UNIDAD AICLE: Seismic waves and Earth's internal structure

3.     SEISMIC WAVES AND EARTH’S INTERNAL STRUCTURE

 1.       Watch this video:

https://www.youtube.com/watch?v=YxGgkF582rI

2.       Explain in your own language what you understood after watching the video

Class book text: “Seismic waves help us to understand the Earth’s structure”

An earthquake releases energy in the form of seismic waves.

Seismic waves are measured by instruments called seismographs and they are recorded on graphs called seismograms.

There are different types of seismic waves:

·         P and S waves. They travel inside the Earth. P waves are transmitted through all types of media, but S waves cannot travel through molten materials.

·         L waves. They travel through the Earth surface, and cause considerable damage in built-up areas.

P and S waves are transmitted at different speeds depending on the material they are travelling through. Sudden changes in speed at different depths inside the Earth indicate the areas where there is a change of material. These areas are called discontinuities. The most important discontinuities are:

·         The Mohorovicic discontinuity, which separates the crust from the mantle.

·         The Gutenberg discontinuity, which separates the mantle from the Earth’s core.

(Natural Sciences, OxfordClil)

 Check your new knowledge with these activities:

1.       Vocabulary matching:

http://www.educaplay.com/es/recursoseducativos/1681539/earth_s_structure_vocabulary.htm

2.       Label scheme

http://www.educaplay.com/es/recursoseducativos/1681613/earth_s_structure_fill_in.htm