The earthquake monitoring system at Mt Ruapehu has recently recorded a sequence of small earthquakes at 3-6 km depth clustered under the volcano. Te Wai ā-moe (Ruapehu Crater Lake) is slowly heating, currently reaching 19 °C. Other volcanic monitoring indicators remain within normal ranges. Volcanic activity remains low. The Volcanic Alert Level remains at Level 1 and the Aviation Colour Code at Green.
On 27 October 2023 magma started accumulating beneath the Reykjanes-Svartsengi volcanic system in Iceland. Located just 3.5 km north of the town of Grindavík with a population of 4000 people. Grindavik is a popular tourist spot for the geothermal activity and supports the fishing industry from its port.
An exciting new feature is now available on our GeoNet app. Now when an earthquake occurs with a magnitude of 3.5 or greater, in addition to the Felt Reports, you can also get a measure of ground shaking intensity for different parts of the country.
Tsunamis are uncommon events and can be extremely deadly, but they needn’t be. Today, on World Tsunami Awareness Day we join the National Emergency Management Agency (NEMA) in urging Aotearoa New Zealand to take a few minutes to check their tsunami zone and get familiar with small actions that could make a big difference in an emergency.
The threat of tsunamis does not just apply to our coasts – lakes can also be vulnerable to tsunamis. Today we investigate what can cause lake tsunamis, where they have occurred in Aotearoa New Zealand, and how we can be prepared for them.
Welcome, haere mai to another GeoNet Data Blog. Today we are going to talk about RSAM (Real-time Seismic Amplitude Measurement), what it is, why we need it, how we calculate it, and how we use it in our day-to-day work.
Our place in the Pacific puts us at risk from many different tsunami sources, but even some of the biggest earthquakes originating in the Kermadec Trench are not able to be strongly felt in New Zealand. Offshore seismic events may generate a tsunami that can travel 800km/hr in deep waters to reach our coasts within an hour, without any obvious natural warning. We call these “stealth tsunamis”, and New Zealand’s special geological situation makes us particularly at risk from them.
After a short heating phase starting mid-July this year, Te Wai ā-moe (Ruapehu Crater Lake) has now cooled back down. Other monitoring indicators are within normal ranges for Mt Ruapehu. Volcanic activity remains low. The Volcanic Alert Level remains at Level 1 and the Aviation Colour Code at Green.
Based on gas and observation flights over the last few months, we conclude activity at Whakaari/White Island remains limited to minor steam and gas emissions. No eruptive activity was detected over the past few months, and changes in the active crater area have been minimal. The Volcanic Alert Level remains at 2.
You might have noticed in the minutes following an earthquake, the magnitude and its precise location may change. Usually these changes are slight, but for larger, more complex events like the 2016 Kaikōura earthquake, they could be more significant. We explain why this happens and take a closer look at the different types of magnitudes there are.