If you live in Aotearoa, you probably reach for GeoNet when the ground lurches or a volcano makes the news. It’s fast, clear, and built for our restless islands. This guide unpacks what geonet is, how it works behind the scenes, the tools you can use day to day, and a few smart habits to get the most from it—without panic or guesswork.

What is

GeoNet is New Zealand’s national monitoring and information service for geological hazards—earthquakes, volcanoes, landslides, and tsunami-related data. It’s operated by GNS Science and primarily funded by Toka Tū Ake EQC. The public sees geonet through its website, mobile app, maps, and open data feeds.

It delivers:

• Rapid earthquake detections and maps
• Felt reports and shaking intensity summaries
• Volcanic Alert Levels for active volcanoes
• Tsunami gauge readings and situational updates
• Photos, webcams, science notes, and educational explainers
• Open data and APIs for researchers and developers

Important distinction: GeoNet provides scientific information and automated alerts. Emergency instructions—like evacuations and tsunami warnings—come from the National Emergency Management Agency (NEMA) and your local Civil Defence group. Follow those first.

How it works

Sensors spread across the motu

GeoNet runs a nationwide network of instruments on land and offshore, including:

• Seismometers and accelerometers to detect earthquake waves and strong shaking
• Continuous GPS/GNSS stations to track ground movement millimetre by millimetre
• Volcano monitoring gear: webcams, acoustic sensors, lake temperature probes, and gas sensors where safe
• Tide gauges and access to deep-ocean tsunami sensors via partners

These stations send data to processing systems in near real time.

From raw wiggles to a quake on your phone

When an earthquake hits, algorithms pick the first arriving waves, estimate the location, depth, and magnitude, and publish an automatic solution—often within a couple of minutes. A duty seismologist reviews the event and may update details as more data arrives. It’s normal for magnitude, depth, or epicentre to change slightly as the solution improves.

Magnitude vs intensity

Magnitude describes the energy released at the source (e.g., Mw 6.2). Intensity describes what people feel and what objects experience at a place. In New Zealand, GeoNet uses the Modified Mercalli (MM) intensity scale—from gentle MM3 (felt indoors) up to extreme MM10+ (devastating). Shake maps and community “Felt It?” reports help show intensity patterns.

Volcanic monitoring in practice

GeoNet scientists track unrest at volcanoes such as Ruapehu, Tongariro, Taranaki, and Whakaari/White Island. They integrate seismicity, tremor, ground deformation, gas chemistry, thermal imagery, and visual observations. Findings are summarised through the Volcanic Alert Level (0–5). A level change is a communication of activity, not a guarantee of an eruption.

Tsunami data and roles

GeoNet’s seismic network, GNSS stations, and coastal gauges contribute to tsunami assessment. However, official tsunami warnings and evacuation guidance are issued by NEMA. If a local quake is “long or strong,” head to high ground immediately without waiting for any alert.

Types / examples

Earthquake tools you’ll actually use

• Recent quakes list: location, magnitude, depth, time, and a link to maps
• Event pages: shake maps, felt reports, station data, and aftershock sequences
• Shaking intensity maps: colour-coded MM levels across regions
• Quake search: filters for magnitude, time period, and region

Volcano status at a glance

• Volcano dashboards showing the current Volcanic Alert Level (0–5)
• Webcams and recent observations where available
• Background reports that explain what the data means in plain language

Tsunami and coastal data

• Coastal gauge plots for sea-level changes and tsunami wave arrivals
• Context updates during distant-source events to complement NEMA advisories

Real-world examples

• 2016 Kaikōura earthquake: geonet delivered rapid locations, strong-motion data, and aftershock tracking that informed engineering assessments.
• 2019 Whakaari/White Island eruption: ongoing monitoring and alert levels helped characterise unrest before and after the tragedy.
• 2021 Kermadec earthquakes: rapid solutions, tide gauge readings, and partner DART data supported nationwide tsunami warnings issued by NEMA.

Pros and cons

• Pros:
  • Fast, New Zealand–specific data and maps
  • Clear separation of magnitude (energy) and intensity (effects)
  • Open, free data and APIs for transparency and research
  • Volcano dashboards tailored to our active cones and calderas
  • Community “Felt It?” reports that sharpen intensity mapping
• Cons:
  • Initial quake details are automatic and may change on review
  • No public earthquake early warning system at this time
  • Coverage is strongest onshore; offshore events can take longer to refine
  • Not an emergency service—evacuation orders come from NEMA/Civil Defence

How to use or choose

Set up the GeoNet app for practical alerts

1. Install the official app from your device’s store.
2. Enable notifications and location permissions.
3. Choose your regions of interest (e.g., Nationwide plus your home and workplace).
4. Set magnitude thresholds for alerts (e.g., M4.0 nearby, M5.0 nationwide).
5. Turn on “Felt It?” prompts if you’re happy to submit quick reports.
6. Review Do Not Disturb settings so critical alerts can still get through at night.
7. Test your settings after the next small event and adjust if it’s too noisy or too quiet.

How to read a quake page in under a minute

• Check the time: is this new or already revised?
• Look at magnitude and depth together. A moderate but very shallow quake can feel stronger than a deeper, larger one far away.
• Scan the intensity map for your area’s colour (MM level).
• Browse felt reports to cross-check what others nearby experienced.
• Note any revision tag (automatic vs reviewed).

Choosing your channel

Different parts of geonet suit different needs. Here’s a quick comparison.

Smart habits for New Zealanders

• Use the app for immediacy; use the website for detail.
• Submit felt reports—they meaningfully improve intensity maps.
• For coastal areas, remember: if it’s long or strong, get gone. Don’t wait for a notification.
• After a widely felt event, expect aftershocks. Keep an eye on geonet insights and local Civil Defence updates.
• If you run a business, consider a simple dashboard using the open data feeds and a response plan tied to shaking thresholds.

FAQ

Is GeoNet the official source for warnings?

GeoNet is the authoritative source for geological hazard monitoring and data. Official public warnings and evacuation orders are issued by NEMA and your local Civil Defence group. Follow those first.

Why did the magnitude or location change?

Early numbers are automatic. As more stations report in, analysts refine the solution. Updates are normal and improve accuracy.

What do the MM intensity colours mean?

They represent Modified Mercalli intensity—how strongly the quake was felt at different places. Lower MM values mean light shaking; high MM values indicate damaging, severe shaking.

Does New Zealand have earthquake early warning?

No public earthquake early warning system is currently available nationwide. GeoNet focuses on rapid detection and post-event alerts.

How fast does geonet send alerts?

For many events, you’ll see an automatic solution within a couple of minutes. Very small or distant offshore quakes can take longer. Reviewed updates follow as needed.

What’s the difference between magnitude types?

GeoNet may report Mw (moment magnitude), ML (local magnitude), or other types depending on the event and available data. The app and site present the best current estimate and will update it as needed.

Can I rely on GeoNet for tsunami instructions?

Use GeoNet for scientific context and sea-level data. For life-safety instructions, rely on NEMA and local Civil Defence. If a quake is long or strong, self-evacuate to high ground immediately.

Is the data free to use?

Yes. GeoNet provides open data and public APIs for non-commercial and commercial use subject to its data licence. It’s widely used by scientists, councils, and developers.

How do “Felt It?” reports help?

They crowdsource intensity, filling in gaps between instruments. Thousands of reports can refine shaking maps and support damage assessment.

Where does geonet get volcano photos and webcam feeds?

GeoNet deploys webcams and instruments at or near many active volcanoes where safe and allowed, and combines those with satellite and field observations.

Should I change my settings after a big quake?

Yes. If alerts become too frequent with aftershocks, raise your magnitude threshold or tighten your region filters. You can always lower them later.

What if I have no mobile coverage?

You won’t receive app alerts without data service. For coastal hazards, always default to natural warnings: if it’s long or strong, get gone. Have a household plan that doesn’t rely on connectivity.

Final thoughts

GeoNet turns a complex, humming network of sensors into clear, useful guidance for everyday life in a tectonic nation. Set up the app, learn to read a quake page quickly, and know where emergency orders come from. With those basics, geonet becomes a calm, credible companion—before, during, and after the next shake.