|The eruption starts from a full overflowing pool. There appears to be little if any warning prior to the eruption. Quickly boiling starts towards the middle of the pool and the pool rises. The bursting of the eruption starts slowly but builds throughout the eruption. As the bursting continues, water is washed over the high lips along the side of the pool. In 1997, when the eruption ended, the pool would drain out of sight and the two perpetual spouters that were located on the trail end of the pool would stop. One of the perpetual spouters would restart about 30 minutes after the eruption and the other would restart about 45 minutes after the eruption. It would take the pool 2-3 hours to refill and overflow.
Spiteful will occasionally erupt in a series of two eruptions. The second eruption of the series occurs about an hour after the first and starts from a low pool.