Alpine Fault rumblings

HOKITIKA: Seismologists are keeping a close eye on a ‘‘swarm’’ of quakes that have been recorded around the South Island’s Alpine Fault.

But they say there is no immediate cause for alarm regarding a big shake along the fault, which poses one of New Zealand’s biggest geological hazards.

More than a dozen quakes have been recorded around the boundary — running along the spine of the South Island — since Tuesday, including four quakes that measured 4.4, 4.7, 3.8 and 3.1.

Activity now appeared to be tailing off, but the swarm served as a good reminder to people to be prepared, Dr Natalie Balfour, of GNS Science, said.

‘‘Any time there’s activity near a large fault like the Alpine Fault, it always grabs our attention and we keep our eye on things.’’

Such clusters had been observed in the area in the past — the last swarm there was recorded after the 2016 Kaikoura Earthquake — but the events remained ‘‘a bit unusual’’.

‘‘We do get clusters of activity throughout New Zealand kind of like this — and it just means we need to pay a bit more attention to it.’’

Scientists expect the Alpine Fault is likely to cause a major quake within this generation’s lifetime.

It last ruptured in 1717 and has a 28% probability of rupturing in the next 50 years — a rate high by global standards. — NZME