noun
earthquake fault
A fracture in the Earth's crust along which displacement has occurred during an earthquake. Used in geology and seismology.
この地域には活発な地震断層がいくつか存在する。
Several active earthquake faults exist in this region.
地震断層の調査は防災にとって重要だ。
Investigation of earthquake faults is important for disaster prevention.
活断層 specifically refers to an active fault with potential for future earthquakes, while 地震断層 is a broader term for any fault associated with an earthquake.
Compound of 地震 (earthquake) and 断層 (fault). The term is a direct combination of its components, with no irregular historical derivation.