Main Page | See live article | Alphabetical index Aftershocks are earthquakes on a smaller scale after the main quake. They happen because the newly moved rock have to be settled. Aftershocks are dangerous because they are usually unpredictable, can be of a large magnitude, and catch people offguard if they are salvaging items from a damaged building. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.