WadatiBenioffzóna

The WadatiBenioff zone, often referred to as a Benioff zone or WadatiBenioff area, is a feature of plate tectonics. It describes a tilted plane in the Earth's mantle where shallow earthquakes occur at the surface, and then the earthquakes get progressively deeper as they move away from the trench. This zone is associated with convergent plate boundaries, specifically where oceanic crust is subducting beneath another plate, which can be either continental or oceanic.

The phenomenon was independently proposed by Kiyoo Wadati and Hugo Benioff in the 1930s and 1940s. They observed that earthquake hypocenters, the points within the Earth where an earthquake originates, were not randomly distributed but rather occurred in a planar zone dipping beneath the overriding plate. This observation provided crucial evidence for the theory of plate tectonics and the process of subduction.

The WadatiBenioff zone extends from the surface at a deep oceanic trench down into the mantle. The angle of dip varies but is typically around 45 to 60 degrees. As the subducting oceanic plate sinks, it cools and dehydrates, leading to a series of earthquakes. The composition and temperature of the subducting slab influence the types of seismic activity observed. Deeper earthquakes within the WadatiBenioff zone are often associated with increased pressure and temperature, and can sometimes be larger in magnitude. Understanding the characteristics of WadatiBenioff zones is vital for seismologists in assessing seismic hazard in subduction zone regions.