What is a geohazard?
A geohazard is a natural event caused by processes inside or on the Earth that can harm people, buildings and the environment. The Earth's crust is broken into large pieces called tectonic plates that slowly move. Much of the movement and pressure at the edges of these plates causes geohazards. Malaysia sits away from the most active plate edges, so large earthquakes are rare here, but nearby regions and heavy rain still bring risks such as tremors and landslides.
Common geohazards
- Earthquake: a sudden shaking of the ground when rocks under pressure suddenly slip along a fault. Strength is measured on the Richter scale.
- Volcano: an opening in the crust where hot magma, gas and ash escape from below. Erupted magma on the surface is called lava.
- Landslide: the sliding of soil and rock down a slope, often after heavy rain loosens the ground.
- Tsunami: huge sea waves caused by an undersea earthquake or volcanic eruption.
Key idea
Most earthquakes and volcanoes happen near the edges of tectonic plates, where the crust is under the greatest stress.
Staying safe
People cannot stop geohazards, but they can reduce the harm. Scientists monitor the ground to give warnings. Buildings can be designed to resist shaking, and drills teach people what to do. During an earthquake indoors, the advice is to drop, cover and hold on under a strong table.
Remember
- Geohazards are natural but can be dangerous.
- Earthquakes are measured on the Richter scale.
- Warnings and good planning save lives.