Below the surface, then, a fault can be bounded on all sides by a continuous tip line that connects at both ends with the surface trace of the fault. A blind thrust, however, does not break the surface anywhere and thus is completely surrounded by a termination line that either a tip line or a branch line (see below). Later, possibly long after active faulting ceases, the tip line at the top of the fault surface may be eroded away to create a trace of the fault on the Earth's surface.