Why are the Hawaiian volcanoes in the middle of the Pacific Ocean?
We have learned in class that volcanoes occur at plate boundaries, particularly at divergent and convergent types. However, if we look at the Hawaiian volcanic island chain, we see that it is not located at the edge of a plate. Figure 1. This map shows the north-central part of the Pacific Ocean sea floor. The boundaries of the Pacific plate are near the edges of the Pacific Ocean. The volcanically active Hawaiian islands, however, are located in the middle of the Pacific plate. They are part of a long chain of seamounts that extends westward and northward to the Aleutian trench. The seamounts of the Hawaiian Ridge and Emperor Seamount Chain are volcanoes that are no longer active and that have sunk below sea level. The dates on Figure 1 (<1 my to 70 my) are the ages of the volcanoes; they indicate when lava extruded from the sea floor to form the labeled island or seamount (my = million of years). Figure 2. This diagram explains the progression of ages observed in the Hawaiian / Emper
