New Zealanders are at risk of damaging earthquakes and, with most living close to the ocean, they are threatened by tsunami.

Generally, earthquake and tsunami monitoring only describes earthquakes as point-sources, rather than three-dimensional regions and processes through time (the fourth dimension).

This simplification becomes increasingly inadequate with increasing size and complexity of earthquakes, as it prevents prompt and appropriate response when risks of tsunami and damaging aftershocks are greatest.

Science can now describe the four-dimensional earthquake source, and associated shaking and tsunami through post-processing in the days to months after the earthquake, yet not in the immediate aftermath.

Resolving this science issue by operationalisation of post-processing techniques is a necessary precondition for development of next-generation effective tsunami early warning systems and understanding the immediate and cascading impacts of strong ground shaking.