Researchers used a novel finite-fault inversion method with seismometer data from around the world to investigate a deep intraslab earthquake that occurred on March 4, 2021, off the northeastern tip of New Zealand’s North Island. This imaging revealed complex rupture geometry that included shallow faulting with trench-perpendicular extension and unusual deep faulting with trench-parallel compression, possibly caused by seamount subduction and/or the transition between the Kermedec Trench and Hikurangi Margin, with different thicknesses of subducting oceanic crust.
