Stead's video shows how the arch in the iceberg suddenly began to crack, and within seconds, tonnes of ice had fallen to the bay below.
Stead's voice is audible in the video, with a blood-curdling instruction to her husband: "Run, Rick, go — go!"
My husband and I were admiring the magnificent structure of the arch of this huge iceberg, when suddenly it collapsed and created a large tidal wave of chunks of ice rushing towards us!
