Seismic Strain Rate and Flexure at the Hawaiian Islands Constrain the Frictional Coefficient

Flexure occurs on intermediate geologic timescales (∼1 Myr) due to volcanic-island building at the Island of Hawaii, and deformational response lithosphere is simultaneously elastic, plastic, ductile. At shallow depths low temperatures, elastic deformation transitions frictional failure faults where stresses exceed a threshold value, this complex rheology controls rate manifested by earthquakes. In study, we estimate seismic strain based earthquakes recorded between 1960 2019 estimated with 10−18–10−15 s−1 in magnitude exhibits local minimum or neutral bending plane 15 km depth within lithosphere. comparison, flexure internal are modeled 3D viscoelastic loading models accommodated sliding limited coefficient (μf), larger low-temperature plasticity high-temperature creep. Observations best-reproduced μf = 0.3 ± 0.1 modified laboratory-derived plasticity. Results also suggest strong lateral variations strength beneath Hawaii. Our predict radial pattern compressive stress axes relative central Hawaii consistent observations earthquake pressure (P) axes. We demonstrate that dip angle axis essential discerning change curvature flexure, therefore has implications for constraining lithospheric strength.