Australian scientist Prof Kevin McCue says yesterday's major South Island earthquake may bring the Alpine Fault closer to failure, and also warns of a magnitude 8 quake in Wellington.
But University of Otago scientists suggest such effects are unclear, and some say such an outcome is ''speculation''.
Prof McCue is an adjunct professor at CQUniversity, and is president of the Australian Earthquake Engineering Society and director of the Australian Seismological Centre.
New Zealand's Science Media Centre quotes Prof McCue as saying this was ''yet another major New Zealand earthquake not on the Alpine Fault system or any known major mapped faults'' marking the Pacific and Australian Plate margin.
''The consequent stress loading on the Alpine Fault may be bringing it closer to failure and a magnitude 8 earthquake on the Wellington Fault must be in the minds of the New Zealand emergency management, the worst case scenario.''
It included two sub-events, one near Culverden, in North Canterbury, and the other near Ward, in Marlborough, and with different mechanisms.
He was asked whether an imminent ''Supermoon'', with the moon coming the closest to Earth for about 70 years this week, could contribute to major earthquakes.
The moon clearly did have important gravitational effects on Earth, but there was no strong ''one to one'' evidence to show lunar influence on particular earthquakes.
The amount of force arising from tectonic plate pressures was, in any case, vastly greater than that exerted by the moon, he said.
Geologist Emeritus Prof Alan Cooper said yesterday's quake was linked to the Pacific and Australian plate boundary, and also to the Alpine Fault. It was unclear if it would make it more or less likely that a bigger quake would occur in future, he said.
