Table | Name | Field Alias | Data Type | Description |
Primary Table | DATED | | Date | Date the earthquake occurred. The date of the first listed earthquake is 31 March 1840.
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Primary Table | TIME | | Character | Estimated time of the event origin. Based on 24-hour clock Universal time. Stored as an integer e.g. 08:15 AM is recorded as 815, 12:20 AM is recorded as 20, 23:30 PM is recorded at 2330 etc. |
Primary Table | SECONDS | | Number | Seconds component of the estimated time of the event origin. If SECONDS is negative it indicates that the event occurred in preceding minute. |
Primary Table | LONGITUDE | | Number | Longitude of the event epicentre. |
Primary Table | LATITUDE | | Number | Latitude of the event epicentre. |
Primary Table | DEPTH | | Number | Estimated depth (in kilometres below the earth's surface) of the focus of the event epicentre. |
Primary Table | PLACE | | Character | Reference to the nearest significant locality (town, district, mountain etc). It is used to assist the general public to identify the approximate location of the event epicentre within SA. |
Primary Table | MAGNITUDE | | Number | Calculated magnitude of the event based on the Richter scale or equivalent. |
Primary Table | INTENSITY | | short integer | Maximum reported intensity based on the modified Mercalli scale. |
Primary Table | ACCURACY | | Character | Code representing the accuracy of the location (X, Y and depth). Codes A-F also denote that these events were recorded by instruments. Codes I-K denote historical records.
A = within 2 km in any dimension using a local model
B = within 2 km in any dimension using a regional model
C = within 4 km in X and Y or 5 km in depth
D = within 10 km in X and Y
E = within 50 km
F = earthquake did occur but accuracy is considered poor or unknown
I = located from a good isoseismal map
K = located from a poor isoseismal map
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Primary Table | ARRIVALS | | Number | The number of instrument wave arrivals used to calculate the event epicentre location. |
Primary Table | RESIDUAL | | Long Integer | Standard deviation of the difference between the calculated and measured arrival times. This gives a partial indication of location accuracy. |
Primary Table | STATIONS | | Number | Number of individual stations used to calculate the event epicentre location. |
Primary Table | AGE | | Number | Number of elapsed months since the date of the event. |
Primary Table | SYMSIZE | | Number | Recommended size (in centimetres) for a map symbol that portrays the relative magnitude of the event that is suitable for output at scales of between 1:1 million and 1:2 million. |