High frequency gas detonator
High frequency reaction mass and hydraulic cylinder assembly
High pressure sealing apparatus
High speed seismic gas exploder and method of operation
Horizontally polarized shear-wave vibrator seismic source
Human-portable geophysical energy source
Hydraulic slotted cylinder source
Hydraulic stabilization system to position and isolate a seismic
Hydraulic synchronizing system for coordinating movement of the
Hydraulic vibrator
Hydraulically-coupled, land seismic signal source