Final answer:
Surtsey is a volcanic island formed from 1963 to 1967 and is located in Iceland, part of the Vestmannaeyjar archipelago.
Step-by-step explanation:
The country where Surtsey was formed by volcanic activity from 1963 to 1967 is Iceland. Surtsey emerged as a new island off the coast of Iceland as a result of a volcanic eruption that began 130 meters below sea level.
This volcanic activity continued for several years, eventually creating the island which is now part of the Vestmannaeyjar archipelago, situated to the south of the main island of Iceland.