In geology, a backstop is the region of forearcs that has much higher shear strength and yield strength than other overriding material closer to the oceanic trench.[1][2] The area between the backstop and the trench deforms more than the area from the backstop away from the trench, resulting in different degrees of accumulated deformation.[2] In other words, it can be said that the backstop is relatively resistant to deviatoric stresses induced by subduction.[2]