Plain Language Summary
Earthquake is produced by sudden shear dislocation across the fault. The
geometric complexity of fault structure, such as bend, step-over,
branching and bifurcation, play important roles in determining the final
rupture dimension (hence the magnitude) of the earthquake, as they can
easily produce stress heterogeneity on the faults. Although geological
and recent space geodetic observations have well-recorded the fault
geometry complexity, detailed spatial and temporal evolution of rupture
through such fault segments, especially fault bifurcations, are rarely
well-imaged. In this study, we integrate broadband seismic waveform and
geodetic observations for the 2021 Mw7.4 Maduo earthquake in China, and
process and model them with a set of tools, to produce a high resolution
rupture model for the earthquake. The preferred model reveals a near
constant rupture speed of 2.5 km/s throughout the entire rupture, and
resolves the detailed rupture process through the bifurcated fault
segments at its eastern terminal, where the termination of the rupture
on the southern branch stopped the rupture on the northern branch.