Earthquake in Taiwan

11 Apr 2024 Earthquake in Taiwan

This article covers ‘Daily Current Affairs’ and the topic details of ”Earthquake in Taiwan”. This topic is relevant in the “Environment” section of the UPSC CSE exam.

Why in the News?

Taiwan experienced its most powerful earthquake in the past 25 years, registering a magnitude of 7.2. The epicentre of the seismic activity was pinpointed a mere 18 kilometres south-southwest of Hualien County, located in eastern Taiwan. This occurrence underscores Taiwan’s vulnerability to earthquakes due to its location along the Pacific “Ring of Fire.”

Reasons behind earthquakes in Taiwan

• Earthquakes are a frequent occurrence in Taiwan due to its location along the Pacific “Ring of Fire,” which accounts for around 90% of the world’s seismic activity. 
• This ring comprises a network of seismic faults encircling the Pacific Ocean, where the majority of earthquakes globally take place. Taiwan’s vulnerability to earthquakes is exacerbated by the dynamic interaction of the Philippine Sea Plate and the Eurasian Plate, which accumulate tension and periodically release it through seismic events.
• The mountainous terrain of Taiwan can intensify ground shaking, leading to landslides. Recent incidents in Taiwan’s eastern coast, close to the epicentre, saw landslides triggered by falling debris, resulting in the destruction of tunnels and highways, along with casualties from crushed vehicles.

About the Pacific Ring of Fire

• Alternatively referred to as the Pacific Rim or the Circum-Pacific Belt, denotes a region encircling the Pacific Ocean distinguished by active volcanoes and recurrent seismic activity. 

Boundaries of Pacific Ring of Fire

• This area encompasses approximately 40,000 kilometres and delineates the boundaries between several tectonic plates, including the Pacific, Juan de Fuca, Cocos, Indian-Australian, Nazca, American, and Philippine Plates. 
• Its trajectory spans along the western coast of South and North America, traverses the Aleutian Islands in Alaska, extends down the eastern coast of Asia, passes New Zealand, and culminates at the northern coast of Antarctica. The Ring of Fire hosts roughly 75% of the world’s volcanoes, with approximately 90% of global earthquakes occurring within its confines.

Volcanic activities in the region

• The volcanic activity within the Ring of Fire arises from the movement of tectonic plates converging, leading to the creation of subduction zones where one plate is forced beneath another. 
• This process occurs gradually, with plates shifting merely one or two inches per year. As subduction transpires, rocks undergo melting, transforming into magma that ascends to the Earth’s surface, instigating volcanic eruptions.
• The Ring of Fire harbours a significant concentration of volcanoes primarily because the majority of the planet’s subduction zones are situated within its bounds. Particularly noteworthy are the volcanoes in Indonesia, renowned for their high activity levels within the Pacific Ring of Fire. These volcanic formations stem from the interaction of three principal active tectonic plates: the Eurasian Plate, Pacific Plate, and Indo-Australian Plate, which undergo subduction processes in this region.                                                                                                                                                 

Cooling Patterns in the Pacific Plate

• Recent scientific studies have illuminated the cooling trend observed in the Pacific Plate, which significantly influences the tectonic dynamics within the Ring of Fire. This cooling phenomenon may impact plate boundaries and subduction zones, potentially altering mountain-building processes. 
• Researchers have discerned that the younger segments of the Pacific Plate, approximately 2 million years old, are cooling at an accelerated pace compared to older sections, around 100 million years old. This cooling process could heighten stress accumulation along plate boundaries, potentially leading to increased frequency and intensity of earthquakes.
•  Notably, the most active regions within the Ring of Fire coincide with the northern and western extents of the Pacific Plate, where the younger portions are predominant.

About volcanism

• Volcanism encompasses the eruption of molten rock, ash, and gases from beneath the Earth’s crust onto its surface or into the atmosphere.
• It occurs in various types of volcanoes, including stratovolcanoes, shield volcanoes, and cinder cone volcanoes, each with distinct characteristics and eruption styles.

Causes of Volcanism

• Tectonic Activity: Volcanic eruptions often result from the movement and interaction of tectonic plates. Subduction zones are the regions where one tectonic plate is forced beneath another. It is the common sites of volcanic activity.
• Hotspots: Some volcanic eruptions are caused by hotspots, areas where magma from the mantle rises to the surface, creating volcanic features such as islands or volcanic chains.

Types of Volcanoes

• Stratovolcanoes: Tall, steep-sided volcanoes characterised by explosive eruptions of viscous magma.
• Shield Volcanoes: Broad, gently sloping volcanoes formed by the eruption of low-viscosity lava flows.
• Cinder Cone Volcanoes: Small, steep-sided cones composed of volcanic fragments ejected during explosive eruptions.

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Prelims practise questions

Q1. Which of the following best describes a stratovolcano?

(a) A broad, gently sloping volcano formed by the eruption of low-viscosity lava flows.

(b) A small, steep-sided cone composed of volcanic fragments ejected during explosive eruptions.

(c) A tall, steep-sided volcano characterised by explosive eruptions of viscous magma.

(d) A volcano formed by the accumulation of volcanic ash and debris around a central vent.

Answer: C

Q2. Consider the following statements:

(a) Basic lava tends to have a lower content of Acidic lava

(b) Tephra is the term used for the solidified remains of lava flows and other volcanic material

(c) The San Andreas Fault in California is an example of a Subduction zone

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Answer: A

Mains practise question

Q1. Analyse the role of hotspot volcanoes in the creation of island chains, such as the Hawaiian-Emperor seamount chain. How does the movement of tectonic plates over stationary hotspots lead to the sequential formation of volcanic islands?

Himanshu Mishra

I am a content developer and have done my Post Graduation in Political Science. I have given 2 UPSC mains, 1 IB ACIO interview and have cleared UGC NET JRF too.