The given beach-ball figure denotes the focal mechanism corresponding to which one of the following faults?
\includegraphics[width=0.5\linewidth]{16.png}
Show Hint
- oblique slip normal
- thrust
- strike-slip
- normal
The Correct Option is C
Solution and Explanation
A beach-ball diagram represents the fault-plane solution of an earthquake using seismic wave first-motion patterns. The shaded quadrants indicate compression, while the unshaded quadrants represent dilation. Step 2: Identifying the pattern.
The given beach-ball diagram shows alternating quadrants shaded and unshaded in a cross-like symmetry. This pattern is characteristic of strike-slip faulting, where the motion is dominantly horizontal. Step 3: Eliminating incorrect options.
- Oblique slip normal: Involves both dip-slip and strike-slip; its focal mechanism would not show perfect quadrant symmetry.
- Thrust: Produces two opposite shaded quadrants on top and bottom, unlike the given pattern.
- Normal: Produces two opposite shaded quadrants on left and right, also not matching the figure.
Thus, the alternating quadrant pattern uniquely corresponds to a strike-slip fault. \[ \boxed{\text{Hence, the focal mechanism corresponds to a strike-slip fault.}} \]
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