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

Code: HLG
Latitude:  54.18470
Longitude:    7.88386
Elevation:    41.0
Depth: 
Name: Helgoland
Region: Schleswig-Holstein,Germany
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.
 

Station comments:
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Checked against station bulletin
Heligoland
1903-19360610
1938-194309
reopened 19600106
several locations

Data at the ISC for 35 years between 1939 and 2024.