Was the M6.0 earthquake at 7:14 am an aftershock of the M6.7 quake at 7:07 am?
Seismologists are divided about whether the M6.0 was an aftershock of, or an earthquake triggered by, the M6.7 earthquake that occurred on October 15, 2006. They are, however, unanimous in believing that the distinction is not an important at this time. The relation between the two quakes will become clearer with further study.
An important component of the answer lies in determining what actually caused the M6.7 event. Not much is known about earth structure that deep (39 km). The roughly northwest-southeast distribution of the aftershocks probably outlines the M6.7 rupture. An aftershock would have occurred within the structure that ruptured, and the M6.0 - the second quake - lies well to the north of that cluster.
Map shows the location of the two main earthquakes (large red squares) as well as the first 11 days of aftershocks (red circles occurred greater than 20 km depth, black and white circles occurred shallower than 20 km). The two large red circles indicate the two largest aftershocks; they occurred within the first 48 hours.
Next Question: How long will the aftershocks continue?
Updated: 31 October 2006 (pnf)