Volcano Erupts Amid Lightning Storm in Indonesia, as Residents Evacuate Potential Tsunami Threat

Plumes of ash from Mount Ruang forced the closure of an international airport, after a series of at least five eruptions this week

a volcano on an island spewing ash at sunrise
Mount Ruang in North Sulawesi, Indonesia, spews ash on April 19, 2024, after a series of eruptions earlier this week launched molten rocks into the sky. RONNY ADOLOF BUOL / AFP via Getty Images

Dramatic weather and powerful geologic activity coincided earlier this week in Indonesia’s North Sulawesi province, where a volcanic eruption spewed lava and ash nearly two miles into the air. As the plume of ejected material filled the sky, it was hauntingly illuminated by a lightning storm.

On Wednesday, officials ordered nearby residents to evacuate over fears of yet another disaster—a tsunami, which could occur if part of the volcano collapses into the ocean, writes CNN’s Kathleen Magramo.

Mount Ruang, a 2,400-foot volcano on Ruang Island in north-central Indonesia, erupted at least five times between Tuesday and Wednesday, and nearly 4,000 lightning strikes were recorded around its peak. The shocking combination of red-orange lava plumes and blazing lightning dominated the island’s skies, prompting the Center for Volcanology and Geological Disaster Mitigation, the Indonesian agency that tracks volcanic activity, to issue a Level IV alert, which is the highest level possible.

Officials warned people to stay out of the area within 3.6 miles of Mount Ruang, and nearly 12,000 residents stand to be impacted by flows and ash. So far, more than 800 people have temporarily relocated to neighboring Tagulandang Island, and no deaths or injuries have been reported.

By Thursday, the volcano was emitting a continuous plume of white-gray smoke that reached 1,600 feet above the mountain. Officials still called for vigilance, since the volcanic activity might not be over yet.

“The potential for further eruption is still high, so we need to remain alert,” Heruningtyas Desi Purnamasari, an agency official, said in a statement Thursday, per Reuters.

Footage of Ruang's Powerful Volcanic Eruption (2024)

Ruang’s eruptions came after hundreds of earthquakes shook the island. Located within the “Ring of Fire,” a 25,000-mile-long belt of volcanoes and fault lines, Indonesia has around 120 active volcanoes and is subject to extreme seismic activity. Natural disaster chain reactions have happened before, and officials expressed continued warnings that such a string of events could happen again.

In particular, scientists are concerned that Mount Ruang could partially collapse into the ocean and trigger a tsunami, as it did when it erupted in 1871. Mount Ruang is steep and produces particularly powerful explosions, heightening these apprehensions. In 2018, the Indonesian volcano Anak Krakatau erupted and partially collapsed in a landslide. Three-quarters of its volume fell into the sea, initiating a tsunami that killed more than 400 people on the islands of Java and Sumatra.

Now, those on Tagulandang Island—including Ruang residents who evacuated there—are being told to prepare for relocation to the city of Manado in Sulawesi, which is a six-hour boat journey away.

“Especially those who live near the coast should be aware of the potential for incandescent rocks to erupt, hot clouds and tsunami waves that could be triggered by the collapse of a volcanic body into the sea,” Abdul Muhari, a spokesperson for the National Disaster Mitigation Agency, tells Gracey Wakary and Edna Tarigan of the Associated Press (AP).

Falling rocks, ash and smoke have also had an impact on travel in the wider region.

“We have to close flight operations at Sam Ratulangi Airport due to the spread of volcanic ash, which could endanger flight safety,” Ambar Suryoko, head of the regional airport authority, tells the AP.

Mount Ruang, taken on Friday morning.
Mount Ruang on Friday morning. At least one regional airport has grounded all flights due to the dispersion of ash and smoke resulting from the mountain's eruptions this week.  PVMBG-BG-KESDM

Other countries, including Australia, are tracking how the dispersion of ash may affect their flights. The smoke reached around 70,000 feet into the atmosphere.

The island’s volcanic lightning has largely subsided as the eruptions have slowed, though it’s an uncommon phenomenon that continues to puzzle and intrigue researchers. As of 2015, eruptions accompanied by lightning have been observed 400 times across 152 volcanoes, reports Forbes James Farrell.

The 2022 eruption of Tonga’s Hunga Tonga-Hunga Ha’apai volcano prompted the most intense lightning rates ever recorded, producing up to 2,600 flashes per minute, according to a study published last year.

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