The novel MVP-LAI system and nighttime TEC perturbation amplifications
before earthquakes
Abstract
A novel system of Monitoring Vibrations and Perturbations in the
Lithosphere, Atmosphere, and Ionosphere (MVP-LAI) was established in
Leshan, Sichuan, China in 2021. The system comprises 14 distinct
instruments with 22 devices continuously monitoring changes in 14
geophysical parameters ranged between a few meter underground to
~350 km in altitude to examine and/or expose causal
mechanisms of the LAI couplings. Note that the ground-based GNSS
receivers of the system receive the electromagnetic signals from the
geostationary BeiDou satellites that retrieve the total electron content
over certain locations 24 × 7 without montage. Significant
amplifications of TEC perturbations appear during the night since
mid-May 2021. The M6.4 Yunnan and M7.4 Qinghai earthquakes occurred in
Mainland China on 21-22 May 2021. The amplifications are related with
the two earthquakes due to that the associated TEC perturbations reside
over the epicenters. The resident TEC perturbations and ground
vibrations close to the epicenters share a frequency of
~0.005 Hz, which can be attributed to the resonant
coupling between the lithosphere and ionosphere.