Context:
The ground is shaking and swelling at Mauna Loa, the largest active volcano in the world, indicating that it could erupt. Scientists say they don’t expect that to happen right away but officials on the Big Island of Hawaii are telling residents to be prepared in case it does erupt soon.
Relevance:
GS I: Geography, Facts for Prelims
Dimensions of the Article:
- Where is Mauna Loa?
- Will Mauna Loa erupt like Kilauea?
- About the Ring of Fire
Where is Mauna Loa?
- Mauna Loa is one of five volcanoes that together make up the Big Island of Hawaii, which is the southernmost island in the Hawaiian archipelago.
- It’s not the tallest (that title goes to Mauna Kea) but it’s the largest and makes up about half of the island’s land mass.
- It sits immediately north of Kilauea volcano, which is currently erupting from its summit crater.
- Kilauea is well-known for a 2018 eruption that destroyed 700 homes and sent rivers of lava spreading across farms and into the ocean. Mauna Loa last erupted 38 years ago.
- In written history, dating to 1843, it’s erupted 33 times. The Big Island is mostly rural and is home to cattle ranches, coffee farms and beach resorts.
- It’s about 200 miles (320 kilometers) south of Hawaii’s most populous island, Oahu, where the state capital Honolulu and beach resort Waikiki are both located.
Will Mauna Loa erupt like Kilauea?
- Mauna Loa’s eruptions differ from Kilauea’s in part because it is taller.
- Its greater height gives it steeper slopes, which allow lava to rush down its hillsides faster than Kilauea’s.
- Its enormous size may allow it to store more magma, leading to larger lava flows when an eruption occurs.
- Mauna Loa has a much larger magma reservoir than Kilauea, which may allow it to hold more lava and rest longer between eruptions than Kilauea.
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
What is subduction?
- Subduction happens when tectonic plates shift, and one plate is shoved under another.
- This movement of the ocean floor produces a “mineral transmutation,” which leads to the melting and solidification of magma – that is, the formation of volcanoes.
- Basically, when a “downgoing” oceanic plate is shoved into a hotter mantle plate, it heats up, volatile elements mix, and this produces the magma.
- The magma then rises up through the overlying plate and spurts out at the surface.
-Source: Indian Express
