<p>Z depends upon convention, but in geophysics we typically use Z=positive downward. R is radial and the positive direction is defined in the direction FROM the source TOWARD the receiver. T polarity can be determined from the right-hand rule once you have Z and R. </p>

<p>For reference, this is the based on the convention for polarity as described by Aki and Richards (1980). </p>

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2015-11-02T21:39:56.883Z
2015-11-04T17:55:24.697Z
2015-11-04T17:55:24.697Z
txpaulm
<p>I'm confused about the direction of Z (upward or downward?), R (outward or toward the source?) and T.</p>

<geophysics><seismology><seismic>
How are the ZNE, ZRT and LQT coordinate systems defined?
wsdzbm
# How are the ZNE, ZRT and LQT coordinate systems defined?

(Asked by: username_0 on 2015-06-19)

I'm confused about the direction of Z (upward or downward?), R (outward or toward the source?) and T.

**Tags:** geophysics, seismology, seismic


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## 1 answers

### Answer by username_1 on 2015-11-02. Score: 1

Z depends upon convention, but in geophysics we typically use Z=positive downward. R is radial and the positive direction is defined in the direction FROM the source TOWARD the receiver. T polarity can be determined from the right-hand rule once you have Z and R.

For reference, this is the based on the convention for polarity as described by Aki and Richards (1980).


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