Tsunami

• These are long-wavelength, long-period sea waves or tidal waves produced by the sudden or abrupt displacement of large volumes of water (including when an earthquake occurs at sea).
• A tsunami will only be triggered if the earthquake’s epicenter is located beneath ocean waters and the tremor’s magnitude is sufficiently large.

Effects of Earthquakes

• Ground shaking
• Differential ground settlement
• Land and mudslides
• Soil liquefaction
• Ground lurching
• Avalanches
• Ground displacement
• Floods from the dam and levee failures
• Fires
• Structural collapse
• Falling objects
• Tsunami

Global Warming and Earthquakes

• In recent research, geologists claim that global warming is one of the reasons for increased seismic activity.
• Reason:Melting glaciers and rising sea levels disrupt the pressure balance on Earth’s tectonic plates, leading to an increase in the frequency and intensity of earthquakes.

Distribution of Earthquakes

• The global distribution of earthquakes closely aligns with the locations of volcanoes.
• Regions of greatest seismicity are Circum-Pacific areas, with the epicentres and the most frequent occurrences along the “Pacific Ring of Fire”. It’s said that as many as 70% of earthquakes occur in the Circum-Pacific belt.
• Another 20% of the earthquakes take place in the Mediterranean-Himalayan belt including Asia Minor, the Himalayas and part of North-Western-China.

Recent earthquakes in news:

Earthquake in Turkey and Syria:

Recently, Turkey experienced powerful tremors after a 7.8 magnitude earthquake struck along the well-known Anatolia tectonic block.

• The earthquakes originated from relatively shallow depths and were classified as a “strike-slip quake.”
• This is considered Turkey’s most powerful earthquake in over a century and its worst disaster since the 1939 Erzincan Earthquake, which caused severe destruction in the Erzincan Plain and the Kelkit River Valley.

What Makes Turkey Prone to Earthquakes?

Turkey is highly prone to earthquakes due to several geological factors:

• Tectonic Plate Interactions: Turkey sits at the complex intersection of several tectonic plates, including the Eurasian Plate, African Plate, Arabian Plate, and Anatolian Plate.
• Anatolian Tectonic Plate: Turkey is predominantly located on the Anatolian Plate, which is squeezed between the Eurasian Plate to the north and the African and Arabian Plates to the south.
• Major Fault Lines: Two major fault lines pose significant seismic risk:
  • North Anatolian Fault (NAF): This fault runs across northern Turkey from west to east and marks the boundary between the Eurasian Plate and the Anatolian Plate. It is a right-lateral strike-slip fault responsible for large earthquakes.
  • East Anatolian Fault (EAF): Located in southeastern Turkey, it separates the Anatolian Plate from the northward-moving Arabian Plate. It is also capable of producing powerful earthquakes.
• Aegean Sea Plate: This smaller tectonic plate in the eastern Mediterranean Sea contributes to seismic activity in western Turkey and southern Greece.
• High Seismic Activity: Nearly 95% of Turkey’s land area is susceptible to earthquakes, with about one-third of the country classified as high-risk zones. This includes major cities like Istanbul, Izmir, and areas in East Anatolia.
• Historical Earthquakes: Turkey has a history of devastating earthquakes, such as the recent magnitude 7.8 earthquake which was the strongest in over a century, and the 1939 Erzincan earthquake. These events highlight the country’s vulnerability to seismic hazards.