Jumpmine

Though not an official name, the Jiralhanae Land Mine can be seen on Halo 3 's multiplayer level Sandtrap.

Description
The Jiralhanae land mines is a defensive security measure designed by unknown forces, (presumably by the Covenant), to eliminate individuals that trespass beyond the map's border. When an individual trespass this border up to a certain length, these mines will automatically eject themselves from their buried position, rising vertically about two to three meters above the ground, and detonate similarly to a UNSC fragmentation grenade.

Since the mines are designed to explode above a target, they can shower the crews of vehicles like the Mongoose or Prowler, or infantry who venture into the minefield, with explosive debris. The mines are less effective against aerial targets (due to the fact that the mines can only reach and explode on a relatively short height above the ground) unless the player is flying relatively low to the ground. The mines can injure players even with invincibility turned on, when shielding inside a Bubble Shield or behind a Deployable Cover, similar to the Automated Plasma Turrets in Snowbound.

The visual design of the Brute Land Mine looks very similar to a larger version of the Jiralhanae spike grenade, though without the handle or the three spikes on the top edges.

Trivia

 * The landmine bears similarities to the WWII-era S-mine, more commonly known as the "Bouncing Betty".
 * Overloading the map will remove the landmines from the match and prevent them from spawning by the player.