Final answer:
Plate tectonics is the theory that was controversial and began to be accepted in the 1960s after the Alaskan megaquake.
Step-by-step explanation:
The theory that was controversial when it began to be accepted in the 1960s after the Alaskan megaquake raised interest and awareness in geosciences is plate tectonics. Plate tectonics is the scientific theory that describes the movement and interactions of Earth's lithospheric plates. It explains the formation of fault lines, earthquakes, and the movement of the magnetic poles of the Earth.
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