What does the bend in the Hawaiian Island Emperor seamount chain in the middle of the Pacific Plate suggest happened to the direction of Pacific plate movement about 50 million years ago?
The cause for this bend has been heavily debated for decades. One explanation is an abrupt change in the motion of the Pacific tectonic plate, the opposite model states southward drift of the mantle plume that has sourced the chain since its beginning 80 million years ago.
What caused the bend in the Hawaiian Emperor chain?
The Emperor and Hawaiian chains form an angle of about 120°. This bend was long attributed to a relatively sudden change of 60° in the direction of plate motion, but research conducted in 2003 suggests that it was the movement of the hotspot itself that caused the bend.
What caused the bend in the Hawaiian Island Emperor seamount chain and when did the bend form?
A crash caused the bend This northward migration continued from 80 to 50 million years, at which time the Emperor Chain was formed by the northern drift of the Pacific over the mantle plume.
What does the bend in the chain at 50 Ma indicate about the direction of the Pacific plate movement?
A sharp bend in the chain indicates that the motion of the Pacific Plate abruptly changed about 43 million years ago, as it took a more westerly turn from its earlier northerly direction.
What causes the Pacific plate to move?
The Pacific Plate is being moved north west due to sea floor spreading from the East Pacific Rise (divergent margin) in the Gulf of California. The North American Plate is being pushed west and north west due to sea floor spreading from the Mid Atlantic Ridge (divergent margin).
Why does the Pacific plate sink underneath the other plates?
Oceanic crust is denser than continental crust. At a subduction zone, the oceanic crust usually sinks into the mantle beneath lighter continental crust. (Sometimes, oceanic crust may grow so old and that dense that it collapses and spontaneously forms a subduction zone, scientists think.)