Thinning and Short-Term Prediction of Mw9.0+ Giant Earthquakes in Indonesia

Short-term prediction of giant earthquakes (Mw≥8.5) has long been a worldwide challenge in the field of Earth science. Traditional plate tectonic theory focuses on endogenous dynamics within the Earth's crust, making it difficult to explain the exact timing of giant earthquake triggering, the quantitative relationship with magnitude, and the correlation with the solar activity cycle. Based on the independently proposed "Atmospheric Spring Mechanism", this study systematically reveals that the 11-year solar sunspot cycle regulates the solar wind dynamic pressure, driving the vertical fluctuation of the global atmospheric boundary layer, forming a periodic physical process of "thickening for energy storage and thinning for pressure release". This process directly triggers giant thrust earthquakes in the circum-Pacific region through the migration of the center of gravity of surface pressure. Taking the Indonesia Sumatra-Sunda Strait-Andaman Sea region (the source area of the 2004 Mw9.1 giant earthquake, a key node of the circum-Pacific subduction zone and equatorial thermal coupling) as the core study area, we used 3-year pre-earthquake (May 2023 – May 2026) NOAA satellite planetary boundary layer height (PBLH) time series data, combined with tropical atmospheric density correction, 600–700 km upper atmospheric detection data, crustal seismic activity monitoring data, and low-altitude meteorological anomaly observations, to complete the time series analysis, quantitative calculation, and short-term risk assessment of the giant earthquake gestation process. The results show that the study area has fully experienced the entire "energy storage-pressure release" process of the atmospheric spring mechanism in the past 3 years before the earthquake. The period from May 2023 to November 2024 was the thickening and energy storage stage, during which the atmospheric boundary layer thickness increased continuously from the initial 945 m to a peak of 981 m, with a cumulative thickening of 36 m, meeting the giant earthquake energy storage threshold (≥33 m) set in this study. From December 2024 to May 2026, it entered the thinning and pressure release stage, during which the atmospheric boundary layer thickness decreased gradually from the peak to the current 949 m, with a cumulative thinning Δh≈32 m, which is very close to the giant earthquake triggering threshold of Δh≥33 m. Considering that the Indonesia region is located near the equator, where the atmospheric density is lower than the standard sea level average due to thermal uplift and centrifugal force effects, the tropical atmospheric density (ρ=1.165 kg/m³) was used for correction. The pressure release mass, pressure release energy, and theoretical magnitude were recalculated: the pressure release mass ΔM≈1.89×10¹⁶ kg (about 18.9 trillion tons), the pressure release energy E_release≈2.96×10¹⁸ J. Based on the globally recognized earthquake energy-magnitude conversion formula log₁₀E=1.5M+4.8 proposed by Kanamori (1977), the theoretical magnitude M_theory≈9.1 was inverted. Combined with the verification of multi-source abnormal signals: a lateral atmospheric evacuation phenomenon driven by strong pre-earthquake infrasound (0.1 Hz, above 100 Pa) from the crust appeared at 650 km altitude, with a pulsed sharp drop in atmospheric density; an abnormal low-pressure center and strong convergent wind field persisted in the low-altitude area, with a pressure drop rate significantly exceeding the normal seasonal background; dense shallow small earthquake swarms were active, with focal depths concentrated at 3–20 km, showing obvious fault pre-sliding characteristics. The above multi-source abnormal signals together form a complete short-term precursor chain of giant earthquakes, confirming that the study area has entered a short-term high-risk state of Mw9.0+ giant thrust earthquakes. This study for the first time combines the equatorial atmospheric amplification effect, infrasound-upper atmospheric evacuation mechanism with the atmospheric spring mechanism, establishing a complete quantitative physical chain of "solar activity-solar wind dynamic pressure-atmospheric boundary layer fluctuation-pressure release-crustal stress release-giant earthquake". It breaks through the limitations of traditional earthquake genesis theory, provides a verifiable, reproducible, and operable new paradigm for the short-term prediction of giant earthquakes, and has important theoretical innovation value and practical early warning significance.