A study of sediment layers in the Southern Alps has offered new insights into the likelihood of the Alpine Fault generating a large earthquake in our lifetimes, making headlines here and overseas.
The research, published today in the leading journal Science, presents a revised timeline of earthquakes occurring on the alpine faultline dating back 8,000 years. The researchers found that the 24 earthquakes occurred that occurred during this period did so with unusual regularity (in seismological terms). The average interval between quakes was about 330 years, with the shortest about 100 years, the longest interval was approximately 500 years.
The last rupture was 295 years ago.
The consistency of the fault rupturing lead the researchers from GNS Science to estimate that, based on previous patterns, there was a 30% chance of the fault rupturing in the next 50 years.
You can read more about the study on the GNS website, and read expert responses collected by the SMC here. A breakdown of the risk statistics by Prof Thomas Lumley (University of Auckland) can be found on the Statschat blog.
The research outlining the hazard profile of an ultimately inevitable fault rupture has understandably captured the attention of the media both locally and internationally. New Zealand examples include:
Campbell Live: Alpine Fault considered ticking time-bomb
Timaru Herald: Alpine quake around corner
MSN News NZ: Fault ‘well-behaved’ but big quake closer
NZ Herald News: 30 per cent chance of ‘big one’ in Alpine Fault
TVNZ News: Major earthquake in near future ‘not a surprise’ – GNS
Stuff.co.nz (and other Fairfax papers): Big Alpine Fault quake may be ‘in near future’
Greymouth Star: 30% chance of 8 quake
Radio New Zealand: Regular ruptures on Alpine Fault aid projections
Overseas coverage included:
Our Amazing Planet: New Zealand’s South Island Due for Earthquake
MSNBC: New Zealand told to hunker down for big quake
PhysOrg: 8000-year quake record improves understanding of Alpine Fault
Xinhua News: Scientists warn of major quake probability for New Zealand’s South Island