Final answer:
Japan did not form as a result of hotspot activity; it lies on a complex convergent plate boundary where multiple tectonic interactions, including earthquakes and volcanic eruptions, shape its geography.
Step-by-step explanation:
The question is asking which of the listed geographical features did not form as a result of a mantle plume or hotspot. The Hawaiian Islands and Kerguelen Plateau are known formations due to hotspot activity. The Ontong Java Plateau is also the result of a hotspot. On the other hand, Iceland is situated on the Mid-Atlantic Ridge where the North American and Eurasian plates are diverging, and hotspot activity contributes to its geothermal features.
However, the formation of Japan is associated with the complex interactions at a convergent plate boundary rather than a stationary hotspot. Earthquake activity, volcanic eruptions, and mountain building in Japan are a result of the subduction zones associated with the Pacific 'Ring of Fire', rather than a singular hotspot.