Eruptions

News about eruptions and volcanoes can be found in this category. It is updated frequently. Volcano expert and journalist Marc Szeglat reports live from his expeditions to volcanoes.

Ol Doinyo Lengai: Thermal Anomaly Suggests Lava Overflow

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Thermal Anomaly at Ol Doinyo Lengai Suggests Lava Overflow

Tanzania’s Ol Doinyo Lengai, the world’s only active volcano erupting sodium-carbonatite lava, is showing signs of increased activity. A Sentinel satellite captured a significant thermal anomaly on May 27 that filled the entire summit crater—an unusual event for a volcano whose lava, at just 500–600°C, is too cool to glow visibly during the day.

Normally, small infrared hotspots hint at active hornitos—small lava vents—but the scale of this anomaly suggests a lava overflow, possibly triggered by the collapse of a hornito and the release of a lava pond across the crater floor.

Increased thermal signals have persisted in subsequent satellite imagery. These observations align with earlier geophysical data collected by an international team led by Sarah Stamps and Ntambila Daud of Virginia Tech. Since 2016, six GNSS stations installed around the volcano have monitored subtle ground deformation. Between March and December 2022, researchers detected rapid uplift, followed by steady elevation through August 2023. No deformation was recorded before or after, and modeling suggests the activity was caused by a shallow magmatic intrusion—potentially marking a phase of volcanic heating.

Despite these signs, on-site observations remain rare. Post-pandemic cost hikes have sharply reduced expeditions to the remote Rift Valley region. Even fewer eyewitness reports come from Nyamuragira volcano in the Democratic Republic of Congo, where insecurity and conflict near Goma further hinder access. Nyamuragira remains far more active than Lengai, emitting thermal energy levels over 1,980 megawatts—compared to just single-digit values at Ol Doinyo Lengai.

Kīlauea: Eruption No. 24 Produces Spectacular Lava Fountain

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The 24th eruption episode has begun at Kilauea – lava fountain 300 m high

Hilo, June 5, 2025

Hawaiʻi’s Kīlauea volcano has erupted again: the 24th eruption of the current phase, ongoing since December 23, 2024, began overnight. A lava fountain over 300 meters high shot lava up to the rim of Halemaʻumaʻu crater, while large lava flows now cover its entire floor.

The eruption started on June 4 at around 9:15 PM HST (07:15 UTC, June 5), with initial fountains reaching about 30 meters. By 10:27 PM HST, activity had intensified significantly, with fountains reaching 150 meters — and shortly after, exceeding 300 meters. The main activity is from the northern vent, while the southern vent is producing a smaller, 50-meter-high fountain.

Warning signs appeared in the afternoon, with intermittent lava spattering. A lava flow began shortly before the fountain activity — a typical paroxysmal pattern, also seen recently at Etna and Fuego.

Significant ground inflation of about 12 µRad was recorded after the previous eruption on May 26 — one of the highest values since episodic activity resumed, indicating a strong paroxysm with potential for further escalation.

Authorities are closely monitoring the situation. While there is currently no direct threat to the public, visitors to Hawaiʻi Volcanoes National Park are strongly urged to stay within designated safety zones.

Fuego: Pyroclastic Flows During Intense Eruption

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Pyroclastic flows cause evacuations at Fuego

Antigua, June 5, 2025

Guatemala’s Fuego volcano experienced a paroxysmal eruption overnight, producing lava fountains up to 300 m high, lava flows, and several pyroclastic flows that reportedly reached near the base of the volcano.

The national volcano institute INSIVUMEH issued a warning in a Spanish-language bulletin, shared only as an image on social media — making translation difficult and limiting access to critical information, especially for foreign tourists. This reflects a broader global issue in emergency communication.

Later, the civil protection agency CONRED released a translatable bulletin confirming pyroclastic density currents in the Seca, Ceniza, and Las Lajas ravines. These were classified as weak to moderate but could intensify. Ashfall affected several towns west and northwest of the volcano, particularly Acatenango and San Pedro Yepocapa.

The situation remains critical in southern areas. Emergency teams are patrolling and monitoring local communities. Road RN 14 was closed due to the threat of pyroclastic flows crossing it.

CONRED urged the tourism authority INGUAT and local governments to restrict access to nearby Acatenango volcano. 500 residents were evacuated. Both residents and tourists were advised to stay informed and keep a 72-hour emergency bag ready in case evacuation becomes necessary.

Etna: Major Pyroclastic Flow on the Eastern Flank

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Pyroclastic Flow on the Eastern Flank of Etna – many people close to the eruption

Catania, June 2, 2025 – 11:45 AM

During Etna’s 14th eruptive phase — considered a mild paroxysm — a pyroclastic flow unexpectedly occurred at 11:24 AM CEST. It originated from the northeastern flank of the Southeast Crater and surged through the Valle del Bove, partially reaching the Valle del Leone.

The flow was likely triggered by the collapse of a lava flow or a section of the crater flank due to the ongoing activity. Pyroclastic flows on Etna often result from lava breaking through the cone’s sides, causing structural collapse.

Preliminary assessments suggest this was one of the largest pyroclastic flows ever observed at Etna. The INGV later stated the flow likely did not extend beyond the Valle del Leone’s boundary — crucial, as this ridge (Serra delle Concazze) is frequented by hikers.

Simultaneously, strombolian activity intensified into a lava fountain. It remains unclear whether a sudden pressure build-up caused the collapse or whether the collapse itself triggered explosive decompression of magma. Volcanic ash was detected at 6,400 m altitude, prompting a red alert from VAAC Toulouse.

Recent monitoring indicated magma accumulation beneath the Southeast Crater in a north-south trending zone. Previous eruptions had already revealed new vents on the northwest side, suggesting structural weakness.

This incident highlights the unpredictability and danger of volcanoes — and raises concerns about tourist safety. While access to Stromboli is strictly limited even during normal activity, visitors are transported by cable car and bus to within 300 m of Etna’s active craters — despite significantly higher eruption levels. A glaring safety gap that demands attention.

Eruption No. 8 Begins at Sundhnúkur

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Eruption and dyke formation at Sundhnúkur – Lava Flows Toward Grindavík

This morning at 9:47 a.m. local time (11:47 a.m. CEST), the anticipated volcanic eruption began on the Reykjanes Peninsula in Iceland. Once again, a fissure opened in the Sundhnúkur crater system—this time significantly farther south than in previous eruptions. The new fissure cuts through the protective barrier built north of Grindavík, and lava is now flowing toward the town.

Unlike the eruptions in the latter half of 2024, today’s event was preceded by a powerful earthquake swarm. Interestingly, the Icelandic Meteorological Office (IMO) had yet to update its shakemaps early this morning, suggesting the new data was not incorporated until office hours began. However, Icelandic media outlet MBL reported early signs of a magma intrusion underground. Initial earthquake data did not reflect unusual activity, leading some to briefly suspect an April Fool’s hoax—proof that even a date can be deceiving.

But the eruption is very real. Live camera footage shows that a new fissure has opened south of the volcanic ridge of Hagafell. The fissure is estimated to be about 500 meters long, though the lava fountains are currently less intense than in previous eruptions. Given that the eruption began just over an hour ago, the event may still be in its early stages and could intensify. Further fissures are also a possibility.

Grindavík was evacuated immediately as the seismic crisis began this morning, though eight residents reportedly refused to leave. As of this writing, the fissure has extended dangerously close to a greenhouse near the town. However, the main fissure appears to be expanding northward—away from Grindavík. The nearby Svartsengi geothermal plant is currently not under direct threat. Lava is primarily spreading toward Mount Þorbjörn.

According to the IMO, the magmatic dike driving this eruption is over 11 kilometers long, making it the largest intrusion of its kind since November 2023. Scientists believe that this may be more than just a release of previously accumulated magma. The intensity of seismic activity suggests that fresh magma from greater depths may also be rising to the surface.

As the situation evolves, authorities are monitoring the eruption closely, ready to respond to any changes in the lava flow direction or eruption intensity.

Subterminal Eruption at Mount Etna

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Subterminal Eruption at Mount Etna: Lava Flow on the Southern Flank

After several months of inactivity, Mount Etna in Sicily has erupted again, producing a lava flow descending its southern flank. Notably, this is a rare subterminal eruption: instead of originating from the central crater, the lava flow emerges from a short fissure at the base of the central crater complex.

According to INGV volcanologist Boris Behnke, the eruption likely began in the afternoon but only became visible after nightfall. Since Thursday, volcanic tremor has been increasing, indicating rising magma. Additionally, weak Strombolian eruptions and ash emissions were observed.

Seismic activity beneath Etna had already intensified last month, suggesting magma ascent. Whether this magma has reached the surface remains uncertain. More likely, the rising magma increased pressure in a shallow reservoir, forcing stored molten rock to escape. The gas pressure is insufficient for an explosive eruption from the main craters, but if larger volumes of fresh magma reach higher levels of the conduit system, paroxysmal eruptions could occur.

Kilauea: A sudden volcanic eruption at 23th December

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A sudden volcanic eruption occurred today at Kilauea in Hawaii. The eruption began at 2:20 AM HST (13:20 UTC), rapidly filling the Halemaʻumaʻu Crater with lava within minutes.

A livestream captured the moment when a fissure opened in the western part of the crater and quickly expanded. A powerful but short-lived lava fountain erupted from a previous eruption site. Within 35 minutes, lava had spread across most of the crater floor, forming a new lava lake. This lake continues to be fed by an active lava fountain at the western crater rim.

The eruption was preceded by a brief seismic crisis that began around 2:00 AM HST. Over the past 24 hours, more than 180 earthquakes were recorded, with increased seismic activity already detected yesterday. Surprisingly, there was no significant ground inflation, which is typically observed in the days and weeks before an eruption.

Kilauea, one of the world’s most active volcanoes, last showed heightened seismic activity on December 4. This sudden eruption serves as a reminder of how unpredictable volcanic activity can be.

Stronger Explosion generated a Pyroclastic Flow at Kanlaon

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After strong explosion on Kanlaon: Alert Level Raised to “3”

Today, the Philippine volcano Kanlaon experienced a stronger explosion, resulting in volcanic ash rising and generating a pyroclastic density current. According to the Tokyo VAAC, the ash cloud reached an altitude of 6,700 meters and drifted westward, while the pyroclastic flow descended the volcano’s southeastern flank. Based on video footage, I estimate its glide distance to be approximately 2,800 to 3,000 meters. The footage also shows a shock wave rippling through the clouds.

Iceland: New eruption on 20th November

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On the evening of November 20, 2024, a new fissure eruption unexpectedly occurred along the Sundhnúkur crater row in Iceland. Volcanologists had not anticipated an eruption in November, as seismic activity had remained low in recent days. However, seismicity began to slowly increase by midday, without any clear warning signs. It wasn’t until 30 minutes before the eruption that a geothermal power plant operator reported rising pressure in boreholes, accompanied by a small earthquake swarm. The eruption began at approximately 11:14 PM local time.

A fissure approximately three kilometers long opened between Stóri Skógfell and Sýlingarfell. Three parallel fractures formed, emitting lava fountains. Two lava flows are moving north and west. The northern flow poses no threat to infrastructure, while the western flow is heading toward the Svartsengi geothermal power plant. Protective barriers are expected to shield the plant from the lava, which is advancing at a speed of 300 meters per hour. The main road to Grindavik has already been disrupted.

The intensity of the eruption remains uncertain. Although it appears smaller than the previous two eruptions, it could last longer, as more than 23 million cubic meters of magma have accumulated since September. The situation continues to develop unpredictably.

Lewotobi Lakilaki: Volcanic eruption causes fatalities

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At least 10 people die at Lewotobi Lakilaki – Volcanic ash reaches 12,000 meters

Last night, a volcanic disaster occurred on the Indonesian island of Flores when Lewotobi Laki-Laki erupted violently. The exact sequence of the eruption is still not fully clarified. Around midnight local time, there was apparently a strong explosion, and ash and glowing tephra reached inhabited areas. Several buildings, including a Catholic monastery at the foot of the volcano, caught fire and burned down. At least ten people lost their lives, and several others were injured. The Volcanic Ash Advisory Center (VAAC) issued a VONA warning, reporting volcanic ash reaching up to 12,000 meters. The eruption cloud split and drifted in two directions: one cloud was blown westward, the other southeast. The alert level was raised from “Orange” to “Red.” The exclusion zone was expanded from 4 kilometers to 7 kilometers.