Question

Why dose the barren island becoming conical in shape?

Answer 1

Volcanic cones are simple volcanic landforms. They are formed when the ejecta from the volcanic vent piles up in the shape of a cone around the vent of the volcano. Different types of volcanic cones are formed on the basis of the size and nature of the fragments which are ejected at the time of eruption. They are stratocones, tuff cones, cinder cones, and spatter cones.

The Barren Island is dominated by the Barren Volcano which is a Stratovolcano with pyroclastic cones. This is an active volcano and has erupted nearly 10 times. The most recent eruption took place in January 2017. Every time an eruption takes place a lot of lava comes out and settles around the vent. So the cone shape becomes bigger. 

Answer 2

due to frequent eruptions