Determination of Radiated Energy and Energy-Moment Ratio for the 2025 Tibet Dingri 6.8 Magnitude Earthquake

Seismic radiation energy is a quantitative characteristic of the seismic source that not only depends on the initial and final stresses but also on the rupture history, reflecting the dynamic characteristics of the source. The energy-to-moment ratio is the seismic wave energy radiated per unit seismic moment, and it represents the balance between stress drop, rupture velocity, and variations in shear wave velocity. Earthquakes with a high energy-to-moment ratio release strain energy more rapidly. Accurately and quickly determining seismic radiation energy and the energy-to-moment ratio plays an important role in seismic hazard assessment, quantitative earthquake research, and engineering seismology. In this study, we used waveform data from the global seismic network to measure the dynamic source parameters, including the radiation energy, energy-to-moment ratio, duration parameter, and apparent stress of the earthquake that occurred on January 7, 2025, in Dingri, Tibet. Static source parameters, such as seismic moment and moment magnitude, were also determined. The main results are as follows: (1)The radiation energy of this earthquake is 9.73×10¹⁴J, corresponding to an energy magnitude M_e of 7.1, with a rupture duration of 24 seconds. (2)The source mechanism of this earthquake is normal faulting, with a seismic moment of 4.98×10¹⁹N·m, corresponding to a moment magnitude M_W of 7.1. The fault plane parameters are as follows: Plane I: 191°/32°/-67°, Plane II: 344°/60°/-104°, and the depth of the centroid is 12.3 km. (3)The energy-to-moment ratio of this earthquake is 1.95×10⁻⁵, the duration parameter is -4.71, and the apparent stress is 0.59 MPa. The energy-to-moment ratio is higher than the average level for normal-fault earthquakes in mainland China. In conclusion, this earthquake is a normal-fault earthquake with a relatively high energy release efficiency, indicating a significant potential for damage to local buildings and infrastructure. The earthquake caused severe damage to ground structures and significant casualties in the near field.