A Seismic Fibrillator Node is a potent disc-shaped T'au device that emits resonant frequencies of such power when activated that they cause localised seismic tremors. When the device is used correctly, these tremors can be greatly magnified and last for an extended period of time.
Upon the watery world of Salash'hei, Seismic Fibrillator Nodes placed on the ocean floor to awake the wrath of the world's oceanic vents caused tsunamis of such immense size that an entire Ork navy was wiped out.
Seismic Fibrillator Nodes were also used during the defence of Lub'grahl when a clutch of them where dropped into B'oghal, the Great Abyss. Before the hour was out, every one of the delicate rock spires that covered the world collapsed, burying all of the invading Ork hordes under forty metres of rock.
- Farsight Enclaves - A Codex: Tau Empire Supplement (6th Edition) (Digital Edition), pp. 169-170, 304-305, 320