Abstract
We used broadband teleseismic data of Chifeng station to calculate the Receiver Functions, then obtained a velocity model with H-K stacking method in combination with CRUST2.0 and other previous work. With this velocity model and broadband records from 5 CDSN stations, we inverted focal mechanisms of Chifeng earthquake on August 16th, 2003 with the "Cut and Paste" (CAP) method. Then we confirmed focal depth and the source mechanisms by comparing synthetic body waves at teleseismic distance with broadband records of 9 IRIS stations. Our result shows that the best double couple solution of this Mw5.2 event is 315°, 64° and 19° for strike, dip and slip angles respectively, the second nodal plane solution is 216°, 74°, and 152°. The focal depth is 25 ± 2 km, suggesting that this quake occurred in the lower crust which is much deeper than most continental earthquakes. This lower crust earthquake requires that the rock should be colder than expected. We proposed generation mechanism of this deep earthquake and its implications in rock strength and thermal state.
| Translated title of the contribution | The 16 August 2003 Chifeng earthquake: Is it a lower crust earthquake? |
|---|---|
| Original language | Chinese |
| Pages (from-to) | 111-119 |
| Number of pages | 9 |
| Journal | Chinese Journal of Geophysics |
| Volume | 52 |
| Issue number | 1 |
| Publication status | Published - Jan 2009 |
| Externally published | Yes |
Keywords
- Focal depth
- Local waveform
- Lower crust earthquake
- Source mechanism
- Teleseismic waveform