seismogenic layer

In geophysics and seismology, the seismogenic layer or seismogenic zone covers the range of depths within the crust or lithosphere in which most earthquakes originate.{{cite book |url = https://books.google.com/books?id=JL1VM5wMbrQC |title = The Mechanics of Earthquakes and Faulting |last = Scholz |first = Christopher |publisher = Cambridge University Press |year = 2002 |isbn = 9780521655408|page = 152 |access-date = June 12, 2012}} The thickness is heavily dependent on location. For oceanic crust, the seismogenic layer thickness can be {{convert|0|to|40|km|mi}}, and for continental crust, it ranges from {{convert|0|to|25|km|mi}}.{{Cite journal|last=Watts|first=A.B.|last2=Burov|first2=E.B.|date=August 2003|title=Lithospheric strength and its relationship to the elastic and seismogenic layer thickness|journal=Earth and Planetary Science Letters|volume=213|issue=1–2|pages=113–131|bibcode=2003E&PSL.213..113W|doi=10.1016/S0012-821X(03)00289-9}} 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 {{convert|700|km|mi}} in depth.{{Cite web|url=https://www.usgs.gov/faqs/what-depth-do-earthquakes-occur-what-significance-depth?qt-news_science_products=0#qt-news_science_products|title=At what depth do earthquakes occur? What is the significance of the depth?|last=Hayes|first=Gavin|last2=Crone|first2=Tony|publisher=United States Geological Survey}} 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 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.

{{Cite journal

| last1 = Cole | first1 = J.

| last2 = Hacker | first2 = B.

| last3 = Ratschbacher | first3 = L.

| last4 = Dolan | first4 = J.

| last5 = Seward | first5 = G.

| last6 = Frost | first6 = E.

| last7 = Frank | first7 = W.

| doi = 10.1029/2007JB004975

| title = Localized ductile shear below the seismogenic zone: Structural analysis of an exhumed strike-slip fault, Austrian Alps

| journal = Journal of Geophysical Research

| volume = 112 | issue = B12

| pages = B12304

| year = 2007

| bibcode = 2007JGRB..11212304C| url = http://www.geol.ucsb.edu/faculty/hacker/viz/Cole07_brittle_ductile_strike_slip.pdf |doi-access=free

}}