Imaging the 2016 Mw 7.8 Kaikoura, New Zealand, earthquake with teleseismic P waves: A cascading rupture across multiple faults

Abstract The 13 November 2016 Mw 7.8 Kaikoura, New Zealand, earthquake was investigated using teleseismic P waves. Backprojection of high‐frequency P waves from two regional arrays shows unilateral rupture of at least two southwest‐northeast striking faults with an average rupture speed of 1.4–1.6 km/s and total duration of ~100 s. Guided by these backprojection results, 33 globally distributed low‐frequency P waves were inverted for a finite fault model (FFM) of slip. The FFM showed evidence of several subevents; however, it lacked significant moment release near the epicenter, where a large burst of high‐frequency energy was observed. A local strong‐motion network recorded strong shaking near the epicenter; hence, for this earthquake the distribution of backprojection energy is superior to the FFM as a guide of strong shaking. For future large earthquakes that occur in regions without strong‐motion networks, initial shaking estimates could benefit from backprojection constraints.