Earthquakes: Disasters explained

Earthquakes, also known as seismic events, occur across the world every day. Most of them are too small to cause any damage.

Yet powerful earthquakes – like the ones that recently hit Türkiye and Syria – can hit hard. And when they do, they claim thousands of lives. Major earthquakes can also trigger tsunamis and other disasters, making them even more devastating.

Discover everything you need to know about earthquakes here.

KEY FACTS AND FIGURES

Earthquakes FAQs

What is an earthquake and how are they caused?

What are the impacts of an earthquake?

How does ShelterBox help?

To understand what causes an seismic event, it’s important to know what tectonic plates are and how they work.

Tectonic plates cover the surface of the earth. They are slow-moving, but they get stuck at their edges due to friction. And when the stress on the edge overcomes the friction, there is an earthquake. This releases energy in waves that travel through the earth’s crust and cause the shaking that we feel.

We call the point underground, where the force builds, the focus. As the strength of the force varies, so do the scale of the quakes. And that’s why some are a lot more damaging than others.

An earthquake can trigger secondary hazards or disasters, that sometimes cause far more harm. This includes landslides, tsunamis and flooding.

An earthquake can be a scary and traumatic event for a person to experience. Here are some of the impacts that a disaster like this can have.

Aftershocks

Aftershocks are smaller quakes that happen after the largest shock of an earthquake sequence. They can continue over a period of weeks, months, or years. Most powerful mainshocks cause further larger, longer and many more aftershocks.

Liquefaction

Liquefaction is a physical process that can lead to ground failure. It causes clay-free soil deposits, like sands and silts, to temporarily lose their ‘solid’ strength. Thus they behave as thick fluids rather than as solids. The effect is very much like when you wiggle your toes in the sand close to the water.

Tsunamis

A tsunami is a series of giant waves caused by earthquakes or undersea volcanic eruptions.

It sends a surge of water onto land, often reaching heights of over 100 feet. Although tsunami waves do not reach great heights out in the depths of the ocean, as they enter shallower water they begin to grow in energy and height.

Tsunami waves can tear across the sea at speeds of 500 miles an hour. The depth of the ocean determines the speed – travelling as fast as a jet plane over deep waters and slowing down when reaching shallow waters.

Landslides

A landslide is the movement of a mass of rock, debris, or earth down a slope.

We have responded many times to major earthquakes and tsunamis. Here are some examples:

• Gujarat, India, 2001
• Indian Ocean tsunami, 2004, supporting families in Indonesia
• Haiti, 2010.
• Tohoku earthquake and tsunami, Japan, 2011
• Nepal, 2015.
• Lombok and Sulawesi earthquakes and tsunami, Indonesia, 2018
• Mindanao, Philippines, 2019
• Haiti, 2021

Right now, we are supporting people affected by the recent earthquakes in Turkey and Syria.