An earthquake

An earthquake

An earthquake is a sudden vibration or shaking that occurs in the upper layer of the earth. This vibration is caused by

• natural forces from the waves passing within layers of rocks under the ground. When rocks under the earth's surface move towards each other they often cause tension and friction. This process eventually causes a rupture that releases a vibration energy. In turn, this energy causes sudden vibrations in the upper layer of the earth. This is what is called an earthquake.
• Earthquakes can also be caused by volcanic eruptions and human activities such as nuclear explosions and mining.

Effects of earthquakes

Earthquakes have various effects on the environment. Although they last for only a few seconds, earthquakes may cause devastating effects. The effects of earthquakes depend on the magnitude of the quake, strength of the buildings or any other infrastructure, and the geological nature of the area affected by the earthquake.

The following are some of the effects of earthquakes

1. Destruction of environment and settlements: When an earthquake occurs, it causes rocks to crack which may result in destruction of infrastructures such as roads, railways and sports grounds. Earthquakes may also cause collapse of buildings such as schools, hospitals and settlements. For example, Kagera and Katavi Regions in Tanzania experienced earthquakes in 2016 and 2019, respectively. The earthquakes destroyed infrastructure including roads, school buildings, hospitals and settlements;
2. Outbreak of diseases: Earthquakes can cause damage to sewage systems. The damaged sewage system may discharge waste water that contaminates clean water systems. When human beings use contaminated water for cooking, drinking, bathing and cleaning utensils, they are likely to be affected by waterborne diseases such as typhoid, cholera and diarrhoea. Likewise, earthquakes may cause introduction of dust and toxic fumes into the atmosphere. This condition can lead to eye diseases and respiratory problems;
3. Outbreak of fire: When earthquakes damage electrical infrastructure, cause volcanic eruption or rock collision, fire may erupt. When that happens, it becomes very difficult to control fire outbreak as fire fighters can hardly reach the affected areas due to the damage of infrastructure;
4. Occurrence of Tsunami: Earthquakes can cause large waves in the ocean called tsunamis. These waves travel at high speed to the shores where they may cause devastation to human beings, animals and property;
5. Changes in the ocean depths: Earthquakes may cause the ocean floor to shake, which subsequently results into movement or rupturing of the oceanic floor rocks. This condition can lead to spread of volcanoes that eventually solidify and reduce the depth of the ocean. In addition, an earthquake can cause bed-rocks along the ocean floor to experience tensional forces, develop faults and sink further into the crust. This is likely to increase the depth of the ocean in the affected area; and
6. Death of living things: Earthquakes have often caused deaths to humans and other living things. When an earthquake occurs, it can destroy buildings and damage infrastructure. When debris falls on people or animals it can cause death.

Some of the effects of an earthquake

Precautions to reduce the effects of an earthquake

1. Education: Teach people of all ages, including those with special needs, how to reduce earthquake impacts.
2. Awareness: Use media and stakeholders to educate communities about earthquake risks, high-risk areas, and safety measures.
3. Earthquake-Resistant Buildings: Encourage constructing houses that can withstand earthquakes.
4. Land Use Planning: Assess land before allocating it for settlement to avoid high-risk areas.
5. Safety During Earthquakes:
   • Stay away from tall buildings, trees, electrical poles, beaches, and riverbanks.
   • If indoors, take cover under a table or bed and protect your head and body with heavy clothing.
6. After an Earthquake:
   • Call for help if needed.
   • Move to open spaces like playing fields or farms to stay safe.