Density Structure of the Papua New Guinea-Solomon Arc Subduction System

The Papua New Guinea-Solomon (PN-SL) arc is one of the regions with active crustal motions and strong geological actions. Thus, its complex subduction system makes it an ideal laboratory for studying the initiation mechanism of plate subduction. However, the PN-SL subduction system has not yet been sufficiently studied, and its density structure has yet to be revealed. In this paper, we used the free-air gravity data, Parker-Oldenburg density surface inversion method, and the genetic algorithm density inversion method to obtain the density structure of an approximately 1000-km-long northwest-southeast line crossing the PN-SL subduction system under the constraints of the CRUST1.0 global crustal model, onshore seismic data, and the LLNL-G3Dv3 global P-wave velocity model. The density structure shows that density differences between the plates on the two sides of the trench could play a significant role in plate subduction.

Automated summary

The Papua New Guinea-Solomon (PN-SL) arc is a region with active crustal motions and strong geological actions. In this study, researchers used gravity data and density inversion methods to reveal the density structure of the PN-SL subduction system. The results show that density differences between the plates on the two sides of the trench play a significant role in plate subduction. However, further research is still needed for this subduction system.