Open Access

Determination of dip direction for the 2007 Chuetsu-oki earthquake from relocation of aftershocks using arrival times determined by cross-correlation

Earth, Planets and Space200860:BF03353146

Received: 1 October 2007

Accepted: 29 April 2008

Published: 18 November 2008


Waveform correlations were used to redetermine P arrival times at 31 stations for a selected set of 321 aftershocks of the 2007 Chuetsu-oki earthquake. These data were used with several different relocation techniques, 1-D velocity structure, 3-D velocity structure using SIMULPS12, 1-D velocity structure using hypoDD, and 3-D velocity structure using tomoDD. The results from all of these methods show a consistent southeast dipping trend for the entire aftershock sequence. The same pattern is also seen for the time period before the largest aftershock. These results indicate that the mainshock fault dips to the southeast.

Key words

Aftershocks Chuetsu-oki earthquake fault plane