Complex sentence: The tsunami which resulted from the Indian Ocean earthquake of 2004 inundated much of the area, partly damaging the lighthouse, which subsided 4.25 m. As a result of this subsidence, the coast retreated and the sea moved permanently inland.
Split into simpler sentences: The tsunami which resulted from the Indian Ocean earthquake of 2004 inundated much of the area. This partly damaged the lighthouse, which subsided 4.25 m. As a result of this subsidence, the coast retreated and the sea moved permanently inland.