Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

Table 1

Crustal velocity structure in the Tianshui area.

Layer	Thickness^1 (km)	𝑉𝑃^1 (km/s)	𝑄𝑃^2	𝑉𝑆^1 (km/s)	𝑄𝑆^2	Density^3 (g/cm^3)
1	0.25	3.9	123	1.4	36.9	2.58
2	12.5	5.95	389	3.5	194.5	2.76
3	11	6.2	510	3.6	255	2.84
4	11	6.4	480	3.7	240	2.84
5	7.5	6.5	550	3.75	275	2.97
6	13	6.75	550	3.88	275	2.97
7	90^4	8	550	4.55	275	3.40

¹𝑉_𝑃—layer’s P-wave velocity, 𝑉_𝑆—layer’s S-wave velocity.
²𝑄_𝑃—layer’s P-wave quality factor, 𝑄_𝑆—layer’s S-wave quality factor.
³Density—layer’s density.
⁴Mantle (half-space).