From Terra Nova Wiki
A Sonic mine is a weapon used by the people of Terra Nova to ward off dangerous predators. When the Tenth pilgrimage journeyed to Terra Nova an Allosaur set off one of the mines which caused it to flee. (Genesis, Part 1)
- Based on the other Sonic cannons used by Terra Nova, the mine is most likely not explosive in nature, but instead releases a burst of energy which scares off predators.