Complex sentence: Barren Island is an island located in the Andaman Sea, dominated by Barren Volcano, the only confirmed active volcano in South Asia, and the only active volcano along a chain of volcanoes from Sumatra to Myanmar.
Split into simpler sentences: Barren Island is an island located in the Andaman Sea, dominated by Barren Volcano, the only confirmed active volcano in South Asia. And the only active volcano along a chain of volcanoes from Sumatra to Myanmar.