What Triggers Earthquakes? A Look at Their Origin, Epicenter, and Impact | TDG Explainer

People are sleeping at night or relaxing with their family and suddenly their world change with a sudden shake of the earth. It is a havoc situation which can not be avoided. Earthquake is disastrous phenomena which can not be fully understood even today despite we are fully equipped with modern and scientific technology. Science is still not able to find the right time of earthquake, however the prediction of rain, storm, tsunami are being forecasted and approximately are becoming true. Let’s have a look on the causes why earthquake occurs.

How Earthquakes Occur

Earthquakes happen when energy stored in the Earth’s crust is suddenly released, sending seismic waves through the ground. This energy buildup occurs due to the movement of tectonic plates, which constantly shift over the Earth’s mantle. When these plates collide, slide past each other, or pull apart, they create stress along fault lines. Eventually, when the stress surpasses the strength of the rocks, the fault slips, triggering an earthquake.

Key Stages of an Earthquake

1. Tectonic Plate Movements – The Earth’s crust consists of massive plates that move slowly over the mantle. Their interactions cause stress at plate boundaries.
2. Stress Accumulation – Over time, stress builds up along faults, bending the Earth’s crust under immense pressure.
3. Sudden Release of Energy – When rocks can no longer withstand the pressure, they break, releasing energy as seismic waves.
4. Seismic Waves Travel – These waves spread outward, shaking the ground and causing destruction. The point underground where the quake originates is called the focus, while the spot directly above it on the surface is the epicenter.
5. Aftershocks Follow – Smaller tremors occur as the crust continues to adjust, sometimes lasting for weeks or months.

Most earthquakes occur along tectonic plate boundaries, particularly in regions like the Pacific Ring of Fire, where plates frequently collide or shift.

What is the Epicenter?

The epicenter is the surface point directly above the earthquake’s focus. This location usually experiences the most intense shaking and damage. Scientists use data from multiple seismograph stations to determine the epicenter by analyzing the time and intensity of seismic waves.

Aftereffects of an Earthquake

Earthquakes can have severe and lasting consequences, including:

1. Aftershocks – Smaller tremors follow the main earthquake and can cause additional destruction.
2. Ground Shaking and Cracks – Strong quakes create intense vibrations, leading to structural damage in buildings, roads, and bridges.
3. Landslides and Avalanches – In mountainous areas, earthquakes can trigger massive landslides, blocking roads and burying settlements.
4. Tsunamis – Underwater earthquakes generate giant sea waves, which can flood coastal regions and cause catastrophic damage.
5. Liquefaction – Loose, water-saturated soil behaves like liquid, causing buildings to sink or collapse.
6. Fires and Explosions – Gas leaks, electrical malfunctions, and damaged pipelines often lead to fires and explosions.
7. Infrastructure Damage – Earthquakes severely impact transportation, communication, and power supply networks.
8. Economic Losses – Entire cities and industries suffer financial damage, leading to economic instability.
9. Casualties and Displacement – Thousands may die or become homeless, increasing the need for shelters and aid.
10. Health and Sanitation Issues – Disruptions in clean water, food supply, and medical services can lead to disease outbreaks.

The severity of these effects depends on factors such as the earthquake’s magnitude, depth, location, and a region’s level of preparedness.

Earthquake-Prone Areas Around the World

Some regions are more susceptible to earthquakes due to their location along tectonic boundaries. The most earthquake-prone areas include:

1. Pacific Ring of Fire – The most seismically active region, affecting:
   • Japan (Tokyo, Sendai, Kobe)
   • Indonesia (Sumatra, Java, Sulawesi)
   • Philippines
   • New Zealand (Wellington, Christchurch)
   • West Coast of North and South America (California, Chile, Peru, Mexico)
2. Himalayan Belt – A collision zone between the Indian and Eurasian plates, affecting:
   • India (Uttarakhand, Himachal Pradesh, Assam)
   • Nepal (Kathmandu)
   • Pakistan (Islamabad, Muzaffarabad)
   • Tibet
3. Alpide Belt – A seismic zone stretching from Europe to Asia, affecting:
   • Turkey (Istanbul, Izmir)
   • Iran (Tehran, Bam)
   • Greece (Athens, Crete)
   • Italy (Naples, Sicily)
4. San Andreas Fault (USA) – One of the most famous fault lines, impacting:
   • California (San Francisco, Los Angeles, San Diego)
5. Caribbean Region – High seismic activity in:
   • Haiti
   • Dominican Republic
   • Puerto Rico
6. Mid-Atlantic Ridge – Volcanic and seismic activity affecting:
   • Iceland
7. East African Rift – A continental rift causing seismic movements in:
   • Ethiopia, Kenya, Tanzania

These regions frequently experience earthquakes, making preparedness and earthquake-resistant infrastructure crucial.

Myanmar Earthquake – March 28, 2025

A devastating 7.7-magnitude earthquake struck central Myanmar near Mandalay on March 28, 2025, causing widespread destruction. A powerful 6.4-magnitude aftershock followed, leaving over 1,000 people dead, more than 2,300 injured, and at least 30 missing. The worst-hit regions, Sagaing and Mandalay, saw extensive damage to buildings, bridges, and infrastructure. Tremors reached neighboring Thailand and China, with Bangkok reporting the collapse of a 33-story building, killing at least six people.

In response, Myanmar’s military junta declared a state of emergency in six regions and appealed for international assistance. The United Nations allocated $5 million for immediate relief, while China, Russia, India, Malaysia, South Korea, and the United States extended aid despite ongoing geopolitical tensions. However, rescue efforts face major challenges due to destroyed roads, communication breakdowns, and Myanmar’s ongoing civil conflict, which has already displaced millions. The disaster has intensified concerns about the country’s ability to recover amid political instability.