| Seismogram Gallery |
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| global (teleseismic) events | local and regional events | noise and other signals |
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Time: 2000/01/01 - 11:22:55.9 Location: Temiskaming, QUE Magnitude: 5.2 |
Description: Broadband recording. First visible motion is P waves. The large amplitude signal in the middle is the surface waves. These de out over a period of roughly one minute. This is distinguishable from various types of noise because of the smaller P wave signal which "grows" into the large surface waves. |
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Time: 2000/01/17 - 08:16:19.5 Location: Rumford, ME Magnitude: 3.4 |
Description: Short period filtered. This event was not visible on the broadband recording. A short period filter helped bring out the high frequency content of this local earthquake. |
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Time: 2000/01/27 - 14:49:39.1 Location: Derry, NH Magnitude: 2.9 |
Description: Short period filtered. This is a very small event to be observed a couple hundred km away. It may be tempting to write this off as "noise". Note however the first impulsive peak of the P wave followed later by the wider and larger surface wave. There is considerably more signal here than is visible on the very compressed scale of WebSeis. Using the ZOOM feature and applying a short period filter would help bring out the details of this seismogram. |
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Time: 2000/04/20 08:46:55 Location: Newcomb, NY Magnitude: 3.7 |
Description: Broad band recording. This is a classic nearby earthquake. The sharp narrow peak of the P wave and the wide larger peak of the surface wave are clearly distingushable. Like most nearby earthquakes, this one would benefit greatly from using the ZOOM feature and applying a short period filter. This would help bring out the detail. |
| Resources | WebSeis | LCSN | http://geophysics.nmsu.edu/west/WS4instructors/gallery2.html |