Earthquake in Taiwan

What’s in today’s article?

• Why in News?
• What is Ring of Fire?
• Why is the Ring of Fire vulnerable to earthquakes?
• Why are there so many volcanoes in the Ring of Fire?
• Why is Taiwan so exposed to earthquakes?
• Preparedness of Taiwan

Why in News?

• Taiwan was hit by a 7.2 magnitude earthquake, the strongest in the last 25 years. 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 take place.

What is Ring of Fire?

• About
  • The Ring of Fire is essentially a string of hundreds of volcanoes and earthquake-sites which runs along the Pacific Ocean. 
  • It is a semicircle or horse shoe in shape and stretches nearly 40,250 kilometres.
• Numerous tectonic plates involved
  • The Ring of Fire traces the meeting points of numerous tectonic plates.
  • This includes the Eurasian, North American, Juan de Fuca, Cocos, Caribbean, Nazca, Antarctic, Indian, Australian, Philippine, and other smaller plates.
    • All these encircle the large Pacific Plate.
• Runs through various countries
  • It runs through 15 more countries including the USA, Indonesia, Mexico, Japan, Canada, Guatemala, Russia, Chile, Peru, and the Philippines.

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.
  • Taiwan experiences earthquakes due to the interactions of two tectonic plates — the Philippine Sea Plate and the Eurasian Plate.

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

• Many of the volcanoes have been formed through a process known as subduction. 
• It takes place when two plates collide with each other and the heavier plate is shoved under another, creating a deep trench.
  • Basically, when a ‘downgoing’ oceanic plate [like the Pacific 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,” which leads to the formation of volcanoes.
• Most of the subduction zones on the planet are located in the Ring of Fire and that’s why it hosts a large number of volcanoes.

Why is Taiwan so exposed to earthquakes?

• Location along the Pacific Ring of Fire
  • Taiwan lies along the Pacific Ring of Fire, the line of seismic faults encircling the Pacific Ocean where most of the world’s earthquakes occur.
• Interactions of two tectonic plates
  • The area is particularly vulnerable to temblors due to the tension accumulated from the interactions of two tectonic plates - the Philippine Sea Plate and the Eurasian Plate.
• Landscape
  • The region’s mountainous landscape can magnify the ground shaking, leading to landslides.

Preparedness of Taiwan

• Damage during recent earthquake
  • Recent earthquake in Taiwan measured 7.2, according to Taiwan’s earthquake monitoring agency, while the U.S. Geological Survey put it at 7.4.
  • It damaged several buildings in Hualien but caused only minor losses in the capital Taipei despite being strongly felt there.
  • The earthquake hit in the middle of the morning rush hour yet only slightly derailed the regular commute.
• Preparedness
  • The island has implemented strict building codes, a world-class seismological network, and widespread public education campaigns on earthquake safety.
  • The government continually revises the level of quake resistance required of new and existing buildings.
  • It also offers subsidies to residents willing to check their buildings’ quake resistance.
  • Taiwan also is pushing quake drills at schools and workplaces while public media and cellphones regularly carry notices about earthquakes and safety.

Q.1. What is Subduction in plate tectonics?

Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at convergent boundaries. 

Q.2. What is epicenter of an earthquake?

The epicenter of an earthquake is the point on the Earth's surface directly above the earthquake's hypocenter or focus. The hypocenter is the location below the Earth's surface where the earthquake begins.