Moment Tensors of Ring‐Faulting at Active Volcanoes: Insights Into Vertical‐CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands

A new method to estimate ring-fault parameters from vertical-CLVD earthquakes has been developed, offering insights into the kinematics and structures below active volcanoes. The study demonstrates that long-period seismic waves can resolve two key moment tensor components—vertical-CLVD and vertical strike-slip—while a third component (vertical dip-slip) remains indeterminate due to shallow source depth. Applied to earthquakes during the 2005 and 2018 volcanic activities at Sierra Negra caldera, Galápagos Islands, this approach validated ring-fault geometry consistent with geodetic studies and revealed significant differences in slip direction and location between two events. This breakthrough enables global examination of ring-fault systems, enhancing understanding of volcanic processes.

Sandanbata, O., Kanamori, H., Rivera, L., Zhan, Z., Watada, S., & Satake, K. (2021). Moment Tensors of Ring‐Faulting at Active Volcanoes: Insights Into Vertical‐CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands. Journal of Geophysical Research: Solid Earth, 126(6). Portico. https://doi.org/10.1029/2021jb021693