Station details:
================

Code: GRM
Latitude: -33.31333
Longitude:   26.50831
Elevation:   610.0
Depth: 
Name: Grahamstown
Region: Cape Province,South Africa
Status: 

        
Arrival picks statistics
Travel Time Analysis
On the top graph every dot represents the median residual for one month of data. The green line is the overall median; the orange line shows the standard deviation (smad) based on the median absolute deviation (mad), whilst the red line shows twice the standard deviation (2 * smad).
The bottom graph shows the number of residuals for each month. The red columns show the number of residuals whose median (for that month) is outside two standard deviations from the overall median (2 * smad).
Red dots indicate a possible clock error.
Travel time residuals
Amplitude analysis
 On the top graph every dot represents the median value for that month of data.
The green line is the overall median; the orange line shows the standard deviation (smad) based on the median absolute deviation (mad), whilst the red line (if present) shows twice the standard deviation (2 * smad).
The bottom graph shows the number of observations for each month. Any red columns show those observations whose monthly median value is greater than twice the standard deviation (2 * smad) from the overall (running) median (shown in the top graph by red dots).

Red dots indicate a possible calibration error.
 

Station comments:
=================

Grahamstad
opened 19671103

Data at the ISC for 49 years between 1955 and 2013.

Known station history:
======================

First and Last use refers to the time period in which the coordinates were used by the ISC.

Code   Station name/Region                                           Latitude  Longitude Elevation   Depth  First use   Last use
================================================================================================================================

GRM    Grahamstown                                                  -33.31330   26.57330     610.0         25-08-1999 15-11-2006  
       Cape Province,South Africa