An earthquake is the shaking of the Earth’s surface caused by a sudden release of energy in the Earth’s lithosphere, which generates seismic waves. Earthquakes can range in size from those that are so small that they are not felt to those that are powerful enough to propel objects and people into the air and wreak havoc on entire cities. The seismicity, or seismic activity, of a region is defined as the frequency, type, and magnitude of earthquakes experienced over a given time period. PowerPAC plus will show you more!!!
Type of earthquakes
There are four different types of earthquakes: tectonic, volcanic, collapse and explosion.
- A tectonic earthquake occurs when the earth’s crust ruptures as a result of geological forces acting on rocks and adjoining plates, causing physical and chemical changes.
- A volcanic earthquake is defined as any earthquake caused by tectonic forces associated with volcanic activity.
- A collapse earthquake is a small earthquake that occurs in underground caverns and mines as a result of seismic waves produced by the surface explosion of rock.
- An explosion earthquake occurs as a result of detonation of nuclear or chemical device
The tectonic plates that make up the earth’s crust are constantly shifting. As the edges of these plates slide against each other in fault zones, friction slows them down, causing pressure to build up over time. When the force of movement finally overcomes the friction, sections of the crust break or shift, releasing pent-up pressure in the form of seismic waves. This is a naturally occurring earthquake, also known as a tectonic earthquake.
How to protect yourself when earthquakes occur?
If you are inside, stay inside.
- Take the following precautions to reduce your chances of being injured:
- If possible, move away from glass, hanging objects, bookcases, china cabinets, or other large furniture that could fall within a few seconds before shaking intensifies. Keep an eye out for falling objects such as bricks from fireplaces and chimneys, light fixtures, wall hangings, high shelves, and cabinets with swinging doors.
- Grab something nearby to protect your head and face from falling debris and broken glass.
- If you’re in bed, hold on and stay there, using a pillow to protect your head. You are less likely to be injured if you stay where you are.
If you are in a high-rise building, drop, cover, and hold on.
- Remove yourself from windows and outside walls.
- Continue to stay in the building.
- USE THE ELEVATORS AT YOUR OWN RISK. The power may go out, and the sprinkler systems may activate.
- Stay calm if you’re trapped. Tap on hard or metal parts of the structure to get someone’s attention. This may improve your chances of being rescued.
If you are inside a crowded place, drop, cover, and hold on.
- Do not rush for the exits. Others will have the same thought.
- Keep a safe distance from display shelves containing potentially hazardous objects.
- Take cover and grab something to shield your head and face from falling debris and glass if you can.
If you are outside, stay outside.
- Keep a safe distance from structures, utility wires, sinkholes, and fuel and gas lines. The greatest danger from falling debris is just outside doorways and close to building exterior walls.
- Locate an open space free of trees, telephone poles, and buildings. Once you’re out in the open, get low and stay there until the shaking stops.
- The area closest to a building’s exterior walls is the most dangerous. Windows, facades, and architectural details are frequently the first components of a building to fail. Keep away from this dangerous area.
If you are in a moving vehicle, stop as quickly and safely as possible.
- Drive to the shoulder or the curb, away from utility poles, overhead wires, and under- or overpasses.
- Stay in the vehicle and apply the parking brake. A car’s springs may jiggle violently, but it’s a safe place to be until the shaking stops.
- Turn on the radio to listen to emergency broadcasts.
- Stay inside if a power line falls on your car until a trained person removes the wire.
- When it is safe to resume driving, keep an eye out for hazards caused by the earthquake, such as potholes, downed utility poles and wires, rising water levels, fallen overpasses, or collapsed bridges.
If you are near the shore, drop, cover, and hold on until the shaking stops.
- If there is severe shaking for more than 20 seconds, immediately evacuate to high ground because the earthquake may have caused a tsunami.
- Move 2 miles (3 kilometers) inland or to land at least 100 feet (30 meters) above sea level right away. Don’t wait for the government to issue a warning.
- To avoid traffic, debris, and other hazards, walk quickly rather than drive.
If you cannot drop to the ground, try to sit or remain seated so you are not knocked down.
- If you’re in a wheelchair, make sure your wheels are locked. Remove anything that isn’t securely fastened to the wheelchair.
- Use a large book, a pillow, or your arms to protect your head and neck. The goal is to avoid injuries caused by falling or by objects that may fall or be thrown at you.
- If you can, seek refuge beneath a sturdy table or desk. Avoid exterior walls, windows, fireplaces, and hanging objects.
- If you are unable to move from a bed or chair, cover yourself with blankets and pillows to protect yourself from falling objects.
Top 9 worst earthquake
The Shaanxi earthquake is regarded as the deadliest in history. On January 23, 1556, it occurred in the northwestern Shaanxi province (formerly Shensi). The 8-magnitude quake is estimated to have killed 830,000 people. The quake destroyed approximately 840 kilometers of the area, killing nearly 60 percent of the region’s population.
The second-deadliest earthquake occurred in China as well. On July 28, 1976, the Tangshan quake struck the industrial city of Tangshan, causing the most casualties in the previous century. The 7.8-magnitude earthquake killed 255,000 people and injured 800,000 more. The earthquake destroyed nearly 180 buildings in less than 10 seconds, causing damage as far away as Beijing.
On October 11, 1138, the third-deadliest earthquake in history struck the northern Syrian Aleppo province. More than 230,000 people were killed. The quake’s magnitude is unknown.
A 9.1-magnitude earthquake struck Indonesia’s island of Sumatra, affecting 14 countries along the Indian Ocean’s South Asian and African coasts. In Indonesia, the quake and subsequent tsunami killed over 227,000 people and 50,000 disappeared. Approximately 1.7 million people were displaced.
This magnitude 7 earthquake in Haiti killed approximately 222,000 people and injured over 300,000 more. The earthquake displaced 1.3 million people and destroyed nearly 100,000 homes.
The 7.9-magnitude earthquake that struck Iran’s northeast Semnan province in the Damghan region killed over 200,000 people. The sixth-deadliest earthquake in Iranian history claimed the most lives.
On December 16, 1920, it occurred in Haiyuan County, Ningxia Province, China. More than 200,000 people were killed in the Ganyanchi earthquake, as it is also known.
On March 23, 893, a devastating earthquake struck the Iranian city of Ardabil. More than 150,000 people were killed.
The Kanto earthquake was the most deadly in Japanese history. The 7.9-magnitude earthquake killed 142,000 people and caused widespread devastation in the Tokyo-Yokohama area. More than 380 houses were also destroyed by the earthquake.
In recent years, the world has seen a number of earthquakes. Earthquakes have occurred in Chile, Haiti, Japan, and New Zealand, among other places. And they all had a high impact on people and their lives (physically, economically, environmentally, and socially). Humans in such affected areas are experiencing the greatest shock of their lives, and they require outside assistance. As a result, assistance in the form of temporary shelter, food, safe drinking water, and various types of medicines is required.