EGU22-5668, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Quantifying the contributions of Pacific Plate motion change and hotspot drift to the formation of Hawaiian-Emperor Bend

Jiashun Hu1, Michael Gurnis2, Johann Rudi3, Georg Stadler4, Dietmart Müller5, and Jie Zhang1
Jiashun Hu et al.
  • 1Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen 518055, China (
  • 2Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
  • 3Mathematics and Computer Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
  • 4Courant Institute of Mathematical Sciences, New York University, NY 10012, USA
  • 5School of Geosciences, The University of Sydney, Sydney NSW 2000, Australia

The Hawaiian-Emperor Seamount Chain changed its strike by 60° around 47 Ma, causing the Hawaiian-Emperor Bend (HEB). Both a change in Pacific Plate motion and a change in plume dynamics have been proposed to account for the HEB, but vigorous debates remain on their relative contribution. In order to have a better understanding, we build high–resolution global mantle convection models and test alternative plate reconstructions of North Pacific to quantify the contribution of each mechanism. For the contribution of Pacific Plate motion change, we find that Izanagi Plate subduction, followed by demise of the Izanagi–Pacific ridge and Izu–Bonin–Mariana subduction initiation alone, is incapable of causing a sudden change in plate motion, challenging the conventional hypothesis on the mechanisms of Pacific Plate motion change. Instead, with the alternative intra-oceanic subduction model, the Paleocene slab pull from Kronotsky subduction in North Pacific exerts a northward pull on the Pacific Plate, with its demise causing a sudden 30-35° change in plate motion. We further quantify the Hawaiian Hotspot drift using global mantle convection models with both the traditional and the alternative plate reconstructions. We find both models yield a fast southward drifting Hawaiian plume due to the push of slabs on the edge of the Pacific LLSVP. In the end, we discuss the combinational effects of Pacific Plate motion change and Hawaiian hotspot drift on the formation of HEB under different scenarios to gain insights on the possible history of North Pacific since the Late Cretaceous.

How to cite: Hu, J., Gurnis, M., Rudi, J., Stadler, G., Müller, D., and Zhang, J.: Quantifying the contributions of Pacific Plate motion change and hotspot drift to the formation of Hawaiian-Emperor Bend, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5668,, 2022.