In this lesson, you will learn what seismic waves are, the various types of seismic waves, and their frequencies.
You will learn about P-waves, S-waves, Rayleigh waves and Love waves. A short quiz will follow.
Earthquakes are scary, right? Well, they’re scary because they create seismic waves, and those seismic waves carry energy. Technically all waves carry energy, but seismic waves carry a lot of it. And that is enough to send people diving for the nearest sturdy table or door-frame.
Seismic waves are low-frequency waves that travel through the Earth. They’re generally caused by an earthquake, explosion or volcano. Seismic waves are studied by seismologists and detected using seismometers. These waves are described using a number on the Richter scale.
The largest earthquake ever detected was in 1960, in Chile, and was given a rating of 9.5 on the Richter scale.Because of their high energy, earthquake waves are definitely the most damaging and dramatic. But why is it that they have so much energy?Earthquakes happen when sections of the Earth’s crust hit each other. The Earth’s surface is split into many sections called tectonic plates that float on the sea of magma underneath.
For example, most of the Pacific Ocean makes up the Pacific Plate. When these tectonic plates hit each other, or scrape alongside each other, the result is an earthquake. Because of the huge size of the plates, and the significance of the collisions, there is a lot of energy released when this happens. And that energy can cause huge amounts of damage.
Most people don’t notice the changes that happen during an earthquake from start to finish. To be fair, that’s probably not surprising considering they spend most of that time running around in a panic or hiding underneath the kitchen table. But earthquakes contain at least four distinct types of seismic waves, which are grouped into two categories of surface and body waves. An earthquake is like a four-course meal, with every course different than the last… and every course increasingly bad for you!