GeoNet celebrates 15 years of monitoring shakes

Maps showing ground-shaking intensities can now be produced within a couple of minutes of an earthquake. Photo / David Alexander
Maps showing ground-shaking intensities can now be produced within a couple of minutes of an earthquake. Photo / David Alexander

Three hundred and fourteen thousand earthquakes - or 57 each day.

That's how many shakes New Zealand's geohazard monitoring system, GeoNet, has picked up in its 15 years of existence, being celebrated this week.

Before its inception in 2001, the country's monitoring network was precarious and sparse, consisting of ageing instruments that were consuming an increasing amount of money just to keep them operating.

The need for modernisation and expansion was pressing.

For instance, in 2000 seismologists had to rely on faxed records from the then Auckland Regional Council's volcano monitoring team to interpret what was thought to be an earthquake off Auckland's east coast.

At that stage, scientists had almost no ability to distinguish between an earthquake in the Hauraki Gulf and a possible reawakening of the Auckland volcanic field.

In another example, in the mid-90s it took scientists about three months to produce a map showing ground-shaking intensities throughout the South Island following a magnitude 6.5 quake at Arthur's Pass.

Such maps are now produced automatically within a couple of minutes of an earthquake.

The change came about after the Earthquake Commission entered an agreement with GNS Science to substantially upgrade and expand New Zealand's geohazard monitoring networks, which are operated by GNS Science.

EQC initially stumped up $5 million a year for 10 years to fund what has become an international leader in national hazard monitoring networks.

EQC's funding support subsequently increased to $8 million a year and currently stands at about $12 million.

With EQC on board, change came rapidly with dozens of new instruments installed in the first 12 months all sending real-time information to new data hubs at GNS Science offices in Wairakei and Lower Hutt.

GeoNet director Ken Gledhill says a 10-year contract is unusual in today's world.

"We regard EQC's commitment to a 10-year time frame as fantastic and a triumph for common sense."

"Some things take time to reveal their true value, and with damaging earthquakes and volcanic eruptions we are dealing with low frequency, high-impact events."

Of the 314,000 quakes recorded by GeoNet, the vast majority were small and not felt by humans, but 1100 were greater than magnitude 5.0

Keeping a national network of 600 monitoring instruments working flawlessly all year round is no mean feat, Gledhill said.

"Some of our equipment is in very remote places and some of it has to cope with fairly brutal weather.

"Yet when the big moment comes, everything has to work heroically without missing a beat and I'm pleased to say it does."

From the outset, the intention had been to monitor all New Zealand's main geological hazards -- earthquakes, volcanoes, landslides, and tsunamis.

And EQC stipulated that all the data collected should be freely available to everyone.

An unusual concept at the time, this far-sighted approach has turned out to be a master stroke with many organisations and individuals across New Zealand using the data in creative ways that could not have been imagined in 2001.

Another feature, unusual in an international context, is that all the main geological hazards are monitored under the one roof.

"Housing all the monitoring arms in one entity delivers operational efficiencies and offers research opportunities that are hard to achieve when disciplines are funded and organised by separate organisations, which is common overseas."

Fifteen years ago, Gledhill said, we could not have imagined there would be 600 real-time monitoring instruments throughout the country, that there would be 250,000 downloads of the GeoNet Quake App, and that there would be 16,000 hits per second on our website during widely felt earthquakes.

"As a result of the high quality data collected by the GeoNet project, science understands vastly more about the mechanisms of earthquakes, tsunamis, and volcanic eruptions than it did 20 years ago," he said.

"In parallel to these advances, we've created something really special -- a community where New Zealanders better understand natural hazards and share their experiences."

Over the next 10 years Gledhill sees more emphasis on "impact reporting" and more two-way communication with the community of GeoNet users.

At present GeoNet's focus is "event reporting" where it provides rapid information on where, when, and how big.

With impact reporting, it would provide near real-time information on the likely impacts to people and infrastructure.

This would rely on a combination of data from instruments, community reporting or citizen science, and computer modelling informed by research.

"Overall, the development of GeoNet will continue to parallel that of computer and data communications technology.

"As well as this, we expect to see a huge increase in the number and usability of monitoring sensors deployed around New Zealand."

- NZ Herald

Get the news delivered straight to your inbox

Receive the day’s news, sport and entertainment in our daily email newsletter


© Copyright 2016, NZME. Publishing Limited

Assembled by: (static) on production bpcf03 at 21 Oct 2016 10:32:49 Processing Time: 354ms