GeoNet (New Zealand)

GeoNet

Formation	2001 (2001)
Founder	GNS Science Earthquake Commission Land Information New Zealand
Website	geonet.org.nz

GeoNet is a New Zealand natural hazards monitoring system that monitors earthquakes, large landslides, volcanoes, tsunami, and movement of land. Earthquakes and other natural hazards are automatically listed on the GeoNet website and app, and app users are given notifications to be warned about natural hazards. GeoNet was founded in 2001 by GNS Science, the Earthquake Commission and Land Information New Zealand.

Monitoring

GeoNet monitors earthquakes, large landslides, volcanoes, tsunami, and movement of land. This monitoring is done using over 1,000 instruments across the country, with data being transmitted from its sensors to GNS Science's computers in Wellington and Wairākei. On average, the monitoring system detects over 20,000 earthquakes per year. Detected earthquakes that pass a certain threshold are automatically listed on the GeoNet website. GeoNet also forecasts earthquake aftershocks for major earthquakes, such as the 2016 Kaikōura earthquake.

The GeoNet app sends notifications about natural hazards to its users. An example of this is the 2016 Kaikōura earthquake, where the app had sent a total of over 109 million notifications within two days. GeoNet also posts about natural hazards on their social media pages, which are followed by over 200,000 people.

History

GeoNet was founded in 2001 by GNS Science, the Earthquake Commission and Land Information New Zealand. GeoNet was "relatively [obscure]" until the 2010 and 2011 Christchurch earthquakes occurred, when people started paying attention to the monitoring system.

In December 2016 GeoNet got a funding boost of up to $3 million to improve its monitoring of and responses to natural hazards. This followed criticism of the response to the 2016 Kaikōura earthquake, especially the time it took for a tsunami alert to be issued.

In January 2019 an earthquake occurred in the Kermadec Islands and another near occurred a few minutes later in Whanganui. Because it takes a few minutes for the wave forms to travel to the mainland, the monitoring system detected the two earthquakes at the same time, and was tricked into thinking that a magnitude 6 earthquake had occurred in the East Coast. A similar error occurred in 2012.

Felt reports

The GeoNet website allows people to submit felt reports and to describe the intensity of the shaking. (People can also submit a "detailed" felt report which consists of 40 questions). After the report is submitted, a coloured square is placed on a map, at the user's location. Most people make correct submissions, although some people purposefully make false reports or make mistakes, such as a VPN causing the website to not retrieve the user's location correctly. Aucklanders have a reputation for describing small earthquakes, including ones that cannot be felt in Auckland, as having "strong" or "extreme" shaking. Sometimes people try to draw images on the map using the coloured squares, such as a phallus.

In 2023, GeoNet introduced a "shaking layers" map. Rather than showing squares at the locations of felt reports, it shows the median shaking at a given location. This includes locations where no one has submitted a felt report, and avoids showing possible false reports.

Shortly after a large earthquake, Civil Defence may use the felt reports to gather information, such as power and communications outages, before the agency can gather information from other sources. An example of this is after the 2016 Kaikōura earthquake, where there was a lack of felt reports in Kaikōura, which suggested that there were outages there.

Earthquakes are not the only felt reports that the website receives. It also receives reports of tsunami, with over 17,000 reports by 2020.

The earthquake with the most felt reports on GeoNet had a magnitude of 6.0 and was located north-west of Paraparaumu, which gathered 60,688 felt reports in 2023.