The Hawaiian–Emperor seamount chain is divided, as the name indicates, into the Hawaiian and Emperor seamount chains. The Emperor part did form in a different way than the Hawaiian part:
‘…it has been discovered that Empereror volcanism migrated south by at least 800km and possibly by as much as 2000km, across a slow-moving or even stationary Pacific plate during formation of the chain.’ ((Foulger (2010) https://www.wiley.com/en-ie/Plates+vs+Plumes:+A+Geological+Controversy-p-9781405161480)
Therefore, the picture of formation + drift processes looks like this:
This can be compared to the convection rolls system shown below:
It is quite obvious what has happened according to the Convection Rolls Model. The whole central line of the Pacific started to divide the plate, in the same way as the central ridge of the Atlantic Ocean. Before the division was complete, though, the Pacific Plate started drifting westwards, leaving only the hub of Hawaii active.
Further information: https://en.wikipedia.org/wiki/Hawaiian%E2%80%93Emperor_seamount_chain