Severe Earthquake Disaster in Taiwan

Severe Earthquake Disaster in Taiwan

GS-1: Disaster (Physical Geography)

(IAS/UPPCS)

 

 

Relevant for Prelims:

Important geophysical phenomena like earthquake, tsunami, volcano, cyclone, ring of fire, seismograph, Richter scale, Markley scale.

Relevant for Mains:

Severe Earthquake Disaster in Taiwan - Key Points, Causes, Causes of Volcanism in the Ring of Fire, Social, Economic and Environmental Impacts of Earthquake.

 

05/04/2024

Source: The Hindu

Why in news:

Recently, the eastern part of Taiwan experienced the strongest earthquake of magnitude 7.4 in almost 25 years.

  • Earlier, an earthquake of 7.6 magnitude had occurred in Taiwan in September 1999. The first earthquake in Taiwan was recorded in the year 1624.

Key points related to the Disaster:

Earthquake intensity:

  • According to the US Geological Survey (USGS), the intensity of this earthquake was 7.4, while Taiwan's earthquake monitoring agency measured the intensity of this earthquake at 7.2.

Epicenter of the earthquake:

  • The epicenter of this earthquake was located at a depth of 34.8 kilometers, 18 kilometers (11 mi) south of Hualien County city of Taiwan, which is located in eastern Taiwan.

Impact:

  • 9 people died and more than 800 people were injured in this earthquake disaster.
  • Due to this earthquake, earthquake tremors were also felt in some parts of Japan.
  • After this earthquake, a tsunami warning was issued in some parts of southern Japan.

Causes of earthquake disaster in Taiwan:

  • Taiwan has a long history of earthquakes due to its location in the 'Pacific Ring of Fire'.
  • The 'Pacific Ring of Fire' is a belt of seismic faults encircling the Pacific Ocean, where most of the world's earthquakes occur.
  • Proximity to the Pacific Ring of Fire: Taiwan is prone to earthquakes because it lies along the Pacific "Ring of Fire" where 90% of the world's earthquakes occur.
  • Earthquakes in Taiwan are caused by the interaction of tectonic plates – the Philippine Sea Plate and the Eurasian Plate and the Sunda Plate.

About Ring of Fire:

  • The Ring of Fire, also known as the Circum-Pacific Belt. It is basically a chain of hundreds of volcanoes and earthquakes that run along the Pacific Ocean.
  • This chain is like a semicircle or horseshoe in shape and extends for about 40,250 kilometers.
  • The Ring of Fire straddles the meeting points of several tectonic plates, including the Eurasian, North American, Juan de Fuca, Cocos, Caribbean, Nazca, Antarctic, Indian, Australian, Philippine, and other smaller plates.
  • The Ring of Fire passes through 15 more countries, including the United States, Indonesia, Mexico, Japan, Canada, Guatemala, Russia, Chile, Peru and the Philippines.

Causes of volcanoes to appear in the Ring of Fire:

  • Volcanoes in the Ring of Fire also occur due to the movement of tectonic plates.
  • Subduction of plates: Many volcanoes are formed through a process called subduction.
  • In this process, when two plates collide, the heavier plate is pushed beneath the other plate, resulting in a deep trench.
  • This process involves the subduction of an oceanic plate such as the Pacific Plate into a hotter mantle plate.
  • Production of Magma: As the oceanic plate is pushed deeper, it heats up and volatile elements mix with it, resulting in the production of magma.
  • This magma then rises through the upper plate and erupts on the surface, forming volcanoes.
  • The Ring of Fire, where most subduction zones are concentrated, is home to a large number of volcanoes due to this process.

About Earthquake:

  • Earthquake means vibration of the earth. The vibration that is created due to the propagation of seismic waves around the earth due to the energy generated due to endogenous and exogenous forces is called earthquake.
  • Epi-centre: The place where seismic waves are first felt is called epi-centre. The earthquake epicenter is just above the earthquake focus.

Measurement of Earthquake:

  • At present, earthquakes are measured on the basis of two scales – 1. Mercalli scale and 2. Richter scale.
  • Richter scale: It is an instrument used to measure the intensity of earthquakes.
  • Markelli scale: This instrument is used to record the intensity of earthquake.
  • Seismograph: Seismic waves are recorded on this instrument.

Causes for the origin of earthquake:

  • This is a sudden vibration occurring on the earth's surface. Its origin occurs naturally below the earth's surface (underground).
  • Its origin can be due to both natural and human reasons.
  • Natural causes include volcanic activity, plate tectonic events and expansion of geological gases etc.
  • Artificial or man-made earthquakes occur due to unscientific human activities.
  • Before an earthquake, the amount of 'radon' gases in the atmosphere increases.
  • The place where the quantity of this gas increases, there is a sign of earthquake.

Causes of Earthquake:

  • Earthquakes occur due to the collision of tectonic plates inside the Earth.
  • There are seven plates inside the Earth which keep rotating continuously. When these plates collide at some place, a fault line zone is formed there and the edges of the surface bend. Due to bending of the surface, pressure builds up there and the plates start breaking. Due to the breaking of these plates, the earth energy inside comes out and the earth starts vibrating, this vibration is called earthquake.
  • Earthquakes occur due to the collision of tectonic plates inside the Earth.
  • There are seven plates within the Earth which keep rotating continuously. When these plates collide at some place, a fault line zone is formed there and the edges of the surface bend. Due to bending of the surface, pressure builds up there and the plates start breaking. Due to the breaking of these plates, the earth energy inside comes out and the earth starts vibrating, this vibration is called earthquake.

Types of earthquake:

  • Tectonic earthquake: This is the most common form of earthquake. This is caused by the movement of plates in the Earth's interior, called tectonic plates.
  • Volcanic earthquake: This type of earthquake is slightly more intense than the tectonic earthquake. These types of earthquakes occur before or after volcanic eruptions.
  • Brief earthquake: This type of earthquake occurs due to pressure generated within the rocks in underground mines.
  • Explosive earthquake: It is a type of earthquake of artificial nature, which occurs due to human activities, such as nuclear explosion.

World Distribution of Earthquake:

  • There is a kind of relationship in the world distribution of areas affected by earthquakes and volcanism on the earth's surface, because both are related to the endogenous ground movement occurring in the earth's crust.
  • The distribution of earthquakes on the earth's surface is found in areas spread in the form of belts, which are called earthquake belts.
  • Among the main earthquake belts, 1. Circum-Pacific Ocean Belt, 2. Central Atlantic Belt and 3. Central Continental Belt are most important.

Earthquake areas in India:

  • The Indian subcontinent is divided into four seismic zones II, III, IV and V.
  • According to government data, about 54% of India's area is affected by earthquakes. Zone 5 has the highest risk of earthquakes while Zone 2 is a much lower risk area.

Social, economic and environmental Impacts of earthquake:

  • The following effects can be seen due to earthquake:
    • Earthquakes increase the likelihood of landslides and avalanches. Incidents of landslides and avalanches have been seen in Uttarakhand.
    • There is a danger of flood due to breaking of big dams due to earthquake.
  • Earthquakes are also considered responsible for tragedies like tsunami. Tsunami outbreak has been seen in many countries like India, Japan, Sri Lanka.
  • Earthquakes completely destroy infrastructure, such as buildings, residential areas, roads, railway tracks, bridges, etc.
  • Earthquakes are destructive, causing huge loss of life and property, depending on the intensity.
  • Earthquakes cause unexpected high waves (tides) in the oceans, causing severe flooding in coastal areas.

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Mains Question:

What is the Ring of Fire? Explain the causes of volcanic eruptions in the Ring of Fire.

Earthquakes keep happening all over the world every day. Throw light on the cause of earthquake and its social, economic and environmental impacts.