Insights on the state of stress in the mantle beneath Pahala, Hawai‘i
Main Article Content
Abstract
Magma supply rates from the mantle to Hawaiian volcanoes serve as an important control on eruptive behavior at the surface. The Pa ̄hala Sill Complex, a collection of magma-bearing, seismogenic structures at 40 km depth beneath Hawai‘i, presents an opportunity to elucidate interactions between stress and magma transport processes in the mantle. We invert for full moment tensors of sill earthquakes and identify predominantly shear mechanisms with persistent tensile faulting components. Slip occurs in-plane with the sill structures. Pressure axes are radially oriented about a point near Mauna Loa, consistent with a stress field generated by a flexural load. Together, these observations suggest that magma flux through the sill structures generates seismicity by increasing pore pressure and promoting slip. Our results suggest that stress changes in mantle structures may enable fluctuations in magma supply rates to the surface over short timescales.
Downloads
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
Submission of an original manuscript to Volcanica will be taken to mean that it represents original work not previously published, and not being considered for publication elsewhere.
Accepted 2023-12-05
Published 2024-01-18