A technique facilitates analysis of hydraulic fractures. A plurality of explosive pellets is constructed for delivery into fracture or fractures of a subterranean formation. Each explosive pellet comprises an explosive material combined with an initiating member working in cooperation with a friction sensitive pyrotechnic mixture. Crushing or otherwise actuating the initiating member initiates the friction sensitive pyrotechnic mixture which, in turn, ignites the explosive material to produce explosive signals. The explosive signals may be monitored to obtain data related to the fracture or fractures.