Final answer:
The bend in the Emperor-Hawaii seamount chain is caused by the Pacific 4. plate moving over a stationary hot spot, leading to volcanic activity and the creation of a chain of seamounts and islands with a directional change occurring roughly 43 million years ago.
Step-by-step explanation:
The bend in the Emperor-Hawaii seamount chain is primarily due to the movement of the Pacific 4. tectonic plate over a stationary mantle plume, also known as a hot spot. This hot spot is an area where heat from the Earth's interior rises to the surface, resulting in volcanic activity and the creation of volcanic islands such as the Hawaiian islands.
Over time, as the Pacific plate has moved, this activity has created a long chain of seamounts and islands that mark the plate's progression. The bend itself is attributed to a change in the direction of the Pacific plate's movement approximately 43 million years ago, which resulted in the change of direction of the seamount chain.