Earthquakes: causes and effects

Earthquakes: Causes and Effects

Introduction:
Earthquakes are one of the most devastating natural disasters that occur globally. The earthquake is an abrupt and sudden shaking of the earth’s surface that results from the release of energy stored in the earth’s crust. The intensity and magnitude of an earthquake determine the damage it can cause.

Key Concepts:

1. Causes of Earthquakes:
   Earthquakes can be caused by various natural and human-induced factors, such as:

   • Tectonic plate movement – Plates that make up the earth’s surface move and collide, creating stress and pressure. When the energy is released in the form of seismic waves, it causes an earthquake.
   • Underground activity – Volcanic eruptions, landslides, and explosions also can trigger an earthquake by shaking the earth’s crust.
   • Human activities – Human activities, such as mining, water reservoirs, and oil extraction, can also cause an earthquake by destabilizing the earth’s crust.

2. Effects of Earthquakes:
   The effects of an earthquake can be widespread and catastrophic, including:

   • Loss of lives and human injuries
   • Infrastructure damage and destruction of buildings
   • Disruption of transportation systems
   • Tsunamis and landslides
   • Economic losses and increased poverty

Equations and Formulas:
The Richter Scale measures the magnitude or strength of an earthquake, based on the seismic waves’ amplitude. The formula for the Richter Scale is:
Magnitude = log10 (Maximum seismic wave amplitude in microns) – log10 (Amplitude of a standard seismograph)

Examples:
Some of the most significant earthquakes in history include:

• The 2011 earthquake in Japan, which led to a tsunami, killed more than 15,000 people, and caused around $235 billion in damages.
• The 2004 Indian Ocean earthquake, which had a magnitude of 9.1-9.3, triggered one of the most devastating tsunamis in history, killing approximately 230,000 people.

References:

1. "The Science of Earthquakes." USGS, www.usgs.gov/natural-hazards/earthquake-hazards/science-earthquakes.
2. "Earthquake: Causes, Effects, and Precautionary Measures." ScienceDirect, www.sciencedirect.com/science/article/pii/S2093791117302147.