![sumatra java slab xsection sumatra java slab xsection](https://pic.stonecontact.com/picture201511/20174/139567/java-slate-p539122-4b.jpg)
The inset box shows the area represented in Figures 4 and S6. The west and south edges of our regional model are shown and correspond to the limits of the layers in Figure 3. ETOPO5 bathymetry, tectonic boundaries, and convergence vectors are also shown. Volcanoes are shown as magenta triangles (Toba Caldera is blue). Also shown are the Harvard Centroid Moment Tensor solutions, epicenters, rupture areas of the 20 megathrust earthquakes and the locations of the Investigator Fracture Zone (IFZ) and Wharton Fossil Ridge (WFR). Map of the Burma, Andaman, and Sumatra subduction zones showing the positions of the cross-sections in Figure 2. Finally, we show that, in the lower mantle, the ancient Neo-Tethys slab is a distinct and prominent feature. In addition, we present evidence for a significant tear in the upper mantle slab below Burma. We interpret folding of the subducting slab beneath northern Sumatra and speculate on its relation to shallow structure and seismogenesis.
![sumatra java slab xsection sumatra java slab xsection](https://api.time.com/wp-content/uploads/2015/02/lcg0891.jpg)
In our new model, the fast subducting slab is well imaged in the upper mantle throughout the region, with significant variations in dip along strike. 1 This increase in data allows us to use smaller model cell sizes and results in significant improvements in slab amplitude recovery. We focus on the Burma (Myanmar), Andaman, and Sumatra subduction zones ( Figure 1), where new data provided by the 2004–2005 megathrust sequences ( Figure S1) provide a substantial increase in ray coverage ( Figure S2). In this study, we perform a tomographic inversion of teleseismic data using a nested regional-global approach in order to determine the P-wave velocity structure of the Indonesia region. Consequently, there is great interest in characterizing the nature of the incoming and downgoing plate in order to determine how the plate geometry may be affecting subduction and seismogenesis. M w 8.7 megathrust earthquakes ( Figure 1). It is also the boundary between the rupture areas of the 2004 M w 9. This area also hosts subduction of the Investigator Fracture Zone (IFZ) and the Wharton Fossil Ridge (WFR), and is the locus of the southeast termination point of the diffuse deformational boundary between the Indian and Australian plates. The boundary between the Andaman and Sunda subduction zones is marked by a distinct bend in the trench offshore northern Sumatra.