The move from COVID-19 Alert Level 4 to 3 sees the reappearance of Auckland’s background noise showing the city’s heartbeat is no longer resting.
The return of business and construction to the city on Tuesday April 28 has created a noticeable increase on the GeoNet seismograph network recording, GNS Science Volcanologist Brad Scott says.
“The network of sensitive seismographs designed to detect earthquakes and warn scientists about potential volcanic eruptions also measures the daily background hum of the city,” Brad says.
“Cities create their own seismic noise through the movements of traffic, construction and the general hustle and bustle of daily life.”
Brad says there was a noticeable drop in background seismic noise across the city after the move through from Level 3 to 4 last month when the city went into lockdown.
“With the move back to Alert Level 3, the background noise of the city returned.”
Auckland Emergency Management Principal Science Advisor Angela Doherty says the drop in the background hum of the city reflects what a great job Aucklander’s did at staying in their bubbles during Alert Level 4.
“It’s so interesting that the system we use to keep an eye on what’s happening deep underground, can also show us what we’re doing at the surface”, Angela says.
Auckland Mayor Phil Goff says the resumption of activity was good news for Auckland’s economy.
“It’s encouraging to see more evidence of how quickly construction and business activity was able to resume after the lockdown,” the Mayor says.
“Infrastructure construction, in particular, will play an important role in kick-starting the economy as we respond to the recession brought on by COVID-19.”
Working in the region’s Emergency Coordination Centre throughout the response, Angela says the seismograph located at Herne Bay also recorded an interesting spike in activity on the night of Tuesday 28 April.
“It doesn’t seem to relate to any earthquake event… it may well represent the takeaway run on the first night of Alert Level 3 that many Aucklanders made,” she laughs.
The seismographs near Auckland are part of the network of seismographs, GPS stations and tide gauges that measure every movement of the land and sea across the Auckland region. They form part of the national network managed by New Zealand’s geohazard monitoring program, GeoNet, funded by EQC and LINZ.
“The GeoNet monitoring network includes over 900 instruments across the country that are scrutinized 24/7 by our national Geohazards Monitoring Centre. Occasionally… we capture more than just natural events”, Brad says.
The latest COVID-19 help, advice and updates from Government are available at Covid19.govt.nz
