<p>A fault is a crack in the rock that shows movement over time. The movement may have stopped (eg. small faults seen in the field in the UK) or be essentially dead even though the crack still represents a weakness that occasionally shows a small amount of movement (e.g. the Great Glen Fault in Scotland).</p>

<p>Yes it is often possible to map a fault in 3d by plotting the hypocentres in 3d. For example, a good estimate of the fault area that slipped can be found by plotting aftershocks of a large earthquake (although beware of adjoining faults that might see shocks as their stress regime has changed).</p>

CC BY-SA 3.0
2014-06-10T00:55:19.430Z
+1 So far, this is the [best explanation of faults](http://epicentral.net/faults/) I've found, though possible there's some issue with it I'm not seeing.
blunders
CC BY-SA 3.0
2014-06-10T00:59:16.340Z
Yes that goes in to a lot more detail, even including field descriptions. If you can explain where your issue is, we can try to resolve it for you.
winwaed
CC BY-SA 3.0
2014-06-09T18:44:08.443Z
2014-06-09T18:44:08.443Z
winwaed
<p>Curious if to what degree it is possible to cluster epicentres as originating from a single formation/fault? Seems like it is possible that apart of the issue might being able to map the hypocentre of a faults slope, but what is not clear is if that is true, or if faults are really more a collections of formations that vary and at a high-level behave as one, but often independently behave when reviewed on a small scale due to the formations local attributes.</p>

<p>Which leads to my real question, what is a fault?</p>

CC BY-SA 3.0
2014-06-11T22:14:54.703Z
Are you asking about specifically seismogenic faults? (i.e. faults capable of causing a significant earthquake)
Joe Kington
CC BY-SA 3.0
2014-06-11T22:39:04.513Z
@JoeKington: Literally mean what is a fault; as noted below, in a comment to the current answer, this is the best [explanation of faults](http://epicentral.net/faults/) I've found so far; I'm open to changing the answer selected if a better answer is posted. If it's still not clear what I'm looking for, just let me know. Thanks!
blunders
<geophysics><earthquakes><tectonics>
What is a fault?
blunders
# What is a fault?

(Asked by: username_0 on 2014-06-09)

Curious if to what degree it is possible to cluster epicentres as originating from a single formation/fault? Seems like it is possible that apart of the issue might being able to map the hypocentre of a faults slope, but what is not clear is if that is true, or if faults are really more a collections of formations that vary and at a high-level behave as one, but often independently behave when reviewed on a small scale due to the formations local attributes.

Which leads to my real question, what is a fault?

**Tags:** geophysics, earthquakes, tectonics

> **Comments:**
> **username_1**: Are you asking about specifically seismogenic faults? (i.e. faults capable of causing a significant earthquake)  
> **username_0**: @username_1: Literally mean what is a fault; as noted below, in a comment to the current answer, this is the best [explanation of faults](http://epicentral.net/faults/) I've found so far; I'm open to changing the answer selected if a better answer is posted. If it's still not clear what I'm looking for, just let me know. Thanks!  

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## 1 answers

### Answer by username_2 on 2014-06-09. Score: 7 | Accepted answer

A fault is a crack in the rock that shows movement over time. The movement may have stopped (eg. small faults seen in the field in the UK) or be essentially dead even though the crack still represents a weakness that occasionally shows a small amount of movement (e.g. the Great Glen Fault in Scotland).

Yes it is often possible to map a fault in 3d by plotting the hypocentres in 3d. For example, a good estimate of the fault area that slipped can be found by plotting aftershocks of a large earthquake (although beware of adjoining faults that might see shocks as their stress regime has changed).

> **Comments:**
> **username_0**: +1 So far, this is the [best explanation of faults](http://epicentral.net/faults/) I've found, though possible there's some issue with it I'm not seeing.  
> **username_2**: Yes that goes in to a lot more detail, even including field descriptions. If you can explain where your issue is, we can try to resolve it for you.  

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