摘要 |
<p>An improved seismic energy source having a base with an opening therethrough and having a gun mounted on the base for firing a projectile to impact on the earth's surface and generate a seismic signal, the improvement including a spatter plate and a flexible diaphragm affixed at its periphery to the base lower end, the diaphragm having an opening through which the projectile fired by the gun passes, the diaphragm serving to keep the base chamber free of compacted soil kicked up when the projectile impacts the earth and to contain and quiet the muz-zle blast.</p> |