Fig. 11.
Ejection velocity v i (m/s) as a function of confining pressure (5, 50 MPa) at the source, calculated using Fagents and Wilson (1993). (a) Relationship between the mass ratio of gas to solid material and the initial velocity of ballistic ejecta. (b) Relationship between ratio of caprock to gas region height and initial velocity (v i ) of ballistic ejecta, assuming a large pressurized gas cavity enclosed by a solid caprock. Two extreme cases of initial conditions (solid lines for 2400 kg/m3 and 970°C, and broken lines for 2100 kg/m3 and 770°C) were examined for every confining pressure.