Rocks.<br>A bunch of waves went over the cliffs. The weathering started to take a toll. Some rocks began to fall. They made a splash in the waves. The rocks fell to the bottom of the ocean.
The rocks hit the seabed after the avalanche.
The rocks fell off the cliffs (an avalanche) and to the bottom of the ocean, landing on the seabed. I believe using words not in the original tricked the system.
( z1 hit :ARG1 ( z2 seabed ) :ARG2 ( z3 rock ) :time ( z4 after :op ( z5 avalanche ) ) )