Context:
Recently, Mount Ibu erupted again, sending ash 4 km high, as streaks of purple lightning flashed around its crater.
Relevance:
GS I: Geography
Dimensions of the Article:
- Mount Ibu Overview
- Stratovolcano
- About the Ring of Fire
Mount Ibu Overview
About Mount Ibu:
- Location: An active stratovolcano situated along the northwest coast of Halmahera Island in Indonesia.
- Volcanic Activity: Part of a series of eruptions from various volcanoes across Indonesia.
- Indonesia is located on the Pacific “Ring of Fire,” a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur.
- The country has 127 active volcanoes.
Stratovolcano
- A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra.
- Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas.
- The lava flowing from stratovolcanoes typically cools and hardens before spreading far, due to high viscosity.
- The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma.
- Stratovolcanoes are sometimes called “composite volcanoes” because of their composite stratified structure built up from sequential outpourings of erupted materials.
- They are among the most common types of volcanoes, in contrast to the less common shield volcanoes.
- Two famous examples of stratovolcanoes are Krakatoa in Indonesia, known for its catastrophic eruption in 1883, and Vesuvius in Italy, whose catastrophic eruption in AD 79 buried the Roman cities of Pompeii and Herculaneum.
- In modern times, Mount St. Helens in Washington State, USA and Mount Pinatubo in the Philippines have erupted catastrophically, but with fewer deaths.
About the Ring of Fire
- Many volcanoes in the Ring of Fire were created through a process of subduction. And most of the planet’s subduction zones happen to be located in the Ring of Fire
- It is a string of at least 450 active and dormant volcanoes that form a semi-circle, or horse shoe, around the Philippine Sea plate, the Pacific Plate, Juan de Fuca and Cocos plates, and the Nazca Plate.
- There is a lot of seismic activity in the area.
- 90 per cent of all earthquakes strike within the Ring of Fire
Why are there so many volcanoes in the Ring of Fire?
- The tectonic plates move non-stop over a layer of partly solid and partly molten rock which is called the Earth’s mantle.
- When the plates collide or move apart, for instance, the Earth moves, literally.
- Mountains, like the Andes in South America and the Rockies in North America, as well as volcanoes have formed through the collision of tectonic plates.
- Many volcanoes in the Ring of Fire were created through a process of subduction. And most of the planet’s subduction zones happen to be located in the Ring of Fire
-Source: Indian Express