Direct estimation of earthquake source properties from a single CCTV camera.

Area of Science:

• * Seismology
• * Earthquake rupture dynamics

Background:

• * Understanding coseismic rupture processes is crucial for seismic hazard assessment.
• * Direct measurements of slip-rate functions during large earthquakes are rare.

Purpose of the Study:

• * To directly measure the slip-rate function of a natural coseismic rupture.
• * To characterize the mechanical properties of seismic rupture using elastodynamic models.

Main Methods:

• * Analysis of high-resolution video footage from a CCTV camera near the surface rupture.
• * Direct image analysis to quantify slip over time and deduce slip rate.
• * Application of slip-pulse elastodynamic rupture models.

Main Results:

• * Measured a local slip duration of 1.4 seconds for the 2025 Mandalay earthquake.
• * Determined a cumulative slip of approximately 3 meters.
• * Observed peak surface slip velocities reaching ~3.5 meters per second.
• * Demonstrated the pulse-like nature of the seismic rupture at the recording site.

Conclusions:

• * The study provides the first direct measurement of a slip-rate function from a natural earthquake rupture.
• * Findings confirm the pulse-like characteristics of seismic rupture propagation.
• * Elastodynamic modeling allowed for the determination of complete mechanical properties of the slip pulse.