What is a seismometer?
A seismometer, also known as a seismograph, is a device for recording ground motion during an earthquake. Specifically, they record ground acceleration, or how quickly the ground is changing its rate of motion. Seismometer come in many varieties depending on their purose. Some are designed to only detect small earthquakes locally. Others to detect larger quakes from a distance. More recently, a type of seimometer called a strong motion sensor has been developed to measure the extreme ground motions near the center of a large earthquake. This is useful for making a quick automated assessment of where the most damage may have occured and where rescue efforts should begin to be concentrated. For information on specific types of seismometers see Seismometers in Section II – The Details.
