Nothing! This is a completely natural process - ice builds up over time in the shelf and it has to be lost somehow. The calving of the iceberg is, in itself, not a result of human activity.
If you mean more broadly how can we help prevent the loss of ice from Antarctica, then I'm not a climate policy expert, but https://350.org/ is a good place to start.
If you mean more broadly how can we help prevent the loss of ice from Antarctica, then I'm not a climate policy expert, but https://350.org/ is a good place to start.