in november 2003, after the separation from b-15j, b-15a drifted away from ross island on the open waters of the ross sea. in december 2003, a small knife-shaped iceberg, (about 300 km²), detached itself from the main body of b-15a and started drifting northward. by january 2005, prevailing currents caused b-15a to drift toward the drygalski ice tongue, a long extension of the land-based david glacier, which flows through the coastal mountains of victoria land. a few kilometres from the ice tongue, the iceberg became stranded on a shallow seamount before resuming its northward course. on 10 april 2005, b-15a collided with the ice tongue, breaking off the tip of the ice tongue; the iceberg seemed unaffected by the collision.