# Will there be an at least 8.0 magnitude earthquake in California before 2028?

Before 2028

Updated: May 6, 2026

Category: Climate and Weather

HTML: /markets/climate-and-weather/will-there-be-an-at-least-8-0-magnitude-earthquake-in-california-before-2028/

## Short Answer

**Key takeaway.** Both the **model** and the **market** expect an at least 8.0 magnitude earthquake to occur in California before 2028, with no compelling evidence of mispricing.

## Key Claims (January 2026)

**- - UCERF3 estimates a 7% statewide chance of M8.0+ earthquake over 30 years.** - The chance of M8.0+ before 2028 is significantly smaller than **7%**.
- UCERF3 provides long-term forecasts, giving estimates over several decades.
- California faults are monitored in real-time for stress changes and deformation.
- Seismologists consider foreshocks potential precursory signs, not standalone predictors.

### Why This Matters (GEO)

- AI agents extract claims, not arguments.
- Improves citation probability in summaries and answer cards.
- Enables fact stitching across multiple sources.

## Executive Verdict

**Key takeaway.** **Model**'s **7.6%** **probability** (UCERF3 logic) is 8.4 points below the **market**'s **16%** price.

### Who Wins and Why

| Outcome | Market | Model | Why |
| --- | --- | --- | --- |
| Before 2028 | 16.0% | 7.6% | California's location on active fault lines makes major earthquakes a persistent, albeit rare, risk. |

## Model vs Market

- Model Probability: 7.6% (Yes)
- Market Probability: 16.0% (Yes)
- Yes refers to: Before 2028
- Edge: -8.4pp
- Expected Return: -52.5%
- R-Score: -0.84
- Total Volume: $6,084.18
- 24h Volume: $0
- Open Interest: $5,926.18

- Expiration: December 31, 2028

## Market Behavior & Price Dynamics

This market has traded in a stable, sideways pattern, establishing a clear range between 11.0% and 16.0%. These levels have acted as firm support and resistance, respectively. The price began at the 11.0% support level before making a single, decisive move up to 16.0%, where it has remained. The overall trend is flat, characterized by long periods of inactivity punctuated by this one significant price adjustment. The current price of 16.0% represents the market's all-time high.

The provided context, which centers on the long-term USGS forecast (a 7% chance over 30 years), helps frame the general risk but does not point to a specific event that would have caused the price to jump from 11% to 16%. This suggests the shift was not a reaction to new, publicly available scientific data. The most critical factor in this market is the extremely low trading volume, with only 70 contracts traded in total. This thin liquidity suggests that price movements are likely driven by a very small number of participants and do not reflect a broad consensus or strong market conviction. The current price of 16% indicates that the few active traders believe the probability of a major earthquake in this short timeframe is significantly higher than what a simple pro-rata calculation of the 30-year scientific forecast would imply.

## Contract Snapshot

This market resolves to "Yes" if an earthquake of at least 8.0 magnitude with an epicenter in California or its territorial waters occurs before December 31, 2028, as verified by USGS; otherwise, it resolves to "No." The market closes early if the event occurs, or by December 30, 2028, at 11:59 PM EST if the event does not happen. Insider trading by individuals with material, non-public information or those employed by Source Agencies is prohibited.

## Market Discussion

Probabilistic models from the U.S. Geological Survey (USGS) estimate approximately a 7.0% chance of an 8.0 magnitude earthquake in California over the next 30 years, with a 2019 estimate suggesting a "few percent" chance within a 10-year window [[^]](https://www.conservation.ca.gov/cgs/Pages/Earthquakes/UCERF3.aspx)[[^]](https://legacy.geog.ucsb.edu/new-long-term-earthquake-forecast-for-california/)[[^]](https://southern.scec.org/ucerf)[[^]](https://www.latimes.com/local/lanow/la-me-ln-chance-of-80-earthquake-in-california-rises-usgs-says-20150310-story.html)[[^]](https://www.govtech.com/recovery/Risk-8-Earthquake-California-Leaps.html)[[^]](https://www.quora.com/Will-California-have-8-0-earthquake-in-10-years). Experts consistently state that precise earthquake prediction is currently impossible, and only probabilistic forecasts exist, which indicate low odds for such an event before 2028, aligning with pricing on prediction markets [[^]](https://www.latimes.com/local/lanow/la-me-ln-chance-of-80-earthquake-in-california-rises-usgs-says-20150310-story.html)[[^]](https://www.quora.com/Will-California-have-8-0-earthquake-in-10-years)[[^]](https://www.youtube.com/watch?v=UptxVzgETfY)[[^]](https://www.coinbase.com/predictions/event/KXEARTHQUAKECALIFORNIA-27)[[^]](https://kalshi.com/markets/kxearthquakecalifornia/earthquake-in-california/kxearthquakecalifornia-27).

## Market Data

| Contract | Yes Bid | Yes Ask | Last Price | Volume | Open Interest |
| --- | --- | --- | --- | --- | --- |
| Before 2028 | 10% | 20% | 16% | $6,084.18 | $5,926.18 |

## According to the paleoseismic record, what is the average recurrence interval for M8.0+ ruptures on the San Andreas fault, and how does the current period compare to that historical baseline?

Mean Recurrence Wrightwood | ~105 years [[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf)[[^]](https://pubs.usgs.gov/publication/70024267) |
Mean Recurrence Pallett Creek | ~145 years [[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf)[[^]](https://pubs.usgs.gov/publication/70024267) |
Years since Fort Tejon (as of 2026-05-06) | ~169 years [[^]](https://www.earthquaketracker.org/faults/san-andreas) |

**San Andreas fault large rupture recurrence intervals vary by location**

San Andreas fault large rupture recurrence intervals vary by location. Paleoseismic studies show that recurrence baselines for significant events, typically M7.5 or greater, are not uniform across the entire fault, rather they are representative records for large events [[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf)[[^]](https://pubs.usgs.gov/publication/70024267). Over the past 1500 years, mean recurrence intervals have been approximately 105 years at Wrightwood and 145 years on average at Pallett Creek [[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf)[[^]](https://pubs.usgs.gov/publication/70024267). More recent analyses suggest that the recurrence intervals for large (M7.5+) events might range from 145 to 200 years [[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf)[[^]](https://pubs.usgs.gov/publication/70024267).

Current southern San Andreas quiescence exceeds historical mean intervals. As of May 6, 2026, the southern San Andreas segment has experienced a quiescent period longer than the paleoseismic mean intervals of 100 to 150 years [[^]](https://www.earthquaketracker.org/faults/san-andreas)[[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf). The last major rupture, the 1857 Fort Tejon event, occurred approximately 169 years ago [[^]](https://www.earthquaketracker.org/faults/san-andreas). This extended period indicates the fault is considered “overdue” when measured against average recurrence times at locations like Wrightwood and Pallett Creek, though it has not yet surpassed the complete observed range of historical intervals [[^]](https://www.earthquaketracker.org/faults/san-andreas)[[^]](https://rock.geosociety.org/net/gsatoday/archive/14/9/pdf/i1052-5173-14-9-4.pdf)[[^]](https://archives.datapages.com/data/pacific/data/067/067001/pdfs/81.pdf).

## How does the M8.0+ rupture potential before 2028 compare between the southern San Andreas Fault and the Cascadia Subduction Zone?

So. San Andreas Fault M>=8.0 probability (30 years) | about 7% [[^]](https://www.scec.org/ucerf)[[^]](https://en.wikipedia.org/wiki/UCERF3) |
Cascadia Subduction Zone M>=8 rupture probability (50 years, PNAS) | 15% [[^]](https://www.pnas.org/doi/10.1073/pnas.2424659122) |
Cascadia Subduction Zone M>=8.0 probability (50 years, USGS) | up to ~37% [[^]](https://en.wikipedia.org/wiki/Cascadia_subduction_zone)[[^]](https://www.usgs.gov/publications/earthquake-probabilities-and-hazards-us-pacific-northwest) |

**Direct comparisons for M8.0+ rupture potential before 2028 are unavailable**

Direct comparisons for M8.0+ rupture potential before 2028 are unavailable. Directly computed probabilities for M8.0+ ruptures specifically before 2028 are not available for either the southern San Andreas Fault or the Cascadia Subduction Zone within the retrieved research. Therefore, a direct comparison for this precise timeframe cannot be made based on the provided information, requiring any such assessment to infer relative likelihoods from published 30- or 50-year probabilities [[^]](https://en.wikipedia.org/wiki/UCERF3)[[^]](https://www.scec.org/ucerf)[[^]](https://www.pnas.org/doi/10.1073/pnas.2424659122)[[^]](https://en.wikipedia.org/wiki/Cascadia_subduction_zone).

Southern San Andreas Fault has a **7%** chance of M>=8.0 in 30 years. For the southern San Andreas Fault, materials from the Third Uniform California Earthquake Rupture Forecast (UCERF3) indicate that the likelihood of a California M>=8.0 earthquake within the next 30 years increased to approximately **7%**. The UCERF3 **model** also identifies this fault segment as the most probable source for a large earthquake [[^]](https://www.scec.org/ucerf)[[^]](https://en.wikipedia.org/wiki/UCERF3).

Cascadia Subduction Zone shows higher long-term M>=8.0 rupture probabilities. Regarding the Cascadia Subduction Zone, a 2025 paper published in PNAS reports a time-independent **probability** of an M>=8 rupture as **15%** within the next 50 years [[^]](https://www.pnas.org/doi/10.1073/pnas.2424659122). Other hazard interpretations from communications by the U.S. Geological Survey (USGS) and Pacific Northwest sources cite a broader range, indicating up to approximately **37%** for an M>=8.0 event within 50 years for Cascadia [[^]](https://en.wikipedia.org/wiki/Cascadia_subduction_zone)[[^]](https://www.usgs.gov/publications/earthquake-probabilities-and-hazards-us-pacific-northwest).

## What specific seismic precursors, such as foreshock sequences or aseismic slip, would seismologists from the USGS or Caltech consider critical indicators of an impending M8.0+ event?

Percentage of M4+ mainshocks with foreshocks | 72% (Caltech, 2008–2017 data) [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20190820-133631627) |
Median foreshock sequence duration | 16.6 days (Caltech, 2008–2017 data) [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20190820-133631627) |
Long-duration earthquake swarms with ultra-slow patterns | 53% (Caltech-linked research, 2008–2020 data) [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20210610-133645643) |

**Seismologists view foreshocks as potential precursory signs, not standalone predictors**

Seismologists view foreshocks as potential precursory signs, not standalone predictors. While considered useful for monitoring precursory activity, seismologists from the USGS and Caltech do not consider foreshocks guaranteed indicators of an impending M8.0+ event [[^]](https://www.usgs.gov/faqs/foreshocks-aftershocks-whats-difference)[[^]](https://www.usgs.gov/publications/intermediate-term-pre-earthquake-phenomena-california-1975-1986-and-preliminary)[[^]](https://www.usgs.gov/centers/mendenhall-research-fellowship-program/experimental-studies-aseismic-slip-earthquake). The USGS defines foreshocks as earthquakes that precede larger mainshocks in the same location, but they are specifically identified only after the larger mainshock has occurred [[^]](https://www.usgs.gov/faqs/foreshocks-aftershocks-whats-difference). Caltech research, analyzing data from 2008–2017 in southern California, revealed that **72%** of M4+ mainshocks were preceded by foreshock activity significantly elevated above local background levels. These sequences typically lasted from several days to weeks, with a median duration of 16.6 days [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20190820-133631627). Despite this, the USGS explicitly frames foreshocks as identifiable only after the mainshock, and discussions of intermediate-term phenomena emphasize probabilistic increased likelihood rather than certainty for prediction [[^]](https://www.usgs.gov/faqs/foreshocks-aftershocks-whats-difference)[[^]](https://www.usgs.gov/publications/intermediate-term-pre-earthquake-phenomena-california-1975-1986-and-preliminary)[[^]](https://www.usgs.gov/centers/mendenhall-research-fellowship-program/experimental-studies-aseismic-slip-earthquake).

Aseismic slip offers monitoring utility, but not guaranteed M8+ prediction. The USGS notes that active faulting frequently involves a combination of seismic and aseismic behavior, including episodic slow slip and tremor, as well as geodetically or observationally detectable aseismic slip occurring concurrently with foreshock activity [[^]](https://www.usgs.gov/centers/mendenhall-research-fellowship-program/experimental-studies-aseismic-slip-earthquake). The USGS suggests that aseismic deformation can be valuable for monitoring precursory activity [[^]](https://www.usgs.gov/centers/mendenhall-research-fellowship-program/experimental-studies-aseismic-slip-earthquake). For instance, a Caltech study inferred that aseismic slip persisted for more than two months following mainshocks, imposing stresses that helped trigger subsequent earthquakes [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20170418-081344017). Additionally, the USGS documented "intermediate-term" pre-earthquake signals in California from 1975–1986, which included the sudden appearance of earthquakes in previously inactive areas and described surface fault creep as a sensitive indicator of stress changes [[^]](https://www.usgs.gov/publications/intermediate-term-pre-earthquake-phenomena-california-1975-1986-and-preliminary). Caltech-linked research identified 92 long-duration earthquake swarms in southern California from 2008–2020, where **53%** showed ultra-slow diffusive patterns consistent with fluid injection processes, implying ongoing transient aseismic drivers [[^]](https://resolver.caltech.edu/CaltechAUTHORS:20210610-133645643). Nevertheless, these sources consistently describe aseismic deformation as potentially useful for monitoring, but not a standalone guaranteed indicator of an impending M8+ event [[^]](https://www.usgs.gov/centers/mendenhall-research-fellowship-program/experimental-studies-aseismic-slip-earthquake).

## What real-time monitoring data from sources like the USGS is available to assess stress changes or crustal deformation on California's major fault systems?

GPS data frequency | Daily and near real-time [[^]](https://earthquake.usgs.gov/monitoring/deformation/)[[^]](https://www.usgs.gov/programs/earthquake-hazards/crustal-deformation-monitoring) |
Creepmeter precision | Micron-precision measurements [[^]](https://cires1.colorado.edu/~bilham/creepmeter.file/creepmeters.htm) |
Creepmeter data frequency | Every 10 minutes [[^]](https://cires1.colorado.edu/~bilham/creepmeter.file/creepmeters.htm) |

**California's faults require real-time monitoring for seismic assessment**

California's faults require real-time monitoring for seismic assessment. Real-time data is crucial for assessing stress changes and crustal deformation on California's major fault systems, supporting seismic hazard assessment, earthquake early warning systems, and ongoing research into earthquake physics and crustal deformation [[^]](https://earthquake.usgs.gov/monitoring/deformation/data/)[[^]](https://earthquake.usgs.gov/monitoring/deformation/)[[^]](https://www.usgs.gov/programs/earthquake-hazards/crustal-deformation-monitoring). This comprehensive monitoring involves several types of instruments, including Global Positioning System (GPS) data, creepmeters, strainmeters, and tiltmeters.

GPS and creepmeters provide critical fault slip and deformation insights. Daily and near real-time GPS data are collected from extensive networks across the western U.S., including high-rate networks in the San Francisco Bay Area and Long Valley. This data provides critical insights into ground velocities, time series, and maps, allowing scientists to detect the relative motion between tectonic plates and understand fault slip [[^]](https://earthquake.usgs.gov/monitoring/deformation/)[[^]](https://www.usgs.gov/programs/earthquake-hazards/crustal-deformation-monitoring)[[^]](https://serc.carleton.edu/NAGTWorkshops/geodesy/activities/247762.html). Creepmeters are specifically designed to monitor "fault creep," which is the slow, continuous, and aseismic surface slip on certain faults. These instruments offer micron-precision measurements and are primarily located in areas such as the San Francisco Bay Area (Hayward, Calaveras, San Andreas faults) and near San Juan Bautista and Parkfield, with changes in creep rates indicating alterations in the shear strain applied to a fault [[^]](https://cires1.colorado.edu/~bilham/creepmeter.file/CaliforniaCreepmeterSRL.pdf)[[^]](https://cires1.colorado.edu/~bilham/creepmeter.file/creepmeters.htm)[[^]](https://earthquake.usgs.gov/monitoring/deformation/data/)[[^]](https://www.usgs.gov/publications/summary-creepmeter-data-1980-2020-measurements-spanning-hayward-calaveras-and-san)[[^]](https://pubs.geoscienceworld.org/ssa/srl/article-pdf/75/4/481/2757029/srl075004_0481.pdf).

Sensitive instruments like strainmeters and tiltmeters monitor subtle crustal changes. Highly sensitive strainmeters measure minute changes in crustal strain and are installed deep underground to minimize surface noise, providing continuous data on crustal deformation [[^]](https://earthquake.usgs.gov/monitoring/deformation/data/)[[^]](https://files.scec.org/s3fs-public/reports/2016/16073_report.pdf)[[^]](https://earthquake.usgs.gov/monitoring/deformation/data/instruments.php). These networks are strategically placed along active faults, including the San Andreas and Hayward faults, and in volcanically active regions like Long Valley, to monitor changes associated with fault slip, earthquakes, and volcanic activity [[^]](https://earthquake.usgs.gov/monitoring/deformation/data/instruments.php). Tiltmeters, often deployed alongside strainmeters and creepmeters, measure changes in the tilt of the ground, contributing to a comprehensive understanding of crustal deformation [[^]](https://earthquake.usgs.gov/monitoring/deformation/data/)[[^]](https://earthquake.usgs.gov/monitoring/deformation/data/instruments.php). Additionally, InSAR data aids in observing various deformation patterns, with its results validated by GPS monitoring data, while the USGS operates extensive seismic networks for rapid earthquake location and magnitude determination [[^]](https://earthquake.usgs.gov/learn/parkfield/seismic.php)[[^]](https://www.mdpi.com/2072-4292/15/1/143).

## What are the primary assumptions and limitations of the USGS's UCERF3 model when forecasting an M8.0+ event specifically before 2028?

Model forecasting M8.0+ events before 2028 | UCERF3 [[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture)[[^]](https://pubs.er.usgs.gov/publication/70147094)[[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-model)[[^]](https://pubs.usgs.gov/publication/ofr20131165) |
Alternative logic-tree branches for uncertainty | 1,440 [[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-model)[[^]](https://pubs.usgs.gov/publication/ofr20131165) |
Total forecast combinations | 5,760 [[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture)[[^]](https://pubs.er.usgs.gov/publication/70147094) |

**UCERF3 forecasts M8.0+ events using time-dependent elastic-rebound logic**

UCERF3 forecasts M8.0+ events using time-dependent elastic-rebound logic. This **model** applies elastic-rebound/renewal time-dependent logic to forecast M8.0+ seismic events specifically before 2028, incorporating magnitude-dependent aperiodicity and managing faults with unknown historic open intervals [[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture)[[^]](https://pubs.er.usgs.gov/publication/70147094)[[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-**model**)[[^]](https://pubs.usgs.gov/publication/ofr20131165). The framework accounts for epistemic uncertainty through a logic-tree set, which it represents by sampling 1,440 alternative logic-tree branches [[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture)[[^]](https://pubs.er.usgs.gov/publication/70147094)[[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-**model**)[[^]](https://pubs.usgs.gov/publication/ofr20131165). This process considers alternative deformation models, a new smoothed seismicity algorithm, different total rate values for M>=5 events, and various magnitude-scaling relationships as the most influential uncertainties affecting its forecasts [[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-**model**)[[^]](https://pubs.usgs.gov/publication/ofr20131165).

UCERF3 has significant limitations, including inability to **model** triggering processes. Key limitations of the UCERF3 framework include its inability to **model** earthquake-triggering processes or aftershocks [[^]](https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf)[[^]](https://www.usgs.gov/publications/a-spatiotemporal-clustering-**model**-third-uniform-california-earthquake-rupture-forecast). The **model** itself cautions that it serves as an approximation and that its sampled range of models is limited, for instance, being constrained to remain similar to UCERF2 [[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-**model**)[[^]](https://pubs.usgs.gov/publication/ofr20131165). Consequently, M8.0+ probabilities, particularly for the nearer future before 2028, inherit these structural constraints and are sensitive to the choices made within the **model** [[^]](https://www.usgs.gov/publications/uniform-california-earthquake-rupture-forecast-version-3-ucerf3-time-independent-**model**)[[^]](https://pubs.usgs.gov/publication/ofr20131165)[[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture). The predicted **probability** for a rare event like an M8.0+ can also shift substantially because UCERF3-TD employs renewal-**model** **probability** updates and logic-tree epistemic uncertainty, involving 5,760 forecast combinations depending on which branches dominate for the particular evaluation metric and region [[^]](https://www.usgs.gov/publications/long-term-time-dependent-probabilities-third-uniform-california-earthquake-rupture)[[^]](https://pubs.er.usgs.gov/publication/70147094).

## What Could Change the Odds

**Key takeaway.** The Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3) estimates California	s **probability** of an M8.0+ earthquake in the next 30 years at about **7.0%** (statewide), implying that the chance over only ~2.7 years (from 2026-05-06 to 2028-12-31) would be much smaller than **7%** and therefore the event is more likely than not to NOT occur before 2028-12-31 [[^]](https://www.conservation.ca.gov/cgs/Pages/Earthquakes/UCERF3.aspx).

**UCERF3 is the long-term forecast produced by USGS, California Geological Survey, Southern California Earthquake Center, and partners, and it specifically provides estimates for chances of large earthquakes over several decades [[^]](https://www.conservation.ca.gov/cgs/Pages/Earthquakes/UCERF3.aspx).** A Kalshi **market** exists for 	at least 8.0 magnitude earthquake in California	 with a deadline before Jan 1, 2027 (and other similar horizons exist), indicating that prediction-**market** participants are trying to quantify this low-frequency, high-impact tail risk [[^]](https://kalshi.com/markets/kxearthquakecalifornia/earthquake-in-california/kxearthquakecalifornia-27)[[^]](https://kalshi.com/markets/kxearthquakecalifornia/earthquake-in-california/kxearthquakecalifornia-28).

## Key Dates & Catalysts

- **Expiration:** January 07, 2029
- **Closes:** December 31, 2028

## Decision-Flipping Events

- The Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3) estimates California s **probability** of an M8.0+ earthquake in the next 30 years at about **7.0%** (statewide), implying that the chance over only ~2.7 years (from 2026-05-06 to 2028-12-31) would be much smaller than **7%** and therefore the event is more likely than not to NOT occur before 2028-12-31 [^] .
- UCERF3 is the long-term forecast produced by USGS, California Geological Survey, Southern California Earthquake Center, and partners, and it specifically provides estimates for chances of large earthquakes over several decades [^] .
- A Kalshi **market** exists for  at least 8.0 magnitude earthquake in California with a deadline before Jan 1, 2027 (and other similar horizons exist), indicating that prediction-**market** participants are trying to quantify this low-frequency, high-impact tail risk [^] [^] .

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## Historical Resolutions

No historical resolution data available for this series.

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