geophysics Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' so ...

and

seismology Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other ...

, the seismogenic layer covers the range of depths within the crust or lithosphere in which most

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s originate. The thickness is heavily dependent on location. For

oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic ...

, the seismogenic layer thickness can be 0-40 km, and for

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial'' be ...

, it ranges from 0-25 km. It is also important to note that at subduction zones, there is one seismogenic layer being pushed on top of another. This can result in extremely deep earthquakes up to 700 km in depth. The base of this layer represents the downwards change in deformation mechanism from elastic and frictional processes (associated with brittle faulting) to a generally

aseismic In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "after-slip" days to years after an earthquake. Notable examples of aseismic slip in ...

zone where ductile creep becomes the dominant process. The location of this change in deformation style is sometimes referred to as the brittle–ductile transition zone.

References

Structure of the Earth Seismology {{Seismology-stub