Mariana Trough

The Mariana Trough is an active back-arc basin in the western Pacific Ocean (Stern, Fouch & Klemperer 2003).

The Mariana Trough stretches 1300 km from north to south, about the distance from Los Angeles CA to Portland OR, Tokyo, Japan to Seoul, Korea, or London, England to Rome, Italy.

The deepest part of the Central Graben is also unique among active back-arc basins in exposing mantle peridotites along the extension axis (Stern et al. 1996).

Extension north of the Central Graben occurs by combined tectonic and magmatic processes that are distinct from seafloor spreading, in a region known as the Volcano-Tectonic Zone (VTZ; Martinez et al.).

The northern VTZ is dominated by point-source volcanism, with edifices spaced 50–60 km apart alternating with rift basins.

The Mariana Trough
lies in the southern part of the IBM arc system in the Western Pacific. Guam and The Northern Mariana Islands mark its eastern limit.
Bathymetry of the Mariana Trough and surroundings. The figure was generated by Dr. F. Martinez University of Hawaii using open source software GMT version 4.14 [1] and data bases (Smith and Sandwell and Smith global measured and predicted bathymetry file topo_9.1.img, [2] )