Question

which type of mass movement occur
a. earthflow
b. rockfall
c. slump
d. creep

Explanation:

To answer this, we analyze each mass movement type:

• Earthflow (A): Involves saturated soil/regolith flowing downslope, often in wet conditions.
• Rockfall (B): Rapid fall of rock fragments from a cliff/steep slope.
• Slump (C): Rotational movement of a mass along a curved surface (e.g., a slump block moving downslope).
• Creep (D): Extremely slow, imperceptible downslope movement of soil/regolith (e.g., tilted trees/fences), driven by gravity over long periods.

If the question implies a slow, gradual movement (common in contexts like long - term slope deformation), creep (D) is the most likely. However, since the original question’s full context (e.g., specific conditions like speed, material, slope type) is partially cut off, but based on typical definitions:

Answer:

D. creep