The southern portion of the ring of fire is complex due to the presence of a series of smaller tectonic plates and collision with the pacific plate from the marina islands, the philippines, tonga, in new zealand

That is the correct answer to the question, why is the southern portion of the ring of fire so complex?

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:

Answeris associated with sunny,dry weather;