The Earth’s largest volcanic mountain range, extending from the oldest seamount, dated at 78 Ma ago, near Kamchatka to an active submarine volcano south-east of Hawaii. The chain is regarded as a plume trace (see mantle plume). It forms two distinct, gentle curves, with a kink dated at approximately 43 Ma ago and thought to be related to a change in the direction of movement of the Pacific Plate over a stationary hot spot.