Twelve seismic sensors have been installed in buildings across Hawke's Bay, including the Flaxmere community centre, as part of a one-year Sentinel trial. Photo / Paul Taylor
Twelve seismic sensors have been installed in buildings across Hawke's Bay, including the Flaxmere community centre, as part of a one-year Sentinel trial. Photo / Paul Taylor
Twelve seismic sensors have been installed in buildings across Hawke's Bay to help offer early warnings and insight into how the structures fare in earthquakes.
The one-year seismic sensor network trial, named Sentinel, is a partnership between Hawke's Bay Civil Defence Emergency Management (HBCDEM) and Canterbury Seismic Instruments (CSI).
InJuly, Sentinel sensors were installed at key buildings across the region to measure the actual earthquake shaking and ground movement at the building.
This then provides a status notification to advise staff if they should evacuate immediately, inspect for hazards, or carry on business as usual.
Buildings include HBCDEM Group Emergency Coordination Centre, the Central Hawke's Bay Emergency Operations Centre, the alternate Emergency Operations Centre at Wairoa Hospital, and other important lifeline and community sites like the Hawke's Bay Airport, and Flaxmere Community Centre, along with two existing Fire and Emergency New Zealand sites.
Group controller Ian Macdonald said having a "direct, building-specific measurement" provided in real-time would enable "fast, evidence-based decision" making about which buildings have experienced shaking beyond their design tolerance and whether a response is required to assess the wider area.
"Having instant alerts and clear, reliable information in real-time on the status of a building will help emergency management teams make the right calls, quickly.
"We can't prevent earthquakes, but we can be ready for them.
"We can harness the right tools to manage their impacts and respond appropriately to keep people safe and help ensure business continuity."
Group controller Ian Macdonald says the "direct, building-specific measurement" provided in real time by the Sentinel sensors will enable "fast, evidence-based decision" making. Photo / Paul Taylor
Macdonald said the trial sensor network had already provided some useful insights, pointing to analysis of the widely felt moderate magnitude 4.9 earthquake near Waipukurau earlier this month.
The trial network analysis found during the quake:
• The strongest shaking is not necessarily nearer the event epicentre. • Close buildings on different soils have different experiences. • The earthquake had a lesser impact on buildings with a greater Importance Level (IL) and tolerance to earthquakes.
"What we saw from analysis of the September 4 event is the importance of location, local soil variation and building classification," Macdonald said.
How it works?
When an earthquake hits, the Sentinel network immediately collects all the shaking data.
A range of ground shaking "heat maps" are then created from the sensor data, which show shaking intensity reported as Modified Mercalli Index (MMI).
These data aid decisions about probable damage to underground services such as power, water, and telecommunications. This information can be sent to different user groups within two minutes of an earthquake.
Sentinel has hundreds of installations spanning New Zealand and is provided to a number of users ranging from councils, hospitals, fire stations and airports, along with many businesses.
The first sensors were installed in Christchurch, and sensors now operate in several cities including Wellington.
