Description

Disclaimer: Copyright infringement not intended.

Context:

Indonesian officials called for the evacuation of 3,000 people living in six nearby villages due to the eruption of Mount Ibu volcano.

About Mount Ibu

Aspect	Details
Mount Ibu	A stratovolcano located on the island of Halmahera in the North Maluku province of Indonesia.
Stratovolcano Definition	A steep conical volcano made of layers of lava, ash, and volcanic debris.
Formation	Usually found on convergent plates and subduction zones.
Examples of Stratovolcanoes	Mount Vesuvius (Italy), Mount Fuji (Japan), Mount Krakatoa (Indonesia).
Other Volcanoes in Indonesia	Mount Lewotobi Laki-Laki: A double-layered volcano with a history of explosions.
	Mount Ruang: Has erupted multiple times, causing mass evacuations.
Indonesia’s Location	Lies along the Pacific Ring of Fire, making it prone to frequent volcanic and seismic activity.
Vulnerability	High vulnerability to volcanic eruptions due to its geotectonic setting.

About Stratovolcano

Feature	Details
Definition	Stratovolcanoes, also called composite volcanoes, are symmetrical, steep cones built from alternating layers of lava flows, volcanic ash, and other eruptive products.
Shape	Typically symmetrical with steep sides, unlike flat shield volcanoes.
Location	Commonly found above subduction zones and often part of volcanically active regions, such as the Ring of Fire.
Percentage of Volcanoes	Comprise approximately 60% of individual volcanoes on Earth.
Lava Composition	Made of viscous, sticky lava that does not flow easily, causing lava to accumulate around the opening.
Eruption Type	More likely to produce explosive eruptions due to the accumulation of gas in viscous magma.
Material	Composed of semi-lava and pyroclastic material, resulting in alternating layers.
Common Rock Type	Andesite is the most common type, but a variety of rocks can erupt under different tectonic conditions.
Summit Crater	Most have a summit crater containing a central vent or cluster of vents.

Volcanoes in Indonesia

Volcano Name	Type	Location	Last Eruption	Features
Mount Merapi	Stratovolcano	Central Java	2023	One of the most active volcanoes in the world; is frequent explosive eruptions.
Mount Tambora	Stratovolcano	Sumbawa	1967	Famous for the 1815 eruption, causing the "Year Without a Summer."
Mount Krakatoa	Stratovolcano	Sunda Strait (Between Java & Sumatra)	2022	Known for the 1883 eruption; Anak Krakatoa ("Child of Krakatoa") formed later.
Mount Bromo	Stratovolcano	East Java	2016	Part of the Tengger Caldera; popular for sunrise views and tourism.
Mount Rinjani	Stratovolcano	Lombok	2016	Second-highest volcano in Indonesia; features a crater lake (Segara Anak).
Mount Agung	Stratovolcano	Bali	2019	Sacred volcano for the Balinese; known for periodic eruptions.
Mount Sinabung	Stratovolcano	North Sumatra	2021	Recently reactivated after centuries of dormancy; frequent explosive eruptions.
Mount Semeru	Stratovolcano	East Java	2022	Highest volcano in Java; continuous activity with ash emissions.
Mount Ijen	Stratovolcano	East Java	1999	Famous for its blue flame phenomenon caused by sulfuric gas emissions.
Mount Toba	Supervolcano	North Sumatra	74,000 years ago	Site of a massive eruption; Toba caldera now houses Lake Toba, the largest volcanic lake.

READ ABOUT

Mount Ibu, a volcano on Indonesia's Halmahera island

Source:

THE HINDU

PRACTICE QUESTION

Q. Indonesia is home to some of the most active volcanoes in the world. Which of the following statements correctly describes the volcanic activity in Indonesia?

Indonesia is located on the Pacific Ring of Fire, making it prone to frequent volcanic eruptions.
Mount Merapi is the only active volcano in Indonesia with documented historical eruptions.
The eruption of Krakatoa in 1883 had global climatic effects, including a significant drop in global temperatures.
Indonesia's volcanoes are predominantly located in the western part of the archipelago with few active volcanoes in the eastern regions.

Select the correct answer using the code below:

(a) 1 and 3 only

(b) 2 and 4 only

(d) 1, 2, 3 and 4

Answer: a

Explanation:

Statement 1 is correct: Indonesia is located on the Pacific Ring of Fire which is why it is prone to frequent volcanic eruptions.

Statement 2 is incorrect: Mount Merapi is not the only active volcano in Indonesia; there are several others such as Mount Sinabung and Mount Bromo.

Statement 3 is correct: The eruption of Krakatoa in 1883 had global climatic effects including a significant drop in global temperatures.

Statement 4 is incorrect: Indonesia's volcanoes are spread across the entire archipelago including the eastern regions, such as Papua.