of the volcano continues. Satellite data by KVERT showed the volcano was obscured by clouds.
MAGMA report
Ibu
Saturday - February 08, 2025, period 00:00-24:00 WIT
Created by, Rivaldi Hasan
Level III (Alert)
Visual Observation
The volcano is clearly visible until covered by Fog 0-III. Observed white main crater smoke with thin high intensity around 100-200 meters from the peak. The weather is sunny to cloudy, light to moderate winds to the east, southeast and south.
Earthquake Observation
43 times Eruption earthquakes with an amplitude of 13-28 mm, and an earthquake duration of 34-103 seconds.
1 avalanche earthquake with an amplitude of 3 mm and an earthquake duration of 41 seconds.
44 times Gust earthquake with amplitude 2-18 mm, and earthquake duration 14-68 seconds.
18 times Harmonic with amplitude 2-21 mm, and earthquake duration 35-119 seconds.
137 times Shallow Volcanic earthquakes with amplitude of 2-10 mm, and earthquake duration of 4-19 seconds.
5 times Deep Volcanic earthquakes with amplitude of 2-6 mm, SP 1.2-2 seconds and earthquake duration of 13-19 seconds.
1 local tectonic earthquake with an amplitude of 3 mm, SP 8.39 seconds and an earthquake duration of 31 seconds.
15 times Distant Tectonic earthquakes with amplitude of 2-28 mm, SP not observed and earthquake duration 37-200 seconds.
Lewotobi Laki-Laki
Saturday - February 08, 2025, period 00:00-24:00 WITA
Created by, Emanuel Rofinus Bere, A.Md.Kom.
Level III (Alert)
Visual Observation
The volcano is clearly visible until covered by Fog 0-II. Observed white main crater smoke with moderate to thick intensity about 50-200 meters high from the peak. The weather is sunny to rainy, weak winds to the north and northeast.
Earthquake Observation
27 times Gust earthquake with amplitude 2.9-29.6 mm, and earthquake duration 30-126 seconds.
1 time Harmonic with an amplitude of 5.9 mm, and an earthquake duration of 103 seconds.
1 Low Frequency earthquake with an amplitude of 22.2 mm, and an earthquake duration of 24 seconds.
1 distant tectonic earthquake with an amplitude of 7.4 mm, SP 13.1 seconds and an earthquake duration of 60 seconds.
Merapi,
Saturday - February 08, 2025, period 00:00-24:00 WIB
Created by, Erwin Widyon
Level III (Alert)
Visual Observation
The volcano is clearly visible until covered by Fog 0-III. Observed white smoke from the main crater with a high thick intensity of about 10-15 meters from the peak. The weather is sunny to cloudy, with weak winds to the east and west.
Other Information
Observed 3 times lava avalanches to the southwest (Kali Sat) with a maximum sliding distance of 1,500 meters.
Earthquake Observation
104 times Avalanche earthquakes with amplitude of 2-20 mm and earthquake duration of 47.79-14297 seconds.
32 times Hybrid/Multi-Phase earthquakes with amplitude of 2-9 mm, SP 0.2-0.7 seconds and earthquake duration of 7.45-13.69 seconds.
OVPF-IGPG report
NEWS
Press release Paris Institute of Globe Physics Piton de la Fournaise Volcanological Observatory 06/02/2025 - 10:30 p.m. local time 6:30 p.m. UTC
Earthquake felt On Thursday, February 6, 2025, 9:50 p.m. (local time, 5:50 p.m. UT), an earthquake was felt by residents of the island, mainly in the western sector of the island.
This earthquake was recorded by the seismometers of the Piton de la Fournaise Volcanological Observatory. The first analyzes of this earthquake made it possible to locate it, 5 km west-southwest of Cilaos, at a depth of 11 km (i.e. a hypocentral distance of approximately 12 km). Its magnitude was measured at 2.3 on the Richter scale.
OVPF staff are working to refine the location calculations for this event. Also the information concerning the location and the intensity could evolve marginally
This type of event, felt by the population, is recorded several times a year. This event is isolated and is of tectonic origin. To date, this earthquake has not been followed by aftershocks.
OVSM-IGPG
Weekly report Paris Institute of Globe Physics Martinique Volcanological and Seismological Observatory
Activity on Montagne Pelée Saint-Pierre,
February 7, 2025 at 3:00 p.m. local time (GMT-4)
Between January 31, 2025 at 4:00 p.m. (UT) and February 7, 2025 at 4:00 p.m. (UT), TOVSM did not record any earthquake of volcanic origin.
The previous week, the OVSM had not recorded any earthquake of volcanic origin. As of February 7, 2025 and during the last 4 weeks, the OVSM has therefore observed a total of 15 volcanic earthquakes, an average of 3 to 4 earthquakes per week.
During phases of volcanic reactivation of volcanoes similar to Montagne Pelée, it is usual to observe seismic activity varying in intensity and frequency. F
For more details on observations and interpretations of volcanic activity over the longer term, refer to the OVSM monthly bulletins. The alert level is currently YELLOW: vigilance
OVISCORI report
OVSICORI-UNA Weekly Volcanic Watch Bulletin February 7, 2025
Poás Volcano
Lat : 10.20°N; Long: 84.23°W; Altitude: 2687 m.a.s.l.
Current level of activity: Warning
Possible manifestations: Small eruptions, gush or geyser, significant gas emission, temperature increase (incandescence), seismic swarms or volcanic tremor, slightly inflation-extension of the volcanic edifice
Between June 30 and February 4, a sequence of shallow proximal volcano-tectonic earthquakes (pVT) occurred. Few of these presented tonal coda. Few long-term events are detected. At the end of the pVT sequence, changes in the background tremor were observed, including an increase in its amplitude.
Geodetic monitoring has recorded one episode of inflation since November, with the most significant from late December to late January. In recent days, inflation seems to have stopped. The station north of the crater shows stability, while in the south a slight subsidence is observed. The update of the model indicates a source at a depth of 1-3 km under the crater and a change in volume of less than 1 Mm³.
For two weeks, a decrease in the flow of SO2 has been observed. During the past week the flow of this gas was 261 ± 52 t/d, while the value corresponding to the previous week was 321 ± 78 t/d. However, the flow of SO2 is still high. The MultiGAS station has recorded lower SO2 concentrations this week (weekly average of 5 ppm, compared to 13 ppm the previous week). The SO2/CO2 ratio remains relatively stable at an average of 1.0 ± 0.5 this week. The H2 S/SO2 ratio remains low with values close to 0. The concentrations of SO2 recorded at the Mirador have dropped this week, with a maximum of 1.5 ppm. The SENTINEL satellite's OMI instruments have not detected SO2 in the atmosphere since January 24. The lake level decreased by about 0.2 m in 1 week. The temperature of the lake was measured directly on February 3 (52°C) and the pH of the water was 0.35 (hyperacidic). The lake shows a slight decrease in the rate of evaporation across its surface but is still maintained with underwater fumarolic convection. It is relevant to mention that from mid-December 2024 to the present, a change in the conditions of the reduction-oxidation potential of the lake's waters (REDOX or ORP potential) is observed. The ORP of the lake has been declining from values around 360 mV to 298 mV, which indicates that the lake is receiving an injection of less oxidized fluids in recent days, and therefore, there is a decrease in the chemical activity of oxidation of the water.
Rincon de la Vieja Volcano
Lat: 10.83°N; Long: 85.34°W; Altitude: 1916 m.a.s.l.
Current level of activity: Warning
Possible manifestations: Small eruptions, gush or geyser, significant emission of gases, increase in temperature (incandescence), seismic swarms or volcanic tremor, slight inflation-extension of the volcanic edifice.
No rashes or exhalations were recorded this week. After several weeks of very low-energy tremor, episodes of short tremors were recorded, sometimes of a harmonious nature. After episodes of short tremors, the background tremor appears with a frequency range between 1 and 6.5 Hz. Long-period and screw-type signals also persist. The dominant frequency of screws shows a slight tendency to decrease in recent weeks. Volcano-tectonic earthquakes are recorded distal (northern flank of the volcano) and proximal to the crater. Geodetic observations show stability at the base and at the top. During the last week, the average flow of SO2 was 126 ± 24 t/d, lower than the previous week 286 ± 138 t/d. The SENTINEL satellite's OMI instruments have not detected SO2 in the atmosphere since December 26, 2024.
Turrialba Volcano
Lat: 10.02°N; Long: 83.76°W; Altitude: 3325 m.a.s.l.
Current level of activity: Warning
Possible manifestations: Small eruptions, significant emission of gases, increase in temperature (incandescence), seismic swarms or volcanic tremor, slight inflation-extension of the volcanic edifice.
There are no eruptions or volcanic tremor. The volcanic seismicity of Turrialba is characterized by few low-frequency and low-amplitude volcanic earthquakes of the LP type and tonal coda. In recent months, crustal contraction and subsidence centered on the eastern flank of the Irazú volcano and a more marked contraction and subsidence have been observed in the vicinity of the active crater of Turrialba. The MultiGAS station has recorded low concentrations of gases this week. During the previous week, an average SO2 flow of 214 ± 25 t/d was recorded, similar to that of the previous week (245 ± 32 t/d). The last detection of SO2 in the atmosphere by the Sentinel-5P satellite was on December 17, 2024.
Irazu Volcano
Lat: 9.98°N; Long: 83.85°W; Altitude: 3427 m.a.s.l.
Current level of activity: Calm
Possible manifestations: tectonic earthquakes, casual low-frequency earthquakes, hydrothermal activity (fumaroles, diffuse gases, hot springs, etc.).
The landslide in the Las Torres sector, after several months of stable subsidence, shows a reduction in its sinking rate. Diffuse degassing in the fumarolic field located on the northern flank remains normal with CO2 concentrations below 500 ppm and CO2/H2 S between 50 and 200.
Arenal Volcano
Lat: 10.46°N; Long: 84.70°W; Altitude: 1755 m.a.s.l.
Current level of activity: Calm
Possible manifestations: tectonic earthquakes, casual low-frequency earthquakes, hydrothermal activity (low-temperature fumaroles, diffuse gases, hot springs, etc.), rockslides.
Seismicity in the surroundings of the Arenal volcano remains generally low during the current year 2025. This week there have been five volcano-tectonic earthquakes proximal to the volcano.
PHIVOLCS report
MAYON VOLCANO
24-hour monitoring summary (from 12AM yesterday to 12AM today)
Date: 08 February 2025 (Partial activity)
ALERT LEVEL 1
Seismicity
1 volcanic earthquake + 3 Rockfall events
Crater glow
Weak (only visible through telescope)
Sulfur Dioxide Flux
204 ton / araw (05 February 2025)
Plume
Moderate evaporation; drifting west-southwest
Ground Deformation
Temporary volcanic eruption
RNVV-SERNAGEOMIN report
(The following is highlights from a verrry lengthy regional monthly report)
Volcanic Activity Report (RAV) N°2 January 2025 Los Ríos Region The National Geology and Mining Service (Sernageomin) of Chile releases the following information obtained through the monitoring equipment of the National Volcanic Surveillance Network (RNVV), processed and analyzed at the Volcanological Observatory of the Southern Andes (Ovdas):
A. Summary of volcanic alert According to the evaluation of the activity recorded during the indicated period, the technical alert for the volcanic systems of the region are as follows:
1. Villarrica Volcano
Period evaluated: January 1 to 31
Volcanic technical alert GREEN is maintained
Observation:
The monitoring of the surface and instrumental activity of the volcano indicates a decrease in the frequency of explosions with emission of high-temperature volcanic material outside the crater. As it is an open-conduit volcanic system, it is not possible to rule out sudden explosions without precursors. According to what has been observed in previous periods, the impact of these explosions is mostly concentrated at distances of less than 500 m, measured from the center of the crater. However, in the current scenario, the low surface activity together with the decrease in monitoring parameters suggests a low probability of occurrence of this type of activity. Associated hazards consist of the ejection of ballistic pyroclasts, emission of ash and volcanic gases.
2. Quetrupillán Volcanic Complex
Period evaluated: January 1 to 31
GREEN volcanic technical alert remains in place
3. Mocho-Choshuenco Volcanic Complex
Period evaluated: January 1 to 31
GREEN volcanic technical alert is maintained.
4. Carrán-Los Venados Volcanic Field
Evaluated period: January 1 to 31
GREEN volcanic technical alert remains in place
5. Puyehue-Cordón Caulle Volcanic Complex
Period evaluated: January 16 to 31
YELLOW volcanic technical alert maintained
B. Detailed information on each volcanic system
1. VILLARRICA VOLCANO
Seismology
The seismological activity for the period has been characterized by the recording of: A continuous seismic signal of tremor associated with the fluid dynamics inside the volcano, which during this period presented energy ranges between 0.1 and 0.2 μm/s, assessed with the RSAM parameter.
4 VT type seismic events, associated with rock fracturing (Volcano-Tectonic). The most energetic earthquake presented a Local Magnitude (ML) value equal to 1.3, located 4.7 km east-southeast of the volcanic edifice, at a depth of 4.6 km.
2015 LP type seismic events, associated with fluid dynamics within the volcanic system (Long Period). The size of the largest earthquake assessed from the Reduced Displacement (DR) parameter was equal to 12 cm2.
2 TR-type seismic events, associated with the sustained dynamics over time of fluids within the volcanic system (TRemor). The size of the largest earthquake assessed from the Reduced Displacement (DR) parameter was equal to 1 cm2.
Fluid geochemistry
The data on sulfur dioxide (SO2) emissions obtained by the Differential Absorption Optical Spectroscopy (DOAS) equipment, corresponding to the Los Nevados and Tralco stations, installed 10 km in an east-northeast direction and 6 km east-southeast of the active crater respectively, presented an average value of 611 ± 97 t/d for the month of January.
These values are considered normal for this volcanic system. The maximum daily average for the month was 1,548 t/d on January 26. No anomalies were reported in sulfur dioxide (SO2) emissions into the atmosphere in the area near the volcano, according to data published by the Tropospheric Monitoring Instrument (TROPOMI) and Ozone Monitoring Instrument (OMI) Sulfur Dioxide Group (http://so2.gsfc.nasa.gov/).
Geodesy
The geodetic activity for the period has been characterized by low-magnitude displacements in the horizontal and vertical components of the GNSS stations installed in the volcanic system. Rates that do not exceed 0.4 cm/month in the horizontal components and 0.6 cm/month in the vertical components, values similar to previous periods. Therefore, there is no evidence of changes in the internal behavior of the volcano.
Satellite thermal anomalies
During the period, thermal radiance anomalies were recorded in the area associated with the crater of the volcano, according to the analytical processing of Sentinel 2-L2A and Landsat 8-9 satellite images, in combination with false-color bands. The thermal radiance area is 2,400 m2 (Normalized Hotspot Indices algorithm [Marchese et al., 2019]). No thermal alerts were recorded according to data processed by the Middle Infrared Observation of Volcanic Activity (MIROVA, http://www.mirovaweb.it/).
Surveillance cameras
The images provided by the fixed cameras, installed in the vicinity of the volcano, recorded recurrent outgassing columns, with the highest recorded on January 11, reaching 600 m above the level of the crater. The occurrence of explosions with pyroclastic emission on January 7 and 11 stands out, with heights of 140 m and 660 m respectively with dispersion towards the E and S, respectively.
On the other hand, nighttime incandescence was recorded, a condition that has been absent since August 2024, and which has been identified again sporadically and of low intensity, since January 19, 2025.
Satellite geomorphological analysis
Based on the photointerpretation of Skysat Collect images for January 2025 corresponding to the 1st, 21st, 26th and 29th, the observation of exposed melting at depth and with a semicircular area of 5 m in diameter stands out for the first two dates, a feature absent since the end of August 2024.
No morphological changes are identified from Planet Scope or Sentinel 2-L2A images in combination with true-color bands for this volcanic system.
Activity remained at levels considered low, suggesting stability in the volcano. The volcanic technical alert is maintained in:
GREEN TECHNICAL ALERT: Active volcano with stable behavior - No immediate risk
Observation: The monitoring of the surface and instrumental activity of the volcano indicates a decrease in the frequency of explosions with emission of high-temperature volcanic material outside the crater. As it is an open-conduit volcanic system, it is not possible to rule out sudden explosions without precursors. According to what has been observed in previous periods, the impact of these explosions is mostly concentrated at distances of less than 500 m, measured from the center of the crater. However, in the current scenario, the low surface activity together with the decrease in monitoring parameters suggests a low probability of occurrence of this type of activity. Associated hazards consist of the ejection of ballistic pyroclasts, emission of ash and volcanic gases.
5. PUYEHUE-CORDÓN CAULLE VOLCANIC COMPLEX
Seismology
The seismological activity for the period has been characterized by the record of:
86 VT-type seismic events, associated with rock fracturing (Volcano-Tectonic). The most energetic earthquake presented a Local Magnitude (ML) value equal to 1.5, located 1.9 km north of the emission center of 2011, at a depth of 6.3 km.
4 LP type seismic events, associated with the dynamics of fluids within the volcanic system (Long Period). The size of the largest earthquake assessed from the Reduced Displacement (DR) parameter was equal to 28 cm2.
Fluid geochemistry
No anomalies were reported in sulfur dioxide (SO2) emissions into the atmosphere in the sector near the volcanic complex, according to data published by the Tropospheric Monitoring Instrument (TROPOMI) and Ozone Monitoring Instrument (OMI) Sulfur Dioxide Group (http://so2.gsfc.nasa.gov/).
Geodesy
Based on the data obtained through the GNSS network, it is observed that the uplift process continues at similar rates in magnitude with respect to the annual average, evidencing an adjustment of 1.7 cm/month. In turn, from InSar processed in Ovdas on the ISCE platform, it is observed that the inflationary process continues at rates similar to the annual average observed in the complex.
Satellite thermal anomalies
During the period, low power anomalies were recorded in the area, with a maximum Volcanic Radiative Power (PVR) of 1.5 MW on January 31, a value considered low according to the data processed by the VIIRS- Middle Infrared Observation of Volcanic Activity (MIROVA, http://www.mirovaweb.it/) sensor and associated with the area where the laccolith is located. to the NE of the 2011 broadcast centre. Sentinel 2-L2A satellite imagery detected no radiance anomalies. With respect to the processing of Landsat 8-9 images in the thermal band, the maximum temperature obtained corresponds to 38.4°C from the surface, considered as expected for the volcanic system and associated with the area where the laccolith is located.
Surveillance cameras
The images provided by the fixed camera, installed in the vicinity of the volcanic complex, did not register degassing columns or variations associated with surface activity.
Satellite geomorphological analysis
From Planet Scope Scene satellite images (3 m spatial resolution) no morphological changes in the volcanic system are identified.
The activity of the C.V. Puyehue C. Caulle has remained without significant variations compared to recent months. During the period evaluated, seismicity was characterized by a slight decrease in both energy and quantity. Regarding the deformation, the inflationary process continues with rates similar to previous months. Given the continuity of the deformation process and the presence of seismicity, the technical alert is maintained in:
YELLOW TECHNICAL ALERT: Changes in the behavior of volcanic activity
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