Major volcano eruption in 2026?
Short Answer
The market anticipates at least two major volcano eruptions in 2026, pricing this outcome at 71.0% despite expert analysis showing no specific trend toward VEI-4 events or a link to the strong 2026 El Niño. The model's probability for this outcome is 53.0%.
1. Market Behavior & Drivers
The market’s largest move, a 66.0 percentage point spike on September 22, was driven by a confluence of news and social media reports about widespread volcanic activity. This followed an earlier 49.0 point surge on September 17, which was caused by social media amplification of the Anak Krakatau eruption in Indonesia. A ScienceDaily report on the volcano's ash blast to near-stratospheric altitudes contributed to that initial spike. The real-world activity included hundreds of eruptions and an eruptive episode from September 4-6 that grounded over 2,000 flights.
The subsequent price collapse was driven by corrections. The market dropped 38.0 points on September 18 as traders repriced for the continued absence of a global-scale eruption. This downward move was reinforced by drops on September 19 and September 21, driven by social media accounts debunking viral misinformation. Fact-checking efforts highlighted false footage from a 2021 eruption and misleading claims about sulfur dioxide that had inflated the perceived risk. The market has trended downward overall.
- Since last update (~21d): The "At least 1" outcome's model-market edge flipped after the market's +47.0pp surge.
- The model-led "At least 2" probability increased by +16.8pp, compressing the edge.
- Market-led "At least 3" probability decreased by -13.0pp, compressing the edge.
- Overall confidence score increased by +1.0pp since the prior report.
- Probability for one or more major eruptions lacks specific scientific basis or volcanic trend.
- Historical VEI-4+ eruption frequency is stable; volcanic agencies do not forecast specific magnitudes.
Who Wins and Why
| Outcome | Market | Model | Why |
|---|---|---|---|
| At least 3 | 9.0% | 5.2% | Expert analysis shows no demonstrated link between the 2026 El Niño and major eruption probability. |
| At least 1 | 82.0% | 67.4% | Expert analysis indicates no current trend toward a VEI-4 eruption in 2026, despite general activity. |
| At least 2 | 71.0% | 53.0% | No specific volcanoes are trending toward a VEI-4 eruption in 2026, according to expert analysis. |
Current Context
Current volcanic activity remains elevated, though not catastrophic. Indonesia’s Anak Krakatau reached Level III (Alert) on July 2, 2026, recording 224 eruptions through September 3, followed by a 25-hour eruptive episode from September 4-6 with lava flows [1][2]. This early-September activity disrupted Indonesian aviation, grounding over 2,000 flights and stranding approximately 270,000 passengers, with ash plumes reaching 6,000 m over Java and 15,000 m over Sumatra/Banten [3]. By September 21, Anak Krakatau was lowered to Level II due to declining activity and deformation; authorities maintained a 2 km exclusion and reported no tsunami link [1][2]. Separately, Mount Semeru remained at Alert Level III on September 22, erupting again at 13:11 local time. MAGMA Indonesia reported 1,842 Semeru eruptions and 4,747 nationwide eruptions in 2026 to date, but these counts are not equivalent to VEI-4 or VEI-6 events [4]. Chile’s Nevados de Chillán also erupted on September 18, producing a 380 m ash-and-rock plume for 45-50 minutes with no reported damage, maintaining a yellow alert and a 1-km exclusion zone [5]. An NWS Alaska ash advisory on September 11 reported no identifiable ash from Shishaldin and no detected eruption, which indicates that not all advisories confirm major eruptions [6]. Volcanic hazards include local ashfall, visibility reduction, aviation disruption, lahars, and marine debris; substantial climate forcing requires sufficiently large explosive stratospheric injections [7][8][9].
Prediction markets price a VEI-6 eruption in 2026 as unlikely. Available snapshots for a 2026 VEI-6 or higher natural eruption show probabilities around 4-10% Yes, or 90-96% No, according to Polymarket-derived reporting, Lines, and Parity data [10][11][12]. These contracts typically resolve based on Smithsonian Global Volcanism Program data after the year ends [10][11][12]. The definition of a "major eruption" is ambiguous; while a VEI-6 event is priced low, a separate Kalshi contract asks whether at least one VEI-4 eruption begins in 2026, and an earlier April analysis from Lines/Polymarket placed the probability of exactly one VEI-4-or-larger eruption at 44-45% [13][14].
Extreme El Niño conditions drive significant compound climate risk in 2026. Climatologist Zeke Hausfather reported an exceptionally strong 2026 El Niño, with the tropical Pacific sea-surface-temperature anomaly tying the 2015-16 event at 3.07°C [15]. Experts link this to drought, wildfire, heavier rainfall, heat, and food-security risks [15][16]. The United Nations World Food Programme estimates El Niño-related disruption could push at least 49 million additional people into acute food insecurity by late 2027, while Goldman Sachs analysts estimated global food-commodity prices could rise over 15% [16]. Climate Central counted 12 U.S. billion-dollar weather and climate disasters from January-June 2026, causing at least $31.9 billion in damage and 183 deaths; severe storms accounted for eight events, ranking fifth-highest for that period since 1980 [17]. Munich Re noted record-breaking heatwaves in the first half of 2026, including 41.8°C in Möckern, Germany; Chief Climate Scientist Tobias Grimm warned that continued warming combined with a potential "Super El Niño" is a dangerous mix [18]. A World Weather Attribution assessment of Nepal's August 26 flood disaster found that long-term warming and changing precipitation reduced slope stability, exceeding existing risk-reduction limits [19]. The evidence as of September 22 indicates elevated volcanic activity, but no cited source confirms a globally catastrophic VEI-6+ eruption; the strongest near-term natural disaster signal is compound climate risk from extreme El Niño conditions and related weather events [1][5][4][15][16][17][19][18][10][11].
Sources (19)
- 1Mount Anak Krakatau activity status lowered to Level II: Authority - ANTARA News Jawa Timurjatim.antaranews.com
- 2Kementerian ESDM RI - Media Center - News Archives - Aktivitas Anak Krakatau Menurun, Badan Geologi Turunkan Status dari Siaga Menjadi Waspadaesdm.go.id
- 3Indonesia airports reopen after volcano eruption leaves... - BBCbbc.com
- 4Mount Semeru Erupted Again This Afternoon (Tuesday, 22 September 2026)databoks.katadata.co.id
- 5"Came for Skiing, Nearly Faced Disaster"... Shocking 380m Black Volcanic Plume Erupts - The Asia Business Dailyasiae.co.kr
- 6Volcanic Ash Advisoryweather.gov
- 7Stratospheric Aerosol Observations and Modelingevents.ecmwf.int
- 8Maritime Impacts of Volcanic Eruptions: A Guide for the Prudent Marinerocean.weather.gov
- 9Volcanic hazards, volcano monitoring, and communications protocolsweather.gov
- 10Major volcano eruption (VEI ≥6) in 2026 90% No · Polymarketexplorer.struct.to
- 11VEI-6 Eruption in 2026: Market Holds at Nine Percent | Lines.comlines.com
- 12Major volcano eruption (VEI ≥6) in 2026? | Paritypredictparity.com
- 13Major volcano eruption this year? Odds & Predictions 2026 - Kalshikalshi.com
- 14VEI-4 Eruption Count 2026: One Event at 45% - Lines.comlines.com
- 15El Niño weather pattern enters record territory: Scientistphys.org
- 16Worsening El Nino threatens Asia with drought, potentially raising food prices globallyphys.org
- 17Mid-2026 Update: U.S. Billion-Dollar Weather and Climate Disastersclimatecentral.org
- 18Lower losses, growing risks: the natural disaster review for the first...munichre.com
- 19Climate Change Intensified Nepal’s Catastrophic Langtang Flood, WWA Study Findsdowntoearth.org.in
2. Price Chart
Historical Price (Probability)
Outcome probability
Date
3. Significant Price Movements
Notable price changes detected in the chart, along with research into what caused each movement.
Outcome: At least 2
📈 September 22, 2026: 66.0pp spike
Price increased from 5.0% to 71.0%
What happened: The primary driver of the 66.0 percentage point market spike on September 22, 2026, was a confluence of traditional news and social media reports detailing significant and widespread volcanic activity leading up to that date. While no single viral social media post from a key figure caused the movement, the "geologypage" Facebook post announcing a "powerful eruption of Anak Krakatau" on September 5, 2026 [1], established one major event. Subsequently, traditional news and YouTube videos highlighted increased activity, such as Kīlauea's eruption changes on September 17 [2] and Santiaguito's elevated explosions on September 20 [3], culminating in a "Volcanic activity worldwide" report on September 21 listing numerous active volcanoes [4]. This aggregate information, disseminated rapidly, strongly suggested a higher probability of meeting the "At least 2" major eruption outcome. Social media platforms like Facebook and YouTube acted as contributing accelerants, amplifying these critical updates as they became available.
📉 September 19, 2026: 10.0pp drop
Price decreased from 29.0% to 19.0%
What happened: The 10.0 percentage point drop in the prediction market was primarily driven by the correction of widespread social media misinformation regarding volcanic activity. Viral narratives featuring false footage, traced to a 2021 eruption, and misleading claims about sulfur dioxide had amplified the perceived severity of Indonesia's Anak Krakatau eruption, which began September 4-5, 2026 [5][6][7][8]. As the September 19 outcome date approached, official assessments clarified the eruption's local, non-climate-altering impact, and fact-checks debunked these misleading social media claims [9][10][5][6][7]. This dissipation of inflated perceptions, fueled by the debunking of earlier social media narratives, led to a downward adjustment in the market's assessment of "At least 2" major eruptions. Social media, through its initial amplification of misinformation and its subsequent correction, was a primary driver.
📉 September 18, 2026: 38.0pp drop
Price decreased from 67.0% to 29.0%
What happened: The 38.0 percentage point drop in the "Major volcano eruption in 2026?" market on September 18, 2026, was primarily driven by a market correction reflecting the continued absence of any global-scale major volcanic eruptions by that date [11][12][13][14][15][16]. Although Anak Krakatau erupted in early September, causing regional flight disruptions, its intense activity subsided by September 6 and it was not considered a major event with global climate implications [9][17][18]. By September 18, with no other globally significant volcanic activity occurring, the market reassessed the likelihood of reaching "at least 2" major eruptions in 2026. Social media was largely irrelevant to this price movement; the only specific social media activity on September 18 was a debunked rumor about a dam collapse at Kanlaon, unrelated to a major volcanic eruption [19].
📈 September 17, 2026: 49.0pp spike
Price increased from 18.0% to 67.0%
What happened: The primary driver of the price spike was widespread social media amplification of the Anak Krakatau eruption, which began in early September 2026 and caused significant flight disruptions and closures [8][20][21]. A ScienceDaily report on September 17, 2026, detailing Anak Krakatau's ash blast to nearly 10 miles high, likely coincided with renewed social media attention and a viral narrative [22][7]. This circulation, despite including fact-checked AI-generated videos, significantly heightened public perception of ongoing major volcanic activity, influencing the market [7][23]. Social media served as a primary driver, accelerating and amplifying the impact of both real news and misinformation.
Outcome: At least 3
📉 September 21, 2026: 18.0pp drop
Price decreased from 27.0% to 9.0%
What happened: The 18.0 percentage point drop was primarily driven by social media activity debunking viral misinformation surrounding the Anak Krakatau eruption in September 2026 [5][24][25][26]. Fact-checking efforts by accounts such as AFP Fact Check highlighted misleading videos, which falsely depicted residents fleeing or misrepresented old footage as current Indonesian volcanic activity [5][24][25][26]. This widespread correction of exaggerated claims on social media likely coincided with the price movement, reducing the perceived likelihood of "at least 3" major eruptions and clarifying the actual severity of volcanic events. Social media was a primary driver, rectifying an inflated public perception of risk.
Sources (26)
- 1facebook.com
- 2youtube.com
- 3youtube.com
- 4volcanodiscovery.com
- 5Fact Check: Misleading Video Claims Residents Fleeing Anak Krakatau Eruption - News En.tempo.coen.tempo.co
- 6False Claims: Indonesia Volcano Gases Threaten Malaysia - Newsy Todaynewsy-today.com
- 7How Media Is Fueling Misinformation About the Recent Indonesian Volcanic Eruption | Offbeat Concernsoffbeatconcerns.com
- 8Indonesia's Anak Krakatau eruption halts flights, schools, fishing | Reutersreuters.com
- 9Anak Krakatau Rumbles Again - NASA Sciencescience.nasa.gov
- 10Why Anak Krakatau’s Eruption Is Unlikely To Cool the Planet — What Scientists Say - CRBC Newscrbcnews.com
- 11Volcanic Ash Advisoryweather.gov
- 12Volcanic Ash Advisories and Graphicsweather.gov
- 13Anchorage Volcanic Ash Advisory Centerweather.gov
- 14Anchorage Volcanic Ash Advisory Centerpreview.weather.gov
- 15National Weather Serviceforecast.weather.gov
- 16National Weather Serviceforecast.weather.gov
- 17Volcanic Ash and Ashfallweather.gov
- 18Stratospheric Aerosol Observations and Modelingevents.ecmwf.int
- 19OCD-NIR Debunks Kanlaon 'Dam Collapse' Claims, Sets Aerial Survey - Philippines News Gazettephilippinesnewsgazette.com
- 20Indonesia volcano eruption leaves 270,000 stranded as airports extend closurebbc.com
- 21Volcano eruption in Indonesia leaves 170,000 travellers stranded as eight airports closed | Indonesia | The Guardiantheguardian.com
- 22Anak Krakatau blasts ash nearly 10 miles high - ScienceDailysciencedaily.com
- 23Volcano Erupts on Camera: Is This Real Anak Krakatau Footage, or...srilanka.factcrescendo.com
- 24Old Guatemala volcano footage misrepresented as Mount Anak...factcheck.afp.com
- 25Indonesia's Mount Anak Krakatau erupted multiple times... - Facebookfacebook.com
- 26Indonesia's Mount Anak Krakatau erupted multiple times... - Facebookfacebook.com
4. Market Data
Contract Snapshot
A "YES" resolution is triggered if at least one major volcano eruption occurs by December 31, 2026. Conversely, a "NO" resolution occurs if no major volcano eruption happens within this period. The latest possible date for payout is June 29, 2027, but the contract content does not explicitly define what constitutes a "major volcano eruption" or specify its reference source.
Available Contracts
Market options and current pricing
| Outcome bucket | Yes (price) | No (price) | Last trade probability |
|---|---|---|---|
| At least 1 | $0.50 | $0.76 | 82% |
| At least 2 | $0.10 | $0.94 | 71% |
| At least 3 | $0.09 | $0.96 | 9% |
Market Discussion
Prediction markets and analyses price the probability of a VEI 6+ eruption in 2026 as low, typically between 7.9% and 9.5% "Yes," attributing this to historical frequency and current monitoring [1]. Although various volcanoes have shown activity in 2026, including Nevados de Chillán with a 380-meter plume on September 18, Anak Krakatau with activity lowered on September 21, and multiple eruptions reported for Semeru and Ibu on September 22, these events are not identified as major VEI 6+ eruptions [2]. Scientific forecasting research published August 26, 2026, has focused on improving data-driven eruption forecasts for existing volcanoes, but does not offer a specific prediction for a major event in 2026 [3].
5. Trust Index
Order book is critically thin.
Primary risk· Trade quality
How it adds up
Integrity80% of score80Good
Trade quality20% of score21Avoid
Includes the cost to trade: a $1,000 order can't be filled here because the order book is too thin.
Trust score68Caution
Weighted blend with hard caps — a critically weak safety pillar, or a severe trading anomaly, caps the total regardless of the rest. Full methodology · About the Trust Index
Trust profile
Integrity4 screens run · 6 don't apply
6. What is the historical annual frequency of VEI-4 or higher eruptions, according to data from the Smithsonian's Global Volcanism Program?
| Average VEI-4+ eruptions (1960-2025) | 1.1 eruptions per year [1] |
|---|---|
| VEI >=4 frequency trend (over century) | Remained impressively constant [2] |
| VEI-4+ eruptions in 2025 | 1 [1] |
The historical frequency of VEI-4 or higher eruptions shows long-term stability. Data from the Smithsonian's Global Volcanism Program (GVP) indicates that the average annual frequency of such eruptions was approximately 1.1 per year between 1960 and 2025 [1]. The GVP further notes that the frequency of larger eruptions, specifically those rated VEI >=4 and producing at least 0.1 km³ of tephra or magma, has consistently remained stable for over a century [2].
Despite long-term stability, annual VEI-4+ eruption counts fluctuate year-to-year. While the overall long-term frequency is constant, annual sums for VEI-4, VEI-5, and VEI-6 eruptions have varied during the 1960–2025 period for completed years [1]. Recent GVP annual counts for VEI-4 or higher events include two in 2020, three in 2021, one in 2022, two in 2023, one in 2024, and one in 2025 [1]. The GVP's data for 2026 was incomplete as of its update dated March 31, 2026 [1].
7. What scientific evidence links the strong 2026 El Niño event to an increased probability of major eruptions along the Pacific Ring of Fire?
| El Niño-Eruption Link | No demonstrated link [1][2] |
|---|---|
| El Niño 2026-27 Strength Forecast | More than 90% odds of a very strong event in fall/winter 2026–27 [3] |
| Major Eruption Probability | Approximately none or unquantified [4][1][5][6] |
No scientific evidence links the strong 2026 El Niño to increased major eruptions. Scientific sources do not demonstrate a direct link between a strong El Niño event, such as the one forecast for 2026, and an increased probability of major eruptions along the Pacific Ring of Fire [1][2]. The retrieved sources contain no statistically grounded evidence that El Niño increases the frequency or magnitude of major eruptions, and no source provides an eruption probability conditional on the 2026 El Niño forecast [3][7][8][2][9]. NOAA’s PMEL FAQ states that the El Niño-Southern Oscillation (ENSO) is determined by coupled tropical-Pacific ocean–atmosphere dynamics, with no known connection to volcanic forcing, which serves as evidence against treating ENSO as a volcano predictor [1].
A strong 2026 El Niño is forecast, but does not increase eruption probability. NOAA’s September 10 diagnostic reported Niño-3.4 at +1.8°C and eastern-index anomalies up to +3.4°C, with more than 90% odds of a very strong event in fall/winter 2026–27 and 75% odds of a historic October–December event at or above +2.5°C RONI [3]. However, the Climate Prediction Center’s (CPC) official ENSO strength page explicitly warns that stronger ENSO events do not necessarily produce proportionally stronger impacts and never guarantee a particular outcome; its listed impacts concern climate anomalies, not volcanic eruptions [8][10]. Therefore, even granting a strong 2026 El Niño, the scientifically defensible update to the probability of a major Pacific Ring of Fire eruption is approximately none or unquantified [4][1][5][6]. Volcanic eruption risk should instead be monitored through volcano observatories and aviation-volcanic advisories, using signs such as unrest, ash-producing activity, and significant behavioral change [2][9].
Sources (10)
- 1FAQs | El Nino Theme Page - A comprehensive Resourcepmel.noaa.gov
- 2Volcanic hazards, volcano monitoring, and communications protocolsweather.gov
- 3Climate Prediction Center: ENSO Diagnostic Discussioncpc.ncep.noaa.gov
- 4Can volcanic eruptions cause El Niño? Maybe, maybe not - Climateclimate.gov
- 5Major volcano eruption this year? Odds & Predictions 2026 - Kalshikalshi.com
- 6How Many Major Volcano Eruptions Will There Be This Year?next.io
- 7[PDF] ENSO: Recent Evolution, Current Status and Predictionscpc.ncep.noaa.gov
- 8Official NOAA CPC ENSO Strength Probabilitiescpc.ncep.noaa.gov
- 9Pacific Region Volcanoes & Hazards to Aviationweather.gov
- 10Enso.htmlcpc.ncep.noaa.gov
8. How does the current volcanic activity of Anak Krakatau compare to Mount Semeru regarding the potential for a major VEI-4+ eruption in 2026?
| Anak Krakatau September Activity | 14 Strombolian eruptions and a 2.1-km ash plume [1][2] |
|---|---|
| Mount Semeru 2026 Eruption Count | 1,813 eruptions by September 15 [3][4] |
| Documented VEI-4+ Eruption | None for either volcano in cited reports [2][3] |
Predicting a major VEI-4+ eruption for 2026 lacks current scientific basis. The Alert Level 3 status for both Anak Krakatau and Mount Semeru serves as an operational hazard indicator rather than a specific forecast of explosivity or a probability for such an event [2][3][5]. As of September 22, 2026, Volcanic Ash Advisories from NWS/VAAC monitoring systems do not indicate an immediate risk or an imminent major VEI-4+ eruption for either volcano [6][7][8][9][10]. These monitoring systems primarily provide warnings for aviation safety and general situational awareness, rather than long-range predictions of specific eruption magnitudes [9][10][11]. Furthermore, the available reports do not document a VEI-4+ eruption at either volcano [2][3].
Anak Krakatau shows recent intensified activity, suggesting potential for escalation. Its current activity appears more concerning for near-term escalation due to a recent intensification into a new eruptive phase. PVMBG reported activity intensifying in June, followed by 14 Strombolian eruptions and a 2.1-kilometer-above-summit ash plume in September [1][2]. Anak Krakatau maintained Alert Level 3 through September 16 [1][2].
Mount Semeru exhibits persistent daily activity with a long-term eruptive pattern. This volcano appears at least as credible for ongoing eruption likelihood, characterized by consistent daily activity and an established persistent eruptive pattern [2][3][5]. PVMBG reported daily eruptive events between September 10 and 16, 2026, producing ash plumes ranging from 200 to 1,000 meters, while maintaining Alert Level 3 [3][4]. Separately, 1,813 Semeru eruptions were recorded in 2026 by September 15, though this count is not a Volcanic Explosivity Index (VEI) measure [3][4].
Sources (11)
- 1Krakatau - Smithsonian Institution | Global Volcanism Programvolcano.si.edu
- 2Global Volcanism Program | Volcanic Activity Report on Krakatau (Indonesia) — 10 September-16 September 2026volcano.si.edu
- 3Global Volcanism Program | Volcanic Activity Report on Semeru (Indonesia) — 10 September-16 September 2026volcano.si.edu
- 4Alert! Mount Semeru Erupted Again Early This Morning (Tuesday, 15...databoks.katadata.co.id
- 5Semeru - Smithsonian Institution | Global Volcanism Programvolcano.si.edu
- 6Volcanic Ash Advisories and Graphicsweather.gov
- 7Anchorage Volcanic Ash Advisory Centerweather.gov
- 8Volcanic Ash Advisory Centersweather.gov
- 9Volcanic hazards, volcano monitoring, and communications protocolsweather.gov
- 10Pacific Region Volcanoes & Hazards to Aviationweather.gov
- 11Maritime Impacts of Volcanic Eruptions: A Guide for the Prudent Marinerocean.weather.gov
9. What is the typical timeframe and methodology used by the Smithsonian's Global Volcanism Program to assign a final VEI rating to an eruption after it occurs in 2026?
| Preliminary VEI Characterization | Days to roughly a week [1][2][3][4] |
|---|---|
| VEI Volume Increase | ~Tenfold increase per interval [5][6] |
| Market Resolution Date | 29 June 2027 [7] |
The Global Volcanism Program (GVP) does not have a fixed VEI assignment timeline. The GVP does not specify a universal timeframe for assigning a final Volcanic Explosivity Index (VEI) rating to an eruption. Preliminary characterization is typically provided within days to roughly a week, while a more stable VEI commonly appears in the GVP database after additional evidence and review over weeks to months [1][2][3][4]. Although the GVP produces rapid daily and weekly reporting, weekly information is labeled as preliminary and subject to change. Carefully reviewed Bulletin reports cover longer periods, and the program compiles reports and studies into its eruption database over daily, weekly, and multi-month timescales [1][2][4]. For unusually complex eruptions, the process to assign a stable VEI can extend beyond typical timeframes [1][2][3][4]. The resolution date of June 29, 2027, for a 2026 eruption allows ample time for GVP revisions [7].
The Volcanic Explosivity Index is a logarithmic, volume-based scale. The VEI methodology is logarithmic and primarily volume-based, with each interval generally representing approximately a tenfold increase in explosive ejecta [5][6]. Plume height and qualitative descriptors provide supporting evidence for the rating [5][6]. For instance, the USGS illustrates VEI 4 near 0.1 km³ of tephra, VEI 5 near 1 km³, and VEI 6 near 10 km³, though these figures are subject to uncertainty [5][6]. GVP database records can represent an eruptive period lasting years by its most energetic phase or highest VEI [8][7].
Sources (8)
- 1Smithsonian Institution - Global Volcanism Program: Worldwide...volcano.si.edu
- 2https://volcano.si.edu/reports%5Fweekly.cfmvolcano.si.edu
- 3https://volcano.si.edu/reports%5Fweekly.cfm?weekstart=20250917volcano.si.edu
- 4https://volcano.si.edu/index.cfm/world/reports_weekly.cfmvolcano.si.edu
- 5Database Search - Eruptions - Global Volcanism Programvolcano.si.edu
- 6The Volcanic Explosivity Index: A tool for comparing the sizes of...usgs.gov
- 7Major volcano eruption in 2026? - Kalshi Odds | CoinRithmcoinrithm.com
- 8Global time-size distribution of volcanic eruptions on Earth - Naturenature.com
10. What specific seismic or geological precursors would prompt agencies like the USGS or Indonesia's PVMBG to forecast a VEI-4 or higher eruption for the remainder of 2026?
| VEI magnitude forecasting | Not done in advance (USGS, PVMBG) [1][2] |
|---|---|
| Universal precursors for VEI>=4 | None identified [2] |
| Short-term forecasting for VEI>=4 | Exceptionally difficult [3] |
Volcanic agencies do not forecast specific Volcanic Explosivity Index magnitudes. Monitoring organizations, including the USGS and Indonesia's PVMBG, do not issue forecasts for precise Volcanic Explosivity Index (VEI) magnitudes, such as VEI-4 or higher, prior to an eruption [1][2]. This approach is adopted because no universal or explicit precursory signals definitively indicate an eruption of VEI-4 or greater [2].
Agencies monitor various precursory signals to assess eruption potential. Instead of forecasting specific VEI values, these agencies concentrate on identifying patterns of precursory unrest, which encompasses seismic activity, ground deformation, gas emissions, and thermal anomalies [1]. They also utilize a volcano's historical geological records to help evaluate the potential scale of future events [2]. Agencies communicate the likelihood of an imminent or ongoing hazardous eruption using tiered alert systems, such as a 'Warning' or 'Level IV' status [4]. This communication is based on escalating monitoring signals rather than a projected VEI [4]. Short-term forecasting for large eruptions, those classified as VEI 4 or higher, remains exceptionally challenging, as precursory signals can vary considerably and may stay ambiguous until an eruption has already commenced [3].
11. What Could Change the Odds
Key Catalysts
The market for a major VEI ">="6 eruption in 2026 shows Yes near 8–9.5% and No near 90.5–92.1% as of September 22, 2026, with no sourced evidence for such an event [1][2][3]. Kīlauea is the clearest near-term volcanic catalyst; on September 21, USGS said the summit could return within 1–2 days to pressurization levels associated with prior vent openings [4][5]. This could entail renewed activity at existing vents, reactivation of vents 1–6, or intrusion into another summit weakness; no strong seismic precursor is expected [4]. Kīlauea’s September 14–16 opening of six new vents disrupted prior fountaining-cycle models. USGS said forecast windows could no longer be modeled, and conditions remained favorable for renewed fountaining or changed eruptive activity [6]. The Kīlauea signal is locally important but not evidence of a VEI-6 scenario; the alert remains Watch and aviation Orange, and USGS describes the likely outcomes as summit vent or rift-zone activity [7][5][4]. Bullish repricing signals for a major eruption are official alert escalation, accelerating ground deformation, clustered/migrating earthquakes, sustained high ash columns, or an explicitly confirmed VEI-6 classification [8][3][5][4]. An ordinary effusive Kīlauea episode or moderate Indonesian ash event would typically be insufficient [8][3].
Activity at Anak Krakatau declined, leading Indonesia to lower its status from Level III/Siaga to Level II/Waspada on September 21 [9]. Smithsonian/USGS reports continued activity at Krakatau, Merapi, Sabancaya, and Semeru during September 10–16 [10][11][12][13]. The major-eruption market's settlement is based on the Smithsonian GVP’s finalized 2026 VEI-6 figure, with a March 31, 2027 finalization checkpoint [3]. For weather-related markets, a very strong El Niño event, with a greater than 90% chance of persisting through the Northern Hemisphere winter of 2026-27, heavily influences late 2026 climate and weather outlooks [14][15][16][17]. NOAA’s September 2026 Atlantic outlook forecasts a 75% probability of below-normal activity, with 7–13 named storms, 2–6 hurricanes, and up to 2 major hurricanes; this centers below the 1991–2020 averages [18][16][17]. Despite the below-normal base case, late-season risk is not zero; roughly 50% of seasonal activity normally occurs after September 10, and late-season systems can form closer to the U.S. where El Niño suppression is weaker [19]. Elevated September–October risk is present in the Gulf of Mexico, Caribbean, U.S. East Coast, and Central Pacific [20]. Regional climate outlooks also indicate persistent wildfire and drought risks in Deep South Texas, with a potential transition to wetter conditions in late September to October [21].
Key Dates & Catalysts
- Expiration: June 29, 2027
- Closes: June 29, 2027
Sources (21)
- 1https://polymarket.com/event/major-volcano-eruption-vei-6-in-2026polymarket.com
- 2Major volcano eruption (VEI ≥6) in 2026? | Paritypredictparity.com
- 3Major volcano eruption (VEI ≥6) in 2026? — Odds & Charts | Prescientprescient.markets
- 4USGS Volcano Notice - DOI-USGS-HVO-2026-09-21T18:34:00+00:00volcanoes.usgs.gov
- 5Kīlauea Status Report | U.S. Geological Surveyusgs.gov
- 6Volcano Watch — The ups and downs of episode forecasting using tilt data | U.S. Geological Surveyusgs.gov
- 7USGS Volcano Notice - DOI-USGS-HVO-2026-09-20T18:06:49+00:00volcanoes.usgs.gov
- 8VEI-6 Eruption in 2026: Market Holds at Nine Percent | Lines.comlines.com
- 9Kementerian ESDM RI - Media Center - News Archives - Aktivitas Anak Krakatau Menurun, Badan Geologi Turunkan Status dari Siaga Menjadi Waspadaesdm.go.id
- 10Global Volcanism Program | Volcanic Activity Report on Krakatau (Indonesia) — 10 September-16 September 2026volcano.si.edu
- 11Global Volcanism Program | Volcanic Activity Report on Merapi (Indonesia) — 10 September-16 September 2026volcano.si.edu
- 12Global Volcanism Program | Volcanic Activity Report on Sabancaya (Peru) — 10 September-16 September 2026volcano.si.edu
- 13Global Volcanism Program | Volcanic Activity Report on Semeru (Indonesia) — 10 September-16 September 2026volcano.si.edu
- 14Climate Prediction Center - Outlookscpc.ncep.noaa.gov
- 15ENSO: Recent Evolution,cpc.ncep.noaa.gov
- 16Climate Prediction Center - Atlantic Hurricane Outlookcpc.ncep.noaa.gov
- 17Climate Prediction Center - Atlantic Hurricane Outlookcpc.ncep.noaa.gov
- 18Climate Prediction Center - Atlantic Hurricane Outlookcpc.ncep.noaa.gov
- 19El Niño has broken Atlantic hurricanes. Now the season is breaking records | CNNcnn.com
- 20Mid-Season Update: 2026 Tropical Storm & Hurricane Outlook — North Atlantic, Northeast & Central Pacificsea.weathernews.com
- 21September-November (Autumn 2026) Outlook: Perspective for the Lower Rio Grande Valley/Deep S. Texas Regionweather.gov
