Why does the study of volcanoes around the ring of fire start in alaska?

The volcanoes are studied around ring of fire because 70% of volcanoes in US are found in that region.

Explanation:

The cause of "ring of fire" is the subduction of tectonic plates in northern portion.  

Ring of fire is areas in Pacific Ocean where the volcanic eruption and earthquake frequently occur. The volcanic eruption and earthquake occur mainly due to the plate movements.

The plate that carry ocean is denser than that of continental plates and the collision of such plate creates earthquake and volcanic eruption.

The investiture controversy began as a power struggle between pope gregory vii (1072–85) and henry iv, holy roman emperor (1056–1106).[2] a brief but significant struggle over investiture also occurred between henry i of england and pope paschal ii in the years 1103 to 1107, and the issue played a minor role in the struggles between church and state in france, as well.by undercutting the imperial power established by the salian emperors, the controversy led to nearly 50 years of civil war in germany, and the triumph of the great dukes and abbots. imperial power was finally re-established under the hohenstaufen dynasty. historian norman cantor: