# Researchers in Switzerland and US model peak stress at Cajón Pass on San Andreas and San Jacinto faults

- Published: 2026-11-05 20:25 UTC
- Section: Planet › Earth sciences
- Tags: Cajón Pass, seismic gate, San Andreas Fault, San Jacinto Fault, tectonic stress simulation, three-dimensional model, Wrightwood earthquake 1812, southern California earthquake risk, Liliane Burkhard, megapascals
- URL: https://realtech.media/news/rt-ec07651c3ecdb6e8331fd59f_researchers_in_switzerland/

**A simulation of a thousand years of seismic history shows stress at Cajón Pass, where two faults meet, at its highest level in that period. The authors give no date for a quake.**

![Researchers in Switzerland and US model peak stress at Cajón Pass on San Andreas and San Jacinto faults](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/a1a2095e4710a1e5.avif)
*TV Azteca*

Researchers from institutions in Switzerland and the United States have identified what they call a "seismic gate" at Cajón Pass in southern California, where the San Andreas Fault and the San Jacinto Fault cross, according to TV Azteca. The team simulated a thousand years of seismic history and found that accumulated stress in the region reached its highest point in that period [1]. The study was led by Liliane Burkhard of the University of Bern together with specialists from the U.S. Geological Survey (USGS) and other institutions [1].

## Stress on two faults at once

The researchers used a three-dimensional model that tracked the behavior of the ground over time. According to the results, accumulated energy at Cajón Pass exceeded the maximum values of the past thousand years: 3.6 megapascals on the San Jacinto Fault and 2.8 megapascals on the San Andreas Fault [1]. The authors note that the concern is not only the magnitude of the stress but also that both faults reached their maximum levels at the same time [1].

Depending on the accumulated pressure, the pass can stop an earthquake on a single fault or let the rupture continue so that both faults break simultaneously [1]. A rupture of this kind occurred in the 1812 Wrightwood earthquake, which crossed the "gate" and fractured both systems together [1].

## Exposure and limits of the model

If such a scenario repeated, the shaking would cover a much larger area than a rupture on one structure [1]. Cajón Pass is a corridor for roads, railways and energy infrastructure leading to populated areas. A large event there would directly affect Los Angeles, San Bernardino, Riverside and the Coachella Valley, which have not recorded a large-scale earthquake since 1857 [1].

The authors state that the study does not set a date for a possible earthquake, since science cannot predict the exact moment of a quake [1]. The purpose of the physical models is to identify possible scenarios, in order to improve the preparedness of the population and the design of infrastructure [1].

## Sources

1. [TV Azteca](https://www.tvazteca.com/aztecanoticias/educacion/cientificos-de-suiza-y-eu-descubren-puerta-sismica-cerca-de-la-falla-de-san-andres-alertan-que-su-tension-es-la-mas-alta-en-mil-anos)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-ec07651c3ecdb6e8331fd59f_researchers_in_switzerland/