Ionospheric TEC anomalies precede large earthquakes by up to two months

A team of researchers reports that the total electron content of the ionosphere rises measurably in the weeks before the largest earthquakes, and that the timing of these events shows statistical patterns the authors link to a speculative dark matter scenario. The study, published in Discover Space, analyzed global ionospheric maps and earthquake catalogs spanning nearly two decades, and its authors argue that the same GPS infrastructure used to monitor the upper atmosphere could eventually serve as a real-time warning system for catastrophic seismic events.

The researchers, led by Konstantin Zioutas of the University of Patras with collaborators across Europe, Turkey, and the United States, focused on earthquakes of magnitude 8 and above. Using daily averaged total electron content, or TEC, measurements from the Center for Orbit Determination in Europe covering 1 January 1995 to 30 December 2012, they aligned the ionospheric record with the dates of the twenty largest earthquakes in that window. The technique they employed, superposed epoch analysis, stacks multiple time series around a common reference point so that incoherent daily fluctuations cancel out while signals tied consistently to the reference events survive.

What emerged was a slow increase in global ionospheric electron content beginning roughly 45 days before the large earthquakes. The twenty-event stack, which included four events whose analysis windows overlapped, yielded a statistical significance of 3.7 sigma when the peak was compared against a quiet baseline drawn from periods 60 to 90 days before and after each event. Restricting the analysis to the sixteen non-overlapping events produced similar long-term behavior, suggesting the result was not an artifact of a few unusually close pairs of earthquakes.

The signal grew stronger when the team narrowed the sample to the five largest events, all of magnitude 8.6 or greater. For this subset, the TEC rise appeared approximately 1.5 months before the earthquakes, and the cumulative anomaly reached a significance of 7.1 sigma relative to the same background interval. The authors emphasize that this scaling of significance with earthquake magnitude is central to their interpretation: if the ionospheric rise were merely a byproduct of solar storms or geomagnetic activity, its strength should not depend on how much energy the crust releases.

To test that point directly, the researchers examined more than 2,800 earthquakes sorted into six magnitude classes from magnitude 6.0 to magnitude 8.5 and above. The significance of the TEC anomaly climbed with magnitude, reaching 2.19 sigma for events between magnitude 8.0 and 8.4 and 7.1 sigma for the most catastrophic class, while smaller events below magnitude 7.5 generally stayed within the 1.96-sigma threshold that marks the 95 percent confidence level. One apparent exception, a 2.07-sigma value in the magnitude 6.2 bin, the authors attribute to the sheer size of that sample, 1,953 events, which minimizes the background variance and can elevate otherwise modest signals.

The team also attempted a conventional Monte Carlo validation, replacing the real earthquake dates with 1,000 sets of random dates. That approach proved unreliable, they report, because random selections frequently captured periods of high solar flare activity or geomagnetic storms, which can raise global TEC by an order of magnitude and mask any seismic-related signal. The 11-year solar cycle biases the shuffled baselines so heavily, the authors argue, that simple date shuffling is an inefficient tool for characterizing the coupling between the lithosphere and the ionosphere in raw data.

Beyond the ionospheric record, the study identified two further statistical patterns in earthquake occurrence itself. Projecting more than 15,000 earthquakes with magnitudes above 5.2, recorded between 2001 and 2015, onto the heliocentric longitude of Venus, the team found a pronounced excess of events near a longitude of about 260 degrees, with a significance of 4.4 sigma. When the dataset was split into two independent halves, the excess persisted in the same longitude range at roughly 4 sigma in each period, which the authors take as evidence that the clustering is not driven by a small subset of events. They also report that the pattern survives when days with more than ten earthquakes are excluded, addressing the moderate overdispersion they observed relative to a Poisson distribution of daily event counts.

A Lomb-Scargle periodogram analysis of the same filtered catalog produced a dominant peak at 27.32 days, matching the Moon’s sidereal period, the time the Moon takes to return to the same position relative to the distant stars. The familiar 29.53-day synodic period, which governs lunar phases and the tidal stresses most often invoked in seismology, was absent. The sidereal peak exceeded the local spectral background by 7.4 sigma. The authors argue that this combination, a strong sidereal signal with no synodic counterpart, is difficult to reconcile with tidal forcing, and they further contend that a solar space-weather driver would produce a broadened peak given the Sun’s differential rotation between roughly 25 and 32 days, rather than the sharp 0.05-day-wide feature they observe.

The mechanism the authors propose to explain these patterns is speculative. They invoke axion quark nuggets, a dark matter candidate described as strongly interacting composite objects that would deposit energy along trajectories through the Earth and atmosphere. Under this scenario, gravitational focusing by solar system bodies could amplify the flux of such streams by several orders of magnitude during planetary alignments, with atmospheric energy deposition driving the TEC rise and acoustic overpressure in the crust, estimated between 0.03 and 0.3 pascals, acting as a small trigger in regions already near critical tectonic stress. The authors stress that the energy released in an earthquake remains governed by long-term geological stress accumulation, with any dark-sector influence serving only as an initiator. They also note that the observed precursors do not depend on this specific model and could be compatible with other dark sector constituents.

The practical claim advanced in the paper is that continuous global GPS monitoring, combined with archival earthquake records, could support simulations estimating the likely timing and approximate epicentral region of a future large earthquake in real time, with lead times of roughly 1.5 to 2 months for the largest events. The authors contrast their global approach with regional case studies, including investigations of the magnitude 5.7 Ain Temouchent and magnitude 6.4 Al Hoceima earthquakes in North Africa, which reported precursor lead times of a few days to roughly two weeks, a difference they attribute to magnitude-dependent preparation zones and to the greater sensitivity of local networks to late-stage processes near the epicenter. Whether the reported ionospheric and planetary correlations will withstand independent scrutiny, and whether they translate into reliable forecasts, remains to be demonstrated by future validation on out-of-sample data.

Subject of Research: Month-scale ionospheric total electron content anomalies preceding large earthquakes and their proposed dark matter interpretation

Article Title: Evidence for a month-scale ionospheric precursor to large earthquakes as an outcome of dark matter research

Article References: Zioutas, K., Akman, E., Argiriou, A., Cantatore, G., Cetin, S. A., Guo, J., Karuza, M., Kryemadhi, A., Lazanu, I., Maroudas, M., Ozbozduman, K., Parvu, M., & Semertzidis, Y. (2026). Evidence for a month-scale ionospheric precursor to large earthquakes as an outcome of dark matter research. Discover Space, 130(1), Article 13. https://doi.org/10.1007/s11038-026-09593-3

Image Credits: AI Generated

DOI: 10.1007/s11038-026-09593-3

Keywords: earthquakes, ionosphere, total electron content, GPS, dark matter, axion quark nuggets, seismic forecasting, superposed epoch analysis, planetary alignment, lunar sidereal period, solar cycle, TEC anomalies