Context: Recently, the Geological Agency of Indonesia has reported that a volcano has erupted from Mount Semeru.
About Mount Semeru

• It is a stratovolcano located in East Java, Indonesia containing an active Jonggring-Seloko vent at the Mahameru summit.
• It is located in the subduction zone, where the Indo-Australia plate subducts under the Eurasia plate.
• It is the highest mountain on the island of Java.
• It is also known as Mahameru, meaning "The Great Mountain" in Sanskrit.
• The name derived from the Hindu cosmology's mountain of Meru or Sumeru i.e. the abode of gods.

Pacific Ring of Fire

• The Ring of Fire, also referred to as the Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
• It traces boundaries between several tectonic plates—including the Pacific, Cocos, Indian-Australian, Nazca, North American, and Philippine Plates.
• The majority of Earth’s volcanoes and earthquakes take place along the Ring of Fire.
• The abundance of volcanoes and earthquakes along the Ring of Fire is caused by the amount of movement of tectonic plates in the area.
• The countries affected by it are Indonesia, the Philippines, Malaysia, Japan, Australia and New Zealand, Papua New Guinea, and other island nations like the Solomon Islands, Fiji, and many more in Melanesia, Micronesia and Polynesia.

Island Arcs

• They are long, curved chains of oceanic islands associated with intense volcanic and seismic activity and orogenic (mountain-building) processes.
• An island arc typically has a land mass or a partially enclosed, unusually shallow sea on its concave side.
• Along the convex side there almost invariably exists a long, narrow deep-sea trench.
• The greatest ocean depths are found in these depressions of the seafloor, as in the case of the Mariana (deepest trench in the world) and Tonga trenches.
• Prime examples of this form of geologic feature include the Aleutian-Alaska Arc and the Kuril-Kamchatka Arc.