Union City, CA Weather

Updated:  Fri, 09-May-2025 12:40am EDT 
  clear Temperature: 57.9°F   /hr Humidity: 80% Dew Point: 51.8 Wind: WSW  0.0 mph Gust: 0.0 mph Pressure: 30.045 inHg  Steady Rain Today: 0.00 in UV-index: 0.0  None

Volcanic Activity Reports

Volcanoes – The Watchers

• The Weekly Volcanic Activity Report: April 30–May 6, 2025
  May 8 2025 at 04:06:51 UTC
  New activity/unrest was reported for 6 volcanoes from April 30 to May 6, 2025. During the same period, ongoing activity was reported for 20 volcanoes.

  Source

• Explosions and pyroclastic flows at Santa Maria volcano, Guatemala
  May 7 2025 at 12:55:09 UTC
  High-level explosive activity at Santa María’s Santiaguito dome complex on May 6, 2025, produced ash plumes up to 900 m (2 950 feet) above the crater and pyroclastic flows down the southern and southwestern flanks.

  Source

• Tectonic link found between Ontong Java Plateau and Louisville hotspot chain
  May 7 2025 at 12:16:00 UTC
  A new study from the University of Maryland and the University of Hawaiʻi has revealed surprising connections between two major volcanic features in the Pacific. By tracing the Louisville hotspot as the source of both the Ontong Java Plateau and a series of underwater volcanoes, the researchers have uncovered fresh insights into the Pacific Ocean's geological history. This discovery challenges old ideas and offers a clearer picture of how the seafloor and the islands above it have formed over millions of years.

  Source

• First real-time observation of volcanic eruption on a mid-ocean ridge
  May 7 2025 at 03:36:03 UTC
  Scientists aboard the Alvin submersible witnessed an active volcanic eruption at the Tica hydrothermal vent on April 29, 2025, along the East Pacific Rise. The event, which buried a vibrant ecosystem under fresh lava, marks the first confirmed real-time observation of such an event on a mid-ocean ridge.

  Source

• Unrest at dormant Uturuncu volcano driven by gas and fluid movement, not magma
  May 6 2025 at 04:51:07 UTC
  A new study published in PNAS provides the most detailed view to date of the dormant Uturuncu volcano in southwestern Bolivia, revealing that its long-standing ground deformation and seismic unrest are driven by the movement of hot fluids and gases, not by magma ascent. Researchers conclude there is no immediate eruption risk, but confirm that a deep magmatic system remains active beneath the surface.

  Source

Worldwide Volcano News

• Volcanoes Today, 9 May 2025: Popocatépetl volcano, Semeru, Ibu, Svartsengi, Reventador, Poas, Raung, Sangay
  May 9 2025 at 2:00 am EDT
  


• Svartsengi volcano update: uplift continues
  May 9 2025 at 1:43 am EDT
  
  The new hazard map relating to the current seismic unrest under the area (image: Icelandic Met Office)

  Recent GPS deformation data continue to detected the uplift in the Svartsengi area, although the rate of the ground swell has slowed in recent weeks.
  Scientists are currently evaluating when the likelihood of a new magma intrusion or eruption might rise. Their assessment is based on the assumption that the same volume of magma must accumulate beneath Svartsengi as in previous events along the Sundhnúkur crater row.
  Experts at the Icelandic Meteorological Office are revising the possible scenarios, including the estimated volume of magma needed beneath Svartsengi to trigger another dike formation or eruption.
  While the deformation data indicate continued uplift, short-term daily fluctuations are common and may not reflect true changes in magma inflow. These variations can result from weather conditions, measurement inaccuracies, or natural variability and usually have little impact on the broader trend. Therefore, scientists emphasize the importance of analyzing weekly or longer-term data to accurately understand ongoing geological processes.
  The seismic activity is still being detected along the dike that formed on April 1, though the number of earthquakes has decreased since the eruption ended. Over the past two weeks, several dozen earthquakes have been recorded daily on average.
  The hazard assessment map has been updated and will remain in effect until May 20 unless new developments occur.
  Source: Icelandic Meteorological Office volcano activity update 9 May 2025

  
  


• Semeru Volcano Volcanic Ash Advisory: VA ERUPTION LAST REPORTED AT 09/0252Z EST VA DTG: 09/0420Z
  May 9 2025 at 12:45 am EDT
  
  
  


• Nevado del Ruiz Volcano Volcanic Ash Advisory: NO VA OBS
  May 8 2025 at 11:45 pm EDT
  
  
  


• Popocatépetl Volcano Volcanic Ash Advisory: DISCRETE VA EM to 21000 ft (6400 m)
  May 8 2025 at 11:15 pm EDT
  
  
  


• Poas Volcano Volcanic Ash Advisory: VA EMS ONGOING
  May 8 2025 at 10:15 pm EDT
  
  
  


• Raung Volcano Volcanic Ash Advisory: VA TO FL140 REPORTED AT 08/2209Z OBS VA DTG: 09/0100Z to 14000 ft (4300 m)
  May 8 2025 at 9:30 pm EDT
  
  
  


• Sangay Volcano Volcanic Ash Advisory: ONGOING VA EMS to 22000 ft (6700 m)
  May 8 2025 at 7:30 pm EDT
  
  
  


• Ibu Volcano Volcanic Ash Advisory: VA TO FL070 OBS AT 08/2300Z MOV SW EST VA DTG: 08/2300Z to 7000 ft (2100 m)
  May 8 2025 at 7:30 pm EDT
  
  
  


• Reventador Volcano Volcanic Ash Advisory: VA EMS ONGOING to 15000 ft (4600 m)
  May 8 2025 at 7:00 pm EDT
  
  
  


• Volcanic activity worldwide 8 May 2025: Santiaguito volcano, Fuego, Semeru, Ibu, Dukono, Reventador,...
  May 8 2025 at 6:00 pm EDT
  
  Map of today's active volcanoes
  Canlaon (Central Philippines): (8 May) Volcanic Ash Advisory Center Tokyo (VAAC) issued the following report: ERUPTION AT 20250508/0830Z FL090 EXTD NW REPORTED OBS VA DTG:08/0830Z
  
  Ibu (Halmahera, Indonesia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 7000 ft (2100 m) altitude or flight level 070 and is moving at 05 kts in W direction.
  The full report is as follows: VA TO FL070 LAST REPORTED AT 08/0912Z EST VA DTG:08/1120Z to 7000 ft (2100 m)
  
  Semeru (East Java, Indonesia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 15000 ft (4600 m) altitude or flight level 150 and is moving at 05 kts in N direction.
  The full report is as follows: VA TO FL150 LAST REPORTED AT 08/1500Z MOV N to 15000 ft (4600 m)
  
  Dukono (Halmahera): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 9000 ft (2700 m) altitude or flight level 090 and is moving at 05 kts in NE direction.
  The full report is as follows: CONTINUOUS VA EMISSIONS TO FL090 OBS MOV NE AT 08/1550Z to 9000 ft (2700 m)
  
  Santiaguito (Guatemala): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: VA EMS ONGOING
  
  Fuego (Guatemala): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 15000 ft (4600 m) altitude or flight level 150 .
  The full report is as follows: FREQUENT VA EMS to 15000 ft (4600 m)
  
  Poas (Costa Rica): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: VA EMS ONGOING EST VA DTG:08/1940Z
  
  Nevado del Ruiz (Colombia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 20000 ft (6100 m) altitude or flight level 200 .
  The full report is as follows: NEW VA EMS to 20000 ft (6100 m)
  
  Sangay (Ecuador): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: PSBL VA EMS
  
  Reventador (Ecuador): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: ONGOING VA EMS
  
  


• Nevado del Ruiz Volcano Volcanic Ash Advisory: NEW VA EMS to 20000 ft (6100 m)
  May 8 2025 at 5:15 pm EDT
  
  
  


• Santiaguito Volcano Volcanic Ash Advisory: VA EMS ONGOING
  May 8 2025 at 5:00 pm EDT
  
  
  


• Poas Volcano Volcanic Ash Advisory: VA EMS ONGOING EST VA DTG: 08/1940Z
  May 8 2025 at 4:15 pm EDT
  
  
  


• Sangay Volcano Volcanic Ash Advisory: PSBL VA EMS
  May 8 2025 at 1:30 pm EDT
  
  
  


• Semeru Volcano Volcanic Ash Advisory: VA TO FL150 LAST REPORTED AT 08/1500Z MOV N to 15000 ft (4600 m)
  May 8 2025 at 12:45 pm EDT
  
  Satellite image of Semeru volcano on 8 May 2025
  
  


• Dukono Volcano Volcanic Ash Advisory: CONTINUOUS VA EMISSIONS TO FL090 OBS MOV NE AT 08/1550Z to 9000 ft (2700 m)
  May 8 2025 at 12:15 pm EDT
  
  Satellite image of Dukono volcano on 8 May 2025
  
  


• Fuego Volcano Volcanic Ash Advisory: FREQUENT VA EMS to 15000 ft (4600 m)
  May 8 2025 at 8:15 am EDT
  
  
  


• Ibu Volcano Volcanic Ash Advisory: VA TO FL070 LAST REPORTED AT 08/0912Z EST VA DTG: 08/1120Z to 7000 ft (2100 m)
  May 8 2025 at 7:45 am EDT
  
  Satellite image of Ibu volcano on 8 May 2025
  
  


• Reventador Volcano Volcanic Ash Advisory: ONGOING VA EMS
  May 8 2025 at 7:15 am EDT
  
  
  


• Santiaguito Volcano Volcanic Ash Advisory: MINOR VA EMS to 13000 ft (4000 m)
  May 8 2025 at 5:15 am EDT
  
  
  


• Canlaon Volcano Volcanic Ash Advisory: ERUPTION AT 20250508/0830Z FL090 EXTD NW REPORTED OBS VA DTG: 08/0830Z
  May 8 2025 at 5:00 am EDT
  
  
  


• Poas Volcano Volcanic Ash Advisory: PSBL VA EMS to 10000 ft (3000 m)
  May 8 2025 at 4:30 am EDT
  
  
  


• Volcanic activity worldwide 7 May 2025: Santiaguito volcano, Fuego, Semeru, Ibu, Dukono, Marapi, Rev...
  May 7 2025 at 5:00 pm EDT
  
  Map of today's active volcanoes
  Ibu (Halmahera, Indonesia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 7000 ft (2100 m) altitude or flight level 070 and is moving at 05 kts in S direction.
  The full report is as follows: VA TO FL070 REPORTED AT 07/0513Z EST VA DTG:07/1120Z to 7000 ft (2100 m)
  
  Semeru (East Java, Indonesia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 15000 ft (4600 m) altitude or flight level 150 and is moving at 10 kts in NW direction.
  The full report is as follows: VA TO FL150 REPORTED AT 07/0212Z EST VA DTG:07/1020Z to 15000 ft (4600 m)
  
  Marapi (Western Sumatra, Indonesia): (7 May) Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 12000 ft (3700 m) altitude or flight level 120 .
  The full report is as follows: VA TO FL120 REPORTED FM GND AT 06/2306Z MOV N to 12000 ft (3700 m)
  
  Dukono (Halmahera): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 8000 ft (2400 m) altitude or flight level 080 .
  The full report is as follows: VA OBS TO FL080 AT 07/1100Z MOV SE OBS VA DTG:07/1100Z to 8000 ft (2400 m)
  
  White Island (New Zealand): (7 May) Volcanic Ash Advisory Center Wellington (VAAC) issued the following report: ERUPTION AT 20250503/0040Z WEAK LOW LEVEL ERUPTION, NO ASH IDENTIFIABLE
  
  Kilauea (Hawai'i): Episode 20 ended at 9:58 p.m. HST on Tuesday, May 6, 2025, after 4.5 hours of sustained fountaining, the Hawaiian Volcano Observatory (HVO reported. The Halema'uma'u eruption is currently paused.
  "The sustained fountaining phase of episode 20 began at 5:28 p.m. on Tuesday, May 6, 2025. Lava fountains and flows erupted from both vents, but the north vent was much more active than the south vent during all phases of episode 20. Fountains from the north vent quickly reached estimated heights of more than 500 feet (150 meters). Fountains from the south vent reached heights of up to about 65 feet (20 meters). It is currently estimated that lava flows from this episode covered less than half of the Halema'um'au crater floor. The sustained fountaining phase was preceded by almost 31 hours of precursory low-level activity that included gas-pistoning events in the north vent that produced low lava dome fountains, overflows, and drainbacks, as well as sluggish lava flows from the south vent.
  ... [read more] ... [show less]
  "The end of episode 20 fountaining activity was accompanied by a rapid change in summit tilt from deflation to inflation, along with a rapid decrease in tremor. The Uēkahuna tiltmeter (UWD) recorded approximately 6 microradians of deflationary tilt between the start and end of episode 20 fountaining.
  
  ...7 May:
  The 20th lava fountaining episode began from the active vents at Halema'uma'u summit crater a short time ago, at 5:28 p.m. HST local time on May 6, 2025.
  The Hawaiian Volcano Observatory (HVO) reported: "..cyclic gas-pistoning transitioned to continuous eruption of lava fountains that grew rapidly in vigor and height. Fountains from the north vent quickly reached heights of greater than 500 ft (150 m). North vent lava fountains are feeding fast moving lava flows that are covering the floor of Halema'uma'u crater, including a flow that poured over the south vent. The south vent is not showing signs of increased activity at this time."
  ... [read more] ... [show less]
  "The onset of sustained fountaining was accompanied by a rapid change in summit tilt from inflation to deflation along with a rapid increase in tremor. The Uēkahuna tiltmeter (UWD) recorded approximately 8 microradians of inflationary tilt between the end of episode 19 and the beginning of episode 20 sustained fountaining.
  "Episode 20 sustained fountaining was preceded by just under 31 hours of precursory low-level activity that included gas-pistoning events in the north vent that produced low lava dome fountains, overflows, and drainbacks, as well as sluggish lava flows from the south vent."
  
  
  Santiaguito (Guatemala): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 14000 ft (4300 m) altitude or flight level 140 .
  The full report is as follows: DISCRETE VA EM. to 14000 ft (4300 m)
  
  Fuego (Guatemala): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: VA EMS ONGOING
  
  Poas (Costa Rica): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 10000 ft (3000 m) altitude or flight level 100 .
  The full report is as follows: CONS LGT VA EMS. to 10000 ft (3000 m)
  
  Sangay (Ecuador): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 24000 ft (7300 m) altitude or flight level 240 and is moving at 15 kts in W direction.
  The full report is as follows: OCNL TO FRQT VA EMS. to 24000 ft (7300 m)
  
  Reventador (Ecuador): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: FREQUENT VA EMS
  Volcano Activity Summary for 7 May 2025:
  Satellite image of Ibu volcano on 7 May 2025
  
  


• Karymsky volcano (Russia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that thermal anomalies over Karymsky were identified in satellite images during 24 and 28-30 April and on 1 May. Explosive activity began on 29 April and ash plumes generated during 29-30 April and on 1 May drifted 120 km SE, E, and NE. KVERT issued a Volcano Observatory Notice for Aviation (VONA) noting that explosions occurred at 1320 and 1830 on 30 April; the ash plume from the second explosion rose 3.5-4 km (11,500-13,100 ft) a.s.l.
  Dates are based on UTC times; specific events are in local time where noted.
  
  Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
  ---
  From: Global Volcanism Program, 2025. Report on Karymsky (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Kilauea volcano (United States) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, from two vents along the SW margin of Halema’uma’u Crater, continued at variable levels during 22 April-6 May. Incandescence at the S vent was visible during 22-25 April, then at both the N and S vents during 26 April-1 May. Weak spattering at the N vent was visible just before 1850 on 27 April.
  A tiny lava pool at the S vent was visible overnight during 29-30 April. Spattering at the N vent was visible along with flames from hydrogen gas burning in air during 29 April-1 May. Sulfur dioxide emissions averaged 1,350 tonnes per day (t/d) on 30 April, typical levels during periods with no lava fountains.
  
  
  
  At the N vent, cycles of dome fountaining, short lava overflows, and lava immediately draining back into the vent began at around 1149 on 1 May and lasted above nine hours. There were 26 cycles, with each lasting 10-15 minutes separated by about 10 minutes of repose. The activity intensified at around 1845.
  Lava fountains became sustained at 2128 and rose up to 100 m. Fountaining lasted for seven hours and 52 minutes, ceasing at 0520 on 2 May. Lava flows covered about half of the crater floor.
  Sulfur dioxide emissions averaged 1,750 t/d later that same day. Incandescence at both vents was visible overnight during 3-5 May. Occasional spattering at the N vent was visible during 4-5 May.
  Activity increased on 5 May. During 1049-1800 there were about 30 cycles of dome fountaining and lava draining back into the N vent. Lava overflowed the vent rim several times producing short lava flows.
  At 1123 a short lava flow from the S vent advanced onto the crater floor. Incandescence from both vents was visible overnight during 5-6 May. Lava fountaining at the N vent began at 1728 on 6 May and fountains quickly rose at least 150 m.
  Fast-moving lava flows traveled across the crater floor. Fountains also rose from the S vent as high as 20 m. Fast-moving lava flows from mainly the N vent and somewhat from the S vent traveled across the crater floor, covering less than half of it.
  Activity ceased at 2158. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
  
  Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
  ---
  From: Global Volcanism Program, 2025. Report on Kilauea (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Lewotobi volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Lewotobi Laki-laki continued during 30 April-6 May. Daily white plumes rose as high as 700 m above the crater rim and drifted in various directions. At 0522 on 30 April a dense gray ash plume rose 4 km above the crater rim and drifted N and NE.
  Incandescent material on the flanks was possibly visible in a webcam image from 0535. At 1107 on 2 May a dense gray-to-brown ash plume rose 3.5 km above the crater rim and drifted N and NE. Ash plumes at 1200 on 2 May and at 2106 on 3 May rose 1 km and 800 m above the crater rim, respectively, and drifted SW and W.
  The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 6 km away from the center of Laki-laki.
  
  Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
  ---
  From: Global Volcanism Program, 2025. Report on Lewotobi (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Great Sitkin volcano (United States) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin’s summit crater during 29 April-6 May. Small daily earthquakes were detected by the seismic network. Slightly elevated temperatures were identified in a few satellite images during 30 April-1 May.
  Weather clouds often obscured satellite and webcam views of the volcano. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
  
  Source: US Geological Survey Alaska Volcano Observatory (AVO)
  ---
  From: Global Volcanism Program, 2025. Report on Great Sitkin (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Etna volcano (Italy) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Sezione di Catania - Osservatorio Etneo (INGV) reported continuing activity at Etna during 28 April-4 May, characterized by Strombolian activity, lava fountains, and lava overflows at SE Crater and gas emissions at Bocca Nuova Crater, NE Crater, and Voragine. Activity at SE Crater began at 2357 on 29 April based on webcam views, though the views were obscured by dense weather clouds during the first hour. Visibility significantly improved at about 0200 on 30 April and by then lava was flowing over the SE Crater rim, with several branches advancing to the SE and S.
  Multiple vents at the summit of SE Crater produced explosive activity at variable intensities, with jets of material rising 300-400 m high. Strombolian explosions at the main vent in the W part of the crater became sustained at around 0245 producing pulsating lava fountains. Lava flows reached the base of the cone and fanned out towards Monte Frumento Supino.
  The activity decreased at around 0330 with lava fountaining changing to Strombolian activity that lasted for about three hours. By 0615 Strombolian activity was no longer visible and ash emissions rose 1,5 km above the summit and drifted SW. The ash emissions became discontinuous and then ceased at 0910.
  Satellite data from 2 May was used to map the flows. Both the SE and S flows were about 1.6 km long.
  
  Source: Sezione di Catania - Osservatorio Etneo (INGV)
  ---
  From: Global Volcanism Program, 2025. Report on Etna (Italy). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Lewotolok volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 30 April-5 May. Daily white steam-and-gas plumes rose as high as 100 m above the summit of the cone and drifted NW, W, and SW. Nighttime webcam images showed incandescent material being ejected above the summit.
  Ash plumes rose 400-600 m and drifted SE and W during 3-4 May. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks.
  
  Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
  ---
  From: Global Volcanism Program, 2025. Report on Lewotolok (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Ibu volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) lowered the Alert Level for Ibu to 2 (the second lowest level on a four-level scale) at 1700 on 1 May, based on visual observations and monitoring data that showed decreasing activity since February. Eruptive activity continued to be recorded, though plumes heights were lower and incandescent material was ejected only as far as 200 m from the crater rim. Seismic activity had decreased, and deformation data showed some signs of decreased pressure, or deflation.
  Daily gray, white-to-gray, or white-to-brown ash plumes rose 300-700 m above the crater rim and drifted in variable directions. Nighttime crater incandescence was visible in some webcam images. The public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening.
  
  Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
  ---
  From: Global Volcanism Program, 2025. Report on Ibu (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Kanlaon volcano (Philippines) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 29 April-5 May. The seismic network recorded 7-22 daily volcanic earthquakes. Daily sulfur dioxide emissions ranged from 457 to 2,794 tonnes per day; emissions were not reported on 3 May.
  Gas-and-steam plumes with moderate densities rose 150-600 m above the crater rim and drifted NW, W, and SW. The plumes occasionally contained ash on 29 April. The Alert Level remained at 3 (on a scale of 0-5); the public was warned to stay 6 km away from the summit and pilots were warned not to fly close to the volcano.
  
  Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
  ---
  From: Global Volcanism Program, 2025. Report on Kanlaon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Nyamulagira volcano (DR Congo) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  Satellite images acquired on 21 and 26 April and on 1 May showed continuing activity at Nyamulagira. Though weather clouds particularly obscured the summit area in all three scenes, bright thermal anomalies indicated continuing activity at the summit crater and active lava flows on the W flank.
  
  Source: Copernicus
  ---
  From: Global Volcanism Program, 2025. Report on Nyamulagira (DR Congo). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Sheveluch volcano (Russia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that lava extrusion may have continued at Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 24 April-1 May. Daily thermal anomalies over the domes were identified in satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
  Dates are based on UTC times; specific events are in local time where noted.
  
  Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
  ---
  From: Global Volcanism Program, 2025. Report on Sheveluch (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Suwanosejima volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 28 April-5 May. Incandescence was observed nightly in webcam images. An explosion at 0901 on 5 May generated an ash plume that rose 700 m above the crater rim and drifted S.
  The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to be cautious within 1.5 km of the crater.
  
  Source: Japan Meteorological Agency (JMA)
  ---
  From: Global Volcanism Program, 2025. Report on Suwanosejima (Japan). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Semeru volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 30 April-6 May, with multiple daily eruptive events recorded by the seismic network. Daily white-and-gray ash plumes rose 400-1,000 m above the summit and drifted in multiple directions. The Alert Level remained at 2 (the second lowest level on a scale of 1-4).
  The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.
  
  Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
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  From: Global Volcanism Program, 2025. Report on Semeru (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Reventador volcano (Ecuador) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 9-15 April. Seismicity included 57-100 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Multiple daily ash-and-gas plumes rose 300-1,300 m above the crater rim and drifted mainly NW, W, and SW.
  Webcams recorded multiple nightly instances of incandescent material descending the flanks as far as 1.1 km below the crater rim, particularly down the S and SE flanks. Weather clouds occasionally obscured views. Secretaría de Gestión de Riesgos maintained the Alert Level at Orange (the second highest level on a four-color scale).
  
  Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Secretaría de Gestión de Riesgos (SGR)
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  From: Global Volcanism Program, 2025. Report on Reventador (Ecuador). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Merapi volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 25 April-1 May. Seismicity remained at high levels. The SW lava dome produced 62 lava avalanches that traveled as far as 2 km SW down the Bebeng drainage, 47 that traveled as far as 2 km SW down the Krasak drainage, and 148 that traveled as far as 2 km W down the Sat/Putih drainage.
  Small morphological changes to the SW lava dome resulted from continuing effusion and minor collapses of material. The hottest temperature was 249.3 degrees Celsius, and the volume of the dome had grown to an estimated 3,925,200 cubic meters, based on webcam images and a 26 April drone survey. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit, based on location.
  
  Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)
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  From: Global Volcanism Program, 2025. Report on Merapi (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Popocatepetl volcano (Mexico) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 29 April-4 May. The seismic network recorded 11-35 long-period events per day, accompanied by steam-and-gas emissions; ash was detected in the emissions during 29-30 April. In addition, the seismic network recorded daily periods of tremor, sometimes characterized by harmonic and high-frequency signals, lasting from 34 minutes to three hours and 52 minutes.
  According to the Washington VAAC an ash plume was visible in webcam and satellite images on 10 April rising 5.8 km (20,000 ft) a.s.l. (about 400 m above the crater rim) and drifting SW. An event at around 0100 on 5 May ejected material onto the upper flanks and produced an ash plume that rose 6.4 km (21,000 ft) a.s.l. (as high as 1 km above the crater rim) and drifted E and ESE.
  The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater.
  
  Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
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  From: Global Volcanism Program, 2025. Report on Popocatepetl (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.

  
  


• Marapi volcano (Indonesia) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 April-6 May 2025 (Continuing Activity)
  May 7 2025 at 10:00 am EDT
  

  The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity from Verbeek Crater at Marapi (on Sumatra) continued during 30 April-6 May. Eruptive events were detected at 1816 on 30 April and at 1438 on 1 May, though the events were not visually observed. At 1812 on 3 May an ash plume rose 800 m above the summit and drifted NE.
  An eruptive event was detected at 1331 on 4 May, though not visually observed. At 2209 on 4 May a dense gray ash plume rose 1 km above the summit and drifted E. Incandescence at the summit was visible in an image from 2226 that same day.
  The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater.
  
  Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
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  From: Global Volcanism Program, 2025. Report on Marapi (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report 30 April-6 May 2025. Smithsonian Institution and US Geological Survey.