A two-way interaction between the Hainan plume and the Manila subduction zone

• Published in: Geophysical research letters Vol. 42; no. 14; pp. 5796 - 5802
• Main Authors: Mériaux, Catherine A., Duarte, João C., Schellart, Wouter P., Mériaux, Anne-Sophie
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 28-07-2015; John Wiley & Sons, Inc
• Subjects: analogue modeling; Buoyancy; Buoyancy flux; Camber; Conduits; Earth mantle; Flux; Geophysics; Laboratory models; Mantle; Mantle plumes; Plate tectonics; Plumes; Ratios; Return flow; Scale models; Seismology; Slabs; Subduction; Subduction (geology); Subduction zones; Three dimensional models; Tilt; Upper mantle; China, People's Rep., Hainan
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2015GL064313

The interaction between mantle plumes and subducting slabs is well accepted, but the influence of slabs on plumes has more often been portrayed than the reverse. Here we present three‐dimensional upper mantle laboratory models in which a compositional plume rises underneath a subducting plate. Slab/plume buoyancy flux ratios ranged between 7 and 18. The models exhibit a two‐way interaction. While the plume conduit increasingly tilts away from the trench as a result of slab rollback‐induced toroidal mantle flow, the slab subduction rate decreases as a function of the amount of plume buoyancy opposing that of the slab, which gets subducted beneath the slab. We propose that our models apply to the Hainan/Manila system and explain the recently imaged tilt of the Hainan plume by the Manila slab‐induced mantle return flow. The Hainan plume could lessen the Manila subduction rate from 8 Ma into the future.
Key Points
Subducting slabs can influence plumes and vice versa
Tilt of the Hainan plume is caused by the Manila slab rollback‐induced flow
The Manila subduction rate is to decrease due to the Hainan plume