Earthquake in Turkey

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    In Context

    • Recently, three earthquakes measuring 7.8, 7.6, and 6.0 magnitude on the Richter scale hit wide swaths of Turkey and neighbouring Syria.

    More about the news

    • Epicentre:
      • The epicentre was about 26 km east of the Turkish city of Nurdagi at a depth of about 18 km on the East Anatolian Fault. 
      • The quake radiated towards the northeast, bringing devastation to central Turkey and Syria.
    • Damage:
      • This is the strongest earthquake to shake the region in more than 100 years. 
      • It has killed at least 3,800 people across Turkey and Syria.
    • Vulnerability of the region:
      • The area has many buildings constructed of brittle concrete (which makes them prone to cracking, spalling, loss of strength, or steel corrosion), making them “extremely vulnerable to earthquake shaking.

    Earthquake

    • It is the shaking of the surface of the Earth which results in a sudden release of energy in the Earth’s lithosphere (rocky outer part of the Earth) that creates seismic waves.
    • Earthquakes can cause severe damage, particularly in an area where homes and other buildings are poorly constructed and landslides are common.
    • An earthquake’s point of initial rupture is called its hypocenter or focus. 
    • The epicentre is the point at ground level directly above the hypocenter.
    • It is measured in the Richter scale.

    Plate Tectonic Theory/Plate Tectonic

    • Plate tectonic theory had its beginnings in 1915 when Alfred Wegener proposed his theory of “continental drift. 
    • According to the Plate Tectonic theory, Earth has a rigid outer layer, known as the lithosphere, which is typically about 100 km (60 miles) thick and overlies a plastic (moldable, partially molten) layer called the asthenosphere. 
    • The lithosphere is broken up into:
      • seven very large continental- and ocean-sized plates,
      • six or seven medium-sized regional plates, and 
      • several small plates. 
    • These plates move relative to each other.
      • They typically move at rates of 5 to 10 cm (2 to 4 inches) per year, and interact along their boundaries.
      • They converge, diverge, or slip past one another. 

    • Outcomes:
      • Responsible for Earthquakes:
        • Such interactions are thought to be responsible for most of Earth’s seismic and volcanic activity, although earthquakes and volcanoes can occur in plate interiors.
      • Mountain formation:
        • Plate motions cause mountains to rise where plates push together or converge. 
      • Ocean formation:
        • Continents fracture and oceans are formed where plates pull apart or diverge.

    Reasons of Turkey’s Earthquakes

    • Turkey’s proneness to earthquakes:
      • Turkey is frequently shaken by earthquakes. 
        • In 2020 itself, it recorded almost 33,000 earthquakes in the region, according to Disaster and Emergency Management Authority (AFAD). 
        • Out of these, 332 earthquakes were of magnitudes 4.0 and higher. 
      • Turkey’s proneness to earthquakes comes from its tectonic location.
        • According to one estimate, almost 95% of the country’s land mass is prone to earthquake.
        • About a third of the country is at high risk, including the areas around the major cities of Istanbul and Izmir and the region of East Anatolia.  
    • Significance of location:
      • Anatolian tectonic plate:
        • Turkey is located on the Anatolian tectonic plate, which is wedged between the Eurasian and African plates. 
        • On the north side, the minor Arabian plate further restricts movement. 
      • North Anatolian fault (NAF) line:
        • One fault line — the North Anatolian fault (NAF) line, the meeting point of the Eurasian and Anatolian tectonic plates — is known to be “particularly devastating”. 
        • The NAF, one of the best-understood fault systems in the world, stretches from the south of Istanbul to northeastern Turkey, and has caused catastrophic earthquakes in the past.
      • East Anatolian fault line:
        • Then there is the East Anatolian fault line, the tectonic boundary between the Anatolian Plate and the northward-moving Arabian Plate. 
        • It runs 650 kilometers from eastern Turkey and into the Mediterranean. 
      • Aegean Sea Plate:
        • In addition to this, the Aegean Sea Plate, located in the eastern Mediterranean Sea under southern Greece and western Turkey, is also a source of seismic activity in the region. 

     

    Damage to the ancient historical sites

    • Gaziantep Kalesi:
      • The historic 2,200-year-old stone castle sitting atop a hill in the centre of Gaziantep. 
      • Known locally as Gaziantep Kalesi, the historic stone castle was first constructed as an observation point by the Hittite Empire during the second millennium BC.
        • For over 2,000 years, Gaziantep Castle stood strong, its structure remaining intact despite waves of invasion and conquest that saw it controlled by a series of Middle Eastern empires.
      • It is the most famous landmark of Gaziantep which was used as an observation point during Roman times – has been damaged, with its walls and watch towers disintegrated. 
    • Yeni Mosque:
      • One of the most prominent sites in Maltaya, the famous Yeni Mosque which dates back to the 13th century, has collapsed due to the earthquake. 

    Source: TH

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