The Earth Crackles

The earth makes crackling noises too, but the cracks are so big and so long that we don't ever hear them - we feel them! Have you ever been in an earthquake? Each earthquake is just a single "crack" in the crackling of the earth!

Here is the sound of one earthquake, the Northridge Earthquake, sped up by a factor of 100. This earthquake happened near Los Angeles, in California, in 1994. During this earthquake, the whole valley probably jumped about an inch (a couple of centimeters). Only an inch you say? That was enough to knock down bridges!

How do we know the earth crackles? We took an entire YEAR of earthquakes, and speed them up a whole lot. Each crackle is an earthquake: the early ones happened in January, and the last ones happened in December. Doesn't it sound like the crackling of fire, or rice krispies?