Ten Dormant Volcanoes That Could Still Reshape Our World
Dormant ≠ Safe
Silence deceives. In April 1815, Mount Tambora ended roughly a thousand years of calm and pushed 1816 into the “Year Without a Summer.” Snow in June across New England; failed European harvests; migration and hunger. The message endures: dormancy signals a pause, not extinction. Today we deploy GPS, InSAR, and multi-gas sensors—impressive, yes—yet coverage remains uneven, and escalation can compress from months to days. Sometimes… hours! Preparedness, therefore, is policy, not panic.
Ten Systems to Watch—Quiet Surfaces, Busy Interiors
1) Laguna del Maule, Chile
A silicic caldera where the ground rose by decimeters per year in the 2010s. Translation: shallow magma input at only a few kilometers depth. Tourism thrives around the lakes, but contingency drills must keep pace. Better rehearsed than surprised.
2) Uturuncu, Bolivia
A 6,000-meter sentinel with a ~70 km inflation footprint. Slow and steady. Not a red siren—an amber light. Evolved magma implies potential for ash-rich events if conduits open. Remote? Ash clouds travel.
3) Colli Albani (Alban Hills), Italy
Barely 20 km from Rome. Late 20th-century CO₂ bursts and hydrothermal anomalies confirmed active plumbing. Urban density multiplies consequence: even moderate unrest can disrupt rail hubs, ring roads, and utilities. Proximity is the hazard amplifier.
4) Campi Flegrei, Italy
West of Naples. Since 1950: bradyseism cycles, swarms, elevated gas flux. Last eruption—1538—was small; the exposure today is not. Even a modest ash event could strain hospitals, ports, and schools. Vigilance must be continuous.
5) Yellowstone, USA
Famous—and often misunderstood. Annual odds of a cataclysm are tiny, yet uplift–subsidence pulses, microquakes, and vigorous hydrothermal activity show a living system. A small ash-producing episode would still rattle aviation and power across multiple states. Manageable? Yes. Ignorable? No.
6) Mount Fuji, Japan
Dormant since 1707–1708 (Hōei). Beautiful, photogenic, strategically sensitive. Ashfall scenarios for the Kantō plain—Tokyo and beyond—are routinely updated to protect rail arteries and airports. Aesthetic icon; operational challenge.
7) Long Valley Caldera, USA
Mammoth Lakes remembers the 1980s: intense swarms, CO₂ pockets, deformation. Caldera lesson: long repose does not equal retirement. Episodic reactivation remains plausible, therefore planning remains prudent.
8) Askja, Iceland
After the explosive 1875 event—decades of relative quiet. Recently: deformation and clustered quakes. In a rift environment, timelines can collapse. Weeks from tremor to eruption? Possible. Aviation managers take note.
9) Paektu (Baekdu), DPRK/China
Source of a colossal ~940 CE eruption. Uplift, unusual helium ratios, and warm springs hint at renewed recharge. Cross-border science is essential; ash ignores passports. Coordination is a safety tool.
10) Cumbre Vieja, La Palma, Spain
Long present in hazard studies; in 2021 it spoke plainly—lava, SO₂ spikes, mass evacuations, months of ash cleanup. A modern case study in rapid escalation. Lessons learned should not be forgotten.
Comparative Snapshot (indicative)
| Volcano (Country) | Last Significant Eruption | Primary Current Concern | Exposure |
| Campi Flegrei (IT) | 1538 | Ashfall, ground instability, gas | Very high (Naples metro) |
| Mount Fuji (JP) | 1707–1708 | Ashfall, lahars | Very high (Kantō region) |
| Yellowstone (US) | Holocene minor events | Ash, hydrothermal blasts | Moderate (regional) |
| Paektu/Baekdu (CN/DPRK) | ~940 CE | Tall ash columns, explosivity | Moderate–high (cross-border) |
| Laguna del Maule (CL) | Holocene | Rapid uplift, silicic blast | Low–moderate (rural/visitors) |
Note: Schematic overview for quick comparison; operational decisions must follow official observatory guidance.
Signals That Deserve Attention
What usually comes first? Swarms of shallow M1–M4 quakes; accelerating uplift recorded by GPS and InSAR; gas shifts—rising CO₂/SO₂ ratios, elevated ³He/⁴He; warming springs and crater lakes. None guarantees eruption. Yet converging lines of evidence demand action: clear alert levels, pre-staged evacuation routes, ash cleanup logistics, backup power for hospitals and data centers, alternative air corridors. Practice now; improvise less later.
Risk: Uneven—Manageable—Real
Hazard (what a volcano can do) × exposure (who and what is nearby) = risk. Hence Campi Flegrei and Fuji rank high largely due to people and infrastructure, while Askja’s remoteness reduces local impact but can still disrupt North Atlantic flights. Uturuncu? A slow-building narrative—on the watch list, not the panic list.
Conclusion—Vigilance Over Drama
Prediction to the day remains elusive. Prevention of chaos is attainable. With sustained monitoring, open data, and disciplined planning, societies can convert frightening uncertainty into structured resilience. Dormant—yes. Harmless—no. And that is precisely why we stay ready!