Forearc

The region of a subduction zone between the ocean trench and volcanic arc. It can include an accretionary wedge, forearc basin, and forearc crust.

Subduction zone: A convergent plate boundary where one tectonic plate descends beneath another into the mantle. The forearc is one region within this broader plate-boundary system.
Megathrust earthquake: A large earthquake caused by sudden slip on the boundary between a subducting plate and an overriding plate. The forearc overlies much of the plate interface that can rupture in these earthquakes.
Nankai Trough: A subduction zone off southwest Japan where the Philippine Sea Plate descends beneath the Eurasian margin. Its forearc includes a well-studied accretionary wedge and sedimentary basins.
Seismogenic zone: The part of a fault system where frictional sliding can generate earthquakes. Its downdip and updip limits beneath forearcs remain central to earthquake-hazard estimates.
Oceanic trench: A long, narrow seafloor depression formed where one tectonic plate bends and descends beneath another. The trench marks the seaward edge of the forearc.
Slow slip event: A transient episode of fault slip that releases tectonic strain over days to months without strong shaking. Slow slip beneath some forearcs reveals how strain is released near the plate interface.
Cascadia subduction zone: A subduction zone off western North America where the Juan de Fuca Plate descends beneath the North American Plate. Its forearc records megathrust processes and includes the Coast Range and offshore basins.
Tsunami earthquake: An unusually slow, shallow earthquake that generates a tsunami larger than its seismic waves would suggest. Whether shallow forearc faults can rupture this way depends on their friction and structure.
Volcanic arc: A chain of volcanoes formed above a subducting plate, commonly on the overriding plate. The arc defines the landward limit of the forearc.
Subduction erosion: The removal of material from the base or front of an overriding plate by a subducting plate. It can thin or remove forearc crust, unlike accretion that builds an outer wedge.

Linked from 8 pages