Which U.S. Volcanoes Are Most Likely to Erupt Next?

Explore the threat assessment, monitoring advances, and risk factors shaping which U.S. volcanoes may erupt soon.

By Medha deb

Created on Sep 27, 2025

Explore the threat assessment, monitoring advances, and risk factors shaping which U.S. volcanoes may erupt soon.

Which U.S. Volcanoes Are Likely to Erupt Next?

With over 170 active or young volcanoes in the United States, determining which ones pose the greatest threat is a vital question for scientists and the public alike. The combination of scientific threat assessments, evolving monitoring technology, and natural risk factors helps identify those volcanoes most likely to erupt in the near future. This article explores how volcanoes are ranked by eruption risk, the science of volcanic hazards, next-in-line volcanoes for eruption, and the advances in volcano monitoring shaping predictions today.

Understanding Volcanic Threat in the U.S.

The United States Geological Survey (USGS) maintains a detailed assessment of U.S. volcanoes through the National Volcano Early Warning System (NVEWS), which monitors and ranks volcanoes according to their eruption risk and threat level to communities and infrastructure. Not all volcanoes pose the same danger: a volcano’s risk depends on its eruptive style, proximity to people, and geologic setting.

Eruptive Style: Some volcanoes erupt explosively, spewing ash and lava, while others are less dramatic but still hazardous.
Location: Volcanoes near populated areas or critical infrastructure pose a higher threat.
Monitoring: The ability to detect early warning signs is crucial to mitigating risk.

The 2018 USGS Volcano Threat Assessment

In 2018, the USGS published an updated national volcanic threat assessment, ranking U.S. volcanoes by their threat level to life, property, and infrastructure. The assessment helps direct resources toward those volcanoes most in need of monitoring and risk mitigation.

How Scientists Assess Eruption Risk

Volcano threat assessments are based on historical eruption frequency, known hazards, population at risk, and current signs of volcanic unrest. Several scientific techniques help identify which volcanoes are likely to erupt next:

Seismic Monitoring: Detects earthquakes and tremors associated with rising magma.
Gas Emissions: Increases in gases like carbon dioxide and sulfur dioxide indicate fresh magma movement.
Ground Deformation: Swelling or sinking of the ground, measured by satellites or ground instruments, can precede eruptions.
Thermal Imaging: Reveals changes in heat output that may signal magma activity.
Vegetation Changes: Emerging research shows subtle greening of vegetation near volcanoes, detectable from space, may offer early clues to pending eruptions.

Top Threat U.S. Volcanoes: Who’s Next To Erupt?

While scores of U.S. volcanoes are considered potentially hazardous, several stand out for their recent activity, eruption history, and proximity to people. Here are the volcanoes experts most closely watch for signs of imminent eruption:

Mount St. Helens, Washington

Among the most infamous U.S. volcanoes, Mount St. Helens last erupted in 2008, following its cataclysmic 1980 explosion. It remains highly monitored due to its history of sudden, explosive eruptions and potential for renewed activity.

The volcano is closely tracked by seismic sensors, gas monitors, and satellite imaging.
Even minor eruptions can damage nearby infrastructure and trigger dangerous landslides or mudflows.

Kīlauea, Hawaii

A spectacularly active shield volcano, Kīlauea has erupted continuously for decades, with its 2018 event destroying hundreds of homes and changing the island’s landscape. Its ongoing activity makes it a top candidate for future eruptions.

Kīlauea’s eruptions are often less explosive, but lava flows travel far and fast.
It is highly instrumented, with continuous seismic, deformation, and gas monitoring.

Mount Rainier, Washington

Less known for eruption frequency but feared for disaster potential, Mount Rainier could trigger lethal mudflows (lahars) threatening thousands of downstream residents.

Mount Rainier hasn’t erupted in over a century, but scientists regard it as a high-threat volcano due to its massive glaciers and nearby population.
Its slopes are prone to landslides and lahars during eruptions or even without volcanic activity.

Volcano	State	Last Eruption	Main Hazards	Threat Rank (2018)
Mount St. Helens	WA	2008	Explosive eruptions, ashfall, landslides	Very High
Kīlauea	HI	2020 (ongoing)	Lava flows, gas emissions, earthquakes	Very High
Mount Rainier	WA	1894	Lahars, floods, ashfall	Very High
Redoubt Volcano	AK	2009	Ash plumes, lahars	Very High
Mount Shasta	CA	1786	Lahars, landslides, ashfall	Very High

Volcanoes Under Watch: Other Notable Risks

Mount Hood, Oregon: Last erupted in the 1700s, but its proximity to Portland makes it a high-threat candidate.
Mount Shasta, California: Large, potentially explosive; risk from lahars and pyroclastic flows.
Redoubt Volcano, Alaska: Responsible for major ash events affecting air travel.
Augustine Volcano, Alaska: Multiple eruptions in recent decades, close to shipping routes.
Mauna Loa, Hawaii: World’s most massive volcano; last erupted in 1984, closely watched for renewed activity.

What Makes a Volcano Next-In-Line?

Volcanoes most likely to erupt soon share several common elements:

Recent or ongoing seismic activity
Fresh or increasing gas emissions
Rapid ground deformation
Increased thermal activity
Historic patterns indicating periodic eruptions

The Role of Climate in Volcanic Hazards

Recent research finds that climate change and especially intensified rainfall can trigger hazardous volcanic events, including eruptions and catastrophic landslides. Heavy rainfall infiltrates volcanic slopes, potentially destabilizing them and providing water to fuel explosive volcanic reactions. This means warming-driven weather extremes increase volcano risks in places like the Pacific Northwest and Alaska.

Extreme rainfall can trigger dome explosions, flanks collapses, and increase lahar frequency.
Rainfall effects are notable at volcanoes like Mount St. Helens and Kīlauea, where water infiltration can influence magma movement and surface stability.
Climate change coupling requires updated hazard management and emergency planning in volcanic regions.

Scientific Advances: Early Warning Technologies

Emerging technologies are improving volcano forecasting and risk reduction:

Satellite Detection: NASA satellites can detect vegetation color changes (greening) caused by volcanic gas emissions, providing a new tool for early eruption detection.
Remote Gas Sensors: Monitor volcanic gases such as CO₂ and SO₂, offering signs of magma ascent.
Seismometer Networks: Dense arrays deliver real-time earthquake data to pinpoint magma movement.
Ground-Based Radar and GPS: Track ground deformation with high precision.

National Volcano Early Warning System (NVEWS)

The NVEWS initiative is designed so that monitored volcanoes receive attention commensurate with their threats. High-risk volcanoes are continually observed, while others are tracked by less frequent or remote sensing. The goal: provide rapid public alerts and support timely evacuation if unrest escalates.

Scientists use ground and satellite observations for comprehensive coverage.
Collaboration across federal, state, and academic partners ensures multi-disciplinary monitoring.

Living Near a Volcano: Risks and Mitigation

Nearly ten percent of the world’s population lives in volcanic hazard zones. While U.S. volcanoes seldom erupt with little warning, the greatest danger often arises from secondary hazards such as lahars, landslides, mudflows, and ash clouds, which can devastate communities miles from the eruption site.

Lahar Paths: Cities like Tacoma and Orting, Washington, lie in mapped lahar routes from Mount Rainier.
Ashfalls: Eruptions can blanket regions in abrasive ash, affecting air travel and water supplies.
Gas Emissions: The release of SO₂ and CO₂ can threaten health and disrupt agriculture.

Preparedness and Risk Reduction

Local governments conduct evacuation drills and maintain hazard maps.
Residents are urged to have emergency kits prepared and to heed official alerts.
Researchers work to improve eruption models and pinpoint precursors for faster warnings.

Frequently Asked Questions (FAQs)

Q: How do scientists know which volcano will erupt next?

A: Scientists monitor seismic signals, gas emissions, ground deformation, and historical activity to assess eruption likelihood. They focus resources on volcanoes showing signs of unrest or with past histories of sudden activity.

Q: Can volcanic eruptions be predicted accurately?

A: While scientists can often forecast likely eruptions days or weeks ahead, precise timing and magnitude remain difficult due to the complex nature of volcanic systems. Ongoing research seeks to refine predictions.

Q: What are the biggest dangers from U.S. volcanoes?

A: Key hazards include lava flows, explosive ash clouds, deadly mudflows (lahars), toxic gas emissions, and landslides. Impacts often extend many miles from the volcano itself.

Q: Are more volcanoes becoming active due to climate change?

A: Researchers have linked increasing rainfall and warming temperatures to destabilized volcanic regions, which may raise eruption or landslide risks in some areas.

Q: What should people living near volcanoes do?

A: Stay informed, participate in local evacuation planning, prepare emergency kits, and monitor official alerts during periods of volcanic unrest. Knowledge and preparedness are key to safety.

Key Takeaways

Only a fraction of U.S. volcanoes pose significant risk, focused in Alaska, Hawaii, Cascades, and California.
Mount St. Helens, Kīlauea, Mount Rainier, and Redoubt Volcano are among the best-monitored and highest-risk for future eruptions.
Advances in technology, from satellites to ground sensors, are improving early warning and risk reduction.
Volcanic hazards are shaped by both geologic activity and climate change, with rainfall a significant trigger in some regions.
Public awareness and scientific monitoring are essential to minimize the dangers posed by future eruptions.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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