Episodic back-arc spreading centre jumps controlled by transform fault to overriding plate strength ratio

Schliffke, Nicholas; van Hunen, Jeroen; Allen, Mark B.; Magni, Valentina; Gueydan, Frédéric

Abstract

Spreading centre jumps are a common feature of oceanic back-arc basins. Jumps are conventionally suggested to be triggered by plate velocity changes, pre-existing weaknesses, or punctuated events such as the opening of slab windows. Here, we present 3D numerical models of back-arc spreading centre jumps evolving naturally in a homogeneous subduction system surrounded by continents without a trigger event. Spreading centres jump towards their subduction zone if the distance from trench to spreading centre becomes too long. In particular, jumps to a new spreading centre occur when the resistance on the boundary transform faults enabling relative motion of back-arc and neighbouring plates is larger than the resistance to break the overriding plate closer to trench. Time and distance of spreading centres jumps are, thus, controlled by the ratio between the transform fault and overriding plate strengths. Despite being less complex than natural systems, our models explain why narrow subducting plates (e.g. Calabrian slab), have more frequent and closely-spaced spreading jumps than wider subduction zones (e.g. Scotia). It also explains why wide back-arc basins undergo no spreading centre jumps in their life cycle.

Citation

Schliffke, N., van Hunen, J., Allen, M. B., Magni, V., & Gueydan, F. (2022). Episodic back-arc spreading centre jumps controlled by transform fault to overriding plate strength ratio. Nature Communications, 13(1), Article 582. https://doi.org/10.1038/s41467-022-28228-5

• Journal Article Type: Article
• Acceptance Date: Dec 10, 2022
• Online Publication Date: Jan 31, 2022
• Publication Date: 2022
• Deposit Date: Feb 3, 2022
• Publicly Available Date: May 19, 2022
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Article Number: 582
• DOI: https://doi.org/10.1038/s41467-022-28228-5
• Public URL: https://durham-repository.worktribe.com/output/1215075