News Excerpt:

Taiwan was hit by its biggest earthquake in at least 25 years on April 4. While Taiwan’s earthquake monitoring agency said the quake was 7.2 magnitude, the US Geological Survey (USGS) put it at 7.4.

About the news:

• The epicentre of the quake was located just 18 kilometres south-southwest of Hualien County, which is situated in eastern Taiwan.
• Taiwan is prone to earthquakes as it lies along the Pacific “Ring of Fire” — where 90% of the world’s earthquakes occur.
• According to the USGS, the island and its surrounding waters have registered about 2,000 earthquakes with a magnitude of 4.0 or greater since 1980 and more than 100 earthquakes with a magnitude above 5.5.
• Taiwan experiences earthquakes due to the interactions of two tectonic plates — the Philippine Sea Plate and the Eurasian Plate.

Ring of Fire:

• The Ring of Fire, also referred to as the Circum-Pacific Belt, is a string of hundreds of volcanoes and earthquake sites running along the Pacific Ocean.
• It is a semicircle or horseshoe in shape and stretches nearly 40,250 kilometres.
• It runs through around 15 countries, including the USA, Indonesia, Mexico, Japan, Canada, Guatemala, Russia, Chile, Peru, and the Philippines.
• According to a report by National Geographic, the Ring of Fire traces the meeting points of numerous tectonic plates, including the Eurasian, North American, Juan de Fuca, Cocos, Caribbean, Nazca, Antarctic, Indian, Australian, Philippine, and other smaller plates, which all encircle the large Pacific Plate.

Why is the Ring of Fire vulnerable to earthquakes?

• The Ring of Fire witnesses so many earthquakes due to constant sliding past, colliding into or moving above or below each other of the tectonic plates.
• As the edges of these plates are quite rough, they get stuck with one another while the rest of the plate keeps moving.
• An earthquake occurs when the plate has moved far enough, and the edges unstick on one of the faults.

Why are there so many volcanoes in the Ring of Fire?

• The existence of volcanoes in the Ring of Fire is also due to the movement of tectonic plates.
• Many volcanoes have been formed through a process known as subduction.
• It occurs when two plates collide, and the heavier plate is pushed under the other, creating a deep trench.
• When a ‘downgoing’ oceanic plate, such as the Pacific Plate, is pushed into a hotter mantle plate, it gets heated up and mixes with volatile elements.
• This process leads to the formation of magma, which rises up through the overlying plate and eventually erupts at the surface, forming volcanoes.
• Most of the planet's subduction zones are located in the Ring of Fire, which is why it hosts a large number of volcanoes.