Science Common Sense

1547 - How can seismic waves help us understand the layered structure of the solid Earth.

Imagine you're throwing a stone into a pond, and ripples (or waves) spread out across the water. When earthquakes happen, they create special waves called seismic waves that travel through the Earth.

These waves behave differently in different materials, like water, air, and different types of rocks. By measuring how fast or slow the waves move and what kind of waves reach a seismograph (an instrument that detects seismic waves), scientists can figure out the layers inside the Earth.

There are three main types of seismic waves: 1. P-waves (Primary waves) - move quickly through solid rocks, slower through liquid, and don't pass through gases. 2. S-waves (Shear waves) - move only through solid rocks and liquids.

When seismic waves travel through different layers of the Earth at varying speeds, they help scientists understand the types of rocks and materials inside the Earth. For example, if S-waves suddenly stop, it might indicate the Earth's liquid outer core. By studying these waves, scientists can create an 'image' of the Earth's insides.