74,000-Year-Old Eruption Didn’t End Toba’s Danger, Study Finds

KEMETIC MINDS
Extreme Earth Changes Watch — Daily Report — August 23, 2026

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Good morning — today’s watch is led by new research showing that Indonesia’s Toba supervolcano remained capable of eruptions for thousands of years after its 74,000-year-old super-eruption, a finding with direct implications for how scientists assess long-dormant calderas ^[1]. On the ground, sinkholes drew emergency attention in Tucson, Arizona, and Bogo City, Philippines, while the U.S. Geological Survey logged an earthquake in western North Carolina ^[2][3][4].

Key Takeaways

• New dating of post-eruption lava domes shows Toba’s magma system stayed capable of erupting for thousands of years after its Youngest Toba Tuff super-eruption about 74,000 years ago ^[1].
• Emergency repairs are slated to begin next week on Tucson’s 10th Avenue, where a collapsed roadway exposed a bridge structure south of Interstate 10 ^[2].
• Philippine geologists inspected a roughly 15-meter ground opening in Bogo City, Cebu, but have not yet released findings on its cause or extent ^[3].
• The USGS reported an earthquake in Haywood County, North Carolina, on Saturday morning; the available coverage did not specify a magnitude ^[4].
• A new explainer warns that a Carrington-level solar storm today could knock out power grids for months ^[4].

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1. Indonesia: Toba Supervolcano Stayed Active for Millennia After Mega-Eruption

An international team involving Curtin University, Oregon State University, Heidelberg University and the Geological Agency of Indonesia examined how the Toba caldera behaved after the Youngest Toba Tuff eruption, which expelled at least 2,800 cubic kilometers of rhyolite magma about 74,000 years ago ^[1].

The work focused on “resurgence” — the uplift and renewed volcanic activity that follows a collapsed caldera’s adjustment after a major eruption. Dating of three post-eruption lava domes using argon in feldspar and helium in zircon showed that magma beneath the caldera remained capable of driving eruptions for thousands of years, even after parts of the system had cooled into solid rock ^[1].

Notably, some later eruptions pushed mostly solidified volcanic material to the surface, showing that liquid magma is not always required for renewed activity. That suggests scientists may need to look beyond underground pools of molten rock when assessing long-term hazards at large calderas such as Yellowstone and Campi Flegrei, which can remain restless with gas emissions, earthquakes and structural changes ^[1].

See the full report on the Toba study from Yahoo News.

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2. Tucson, Arizona: Sinkhole Exposes Bridge Structure on 10th Avenue

A sinkhole opened on 10th Avenue near Julian Wash, between 40th Street and 41st Street south of Interstate 10, revealing the bridge structure underneath and prompting emergency repairs ^[2].

The Tucson Department of Transportation and Mobility said contractors working for the city will begin fixing the damaged roadway next week. The department classified the work as emergency repairs due to the exposed bridge structure ^[2].

Read KVOA’s coverage of the Tucson sinkhole.

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3. Bogo City, Philippines: Geologists Assess 15-Meter Ground Opening

A technical team from the Mines and Geosciences Bureau (MGB) inspected a ground opening in Purok Indilicio, Barangay Guadalupe, Bogo City, Cebu, on Saturday, August 22, joined by personnel from the city disaster office and barangay officials ^[3].

The city government earlier estimated the opening at around 15 meters in extent, but stressed that the initial observation was not a final geological determination that the feature is a sinkhole. As of Sunday, August 23, the MGB had not yet released findings on its cause, depth, underground extent or the condition of the surrounding ground ^[3].

The area remains cordoned off, with the City Disaster Risk Reduction and Management Office monitoring the site and residents urged not to approach or enter the restricted zone ^[3].

Follow the Cebu Daily News update on the Bogo City opening.

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4. Western North Carolina: USGS Logs Earthquake in Haywood County

The United States Geological Survey reported an earthquake in Haywood County on Saturday morning, August 22 ^[4]. The coverage that reached this roundup did not include a magnitude, depth or time, so no further details are reported here.

See MSN’s report on the Haywood County earthquake.

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5. Space Weather: Revisiting the Carrington-Level Scenario

A new explainer notes that the Sun occasionally hurls enormous clouds of charged particles toward Earth, and that the most extreme of these can scramble the technology modern life depends on ^[4].

The report describes the largest such event ever recorded and warns that a Carrington-level storm today could knock out power grids for months ^[4].

Read the Carrington-level solar storm explainer on MSN.

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What Scientists Are Saying

“Gaining an understanding of those lengthy dormant periods will determine what we look for in young active supervolcanoes to help us predict future eruptions,” said Associate Professor Martin Danišík of Curtin University’s John de Laeter Centre ^[1].

The Toba team’s matching argon and zircon-helium ages near 74,000 years fit the rapid cooling expected after a catastrophic eruption, while the later, mostly solidified lava domes indicate that hazard monitoring should look beyond underground pools of molten rock ^[1].

In the Philippines, the MGB is conducting the geological assessment and is expected to provide technical recommendations, with the city government monitoring through the CDRRMO in the meantime ^[3]. In Tucson, the transportation department classified the roadway failure as an emergency repair because of the exposed bridge structure ^[2].

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How To Track These Events

All of these phenomena are monitored in real time by public agencies. The USGS earthquake monitoring page publishes continuous seismic notifications; NOAA’s weather and space weather products cover the storms that reach Earth; and the Smithsonian Global Volcanism Program’s weekly activity reports track erupting and restless volcanoes worldwide. All are free and public.

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References

1. Yahoo. (2026, August 22). Ancient Toba eruption reveals a supervolcano can stay dangerous for thousands of years. https://www.yahoo.com/news/science/articles/ancient-toba-eruption-reveals-supervolcano-115100993.html ↩a ↩b ↩c ↩d ↩e ↩f ↩g
2. KVOA. (2026, August 22). Sinkhole opens on 10th Ave near Julian Wash in Tucson. https://www.kvoa.com/news/nextdoor/sinkhole-opens-on-10th-ave-near-julian-wash-in-tucson/article_1082927d-9957-4bd0-bd5a-e8cc80ca1a26.html ↩a ↩b ↩c ↩d ↩e
3. Cebu Daily News. (2026, August 23). Sinkhole in Bogo City? MGB investigates, findings awaited. https://cebudailynews.inquirer.net/759992/mgb-inspects-reported-sinkhole-in-bogo-city-findings-awaited ↩a ↩b ↩c ↩d ↩e ↩f
4. MSN. (2026, August 22). USGS reports earthquake in western North Carolina. https://www.msn.com/en-us/news/other/usgs-reports-earthquake-in-western-north-carolina/ar-AA2aI55q ↩a ↩b ↩c ↩d ↩e ↩f

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