The response of rock mass to stress depends not only on its physical properties but also on the effect of the other contributors in the medium. One of the main factors, especially at the crustal-scale, is the presence of fluid. In such cases, the rupture of rock mass may deviate from the well-known double couple (DC) model for earthquakes. The non-double couple (NDC) component of earthquakes can help to determine the possible presence of fluid. This is well observed in the correlation of the hydrocarbon fields in Uzbekistan with the clusters of NDC earthquakes. There, the smaller earthquakes show strong NDC component.