Figure 2From: Geochemistry of soil gas in the seismic fault zone produced by the Wenchuan Ms 8.0 earthquake, southwestern ChinaThe anomaly threshold of soil gas estimated by Quantile-quantile plots (Q-Q plot) method. (a)He, (b) H2, (c) N2/O2, (d)CO2, (e)Rn, (f)Hg.Back to article page