In the second half of 2004

In the second half of 2004, according to the USGS/NEIC on-line database there were two earthquakes with magnitudes 7.5 or more. These are –

Date and Time

Lat

Lon

Depth

Magnitudes (mb, MS)

Prediction

2004/12/23 14:59

-50.145

160.365

10

6.6

7.5

Outside test areas

2004/12/26 0:58

3.316

95.854

30

6.3

8.8

Outside magnitude range

The first one, i.e., the 23 December 2004, M8.1 Macquarie Great earthquake, happened outside the areas of the standard M8 application (i.e., the 262 circles of 667-km radius each). The second one, i.e., the 26 December 2004, Mw9.0 (Ms8.8) off the west coast of Northern Sumatra (Great Asian) mega-thrust earthquake, requires special comments and considerations: