We know from experience about the effects of a massive earthquake on a major city in New Zealand but what would happen if a volcano erupted?
Scientists have been looking into that scenario - particularly what might happen if there's a volcanic eruption in Auckland.
Researchers from GNS Science, and Canterbury and Massey universities, have based their study around a hypothetical 2-month-long period, beginning with the first signs of unrest, through to the end of the eruption, and the emergence of a new volcano near Mangere Bridge.
The warning of a future eruption varies from as little as a few hours, to as long as a couple of weeks.
Sarah Robson spoke to one of the authors of the research, Tom Wilson, who's an associate professor in disaster risk and resilience at the University of Canterbury.
He says we don't know exactly where the next eruption in Auckland will be but, when it happens, it's likely the magma will connect with a body of water and there will be a "very explosive initial eruption."