Details of how these scales compare are discussed by Rick Aster on page 8 and 9 of the Two large earthquakes, one a magnitude 9.0 and one a magnitude 8.2, occurred on Dec. 26, 2004 and March 28, 2005, respectively, along the same fault zone off the coast of Sumatra, Indonesia.The list of really large earthquakes in the previous paragraph brings up another interesting point. (Public domain. The digital information is then sent via digital data link to the central site where it is able to be used immediately by the computers processing and storing the data.Using digital stations instead of analog stations provides several important benefits:The Force Balance Accelerometer measure the acceleration of the ground as it is shaking during an earthquake. Abridged from Earthquake Information Bulletin.
Think of a seismograph as a kind of sensitive pendulum that records the shaking of the Earth. It photographically records the horizontal motion. The spring-suspended mass lags behind the motion caused by the earthquake, making the pen record the waves on the drum. )This electronic seismometer is a state-of-the art instrument. It is a measure of the largest seismic wave recorded on a particular kind of seismograph located 100 kilometers (about 62 miles) from the epicenter of the earthquake. A seismograph is an instrument designed to measure earthquake intensity and seismic vibrations during an earthquake. That's why seismologists spend so many years in college!A wave one millimeter (1000 microns) high on a seismogram would have a magnitude of 3 because 1000 is ten raised to the third power.
The data is stored electronically, easy to access and manipulate, and much more accurate and detailed than the analog recordings. They mark the points on the record at which these waves first arrive at the station.The simplest method of locating an earthquake on a globe is to find the time interval between the P- and S-wave arrivals at several seismograph stations. (Public domain. focus (hypocenter): the point of origin of an earthquake. The Richter scale is open-ended, meaning there is no limit to how small or large an earthquake might be. In concept, a seismograph has a weight which is suspended from a support that is attached to bedrock. For reasons that we won't go into, a factor of 10 change in the wave height corresponds to a factor of 32 change in the amount of energy released during the earthquake. Remember, you have to be using a particular kind of seismograph located 100 km from the epicenter when you make the measurement; otherwise, all sorts of complicated calculations have to be made. How does a seismograph measure an earthquake?
Using these tools, they can determine both the magnitude of the vibration — … (Public domain.