By: Sophia Tsang

A year ago today (4 May 2019 (New Zealand time)), a volcanic fissure opened in the Leilani Estates subdivision on Hawai‘i Island (USA). The dramatic footage quick spread across the world, and then like most disasters, was replaced in the news cycle. VGP PhD Candidate Sophia Tsang spent two months on Hawai’i six months after the eruption commenced to learn more.

While people in Hawai‘i reflect on how different their lives have been over the past year, I thought it would be nice to briefly describe the eruption and how it could be similar to future eruptions in Auckland. In the middle of the afternoon, a crack that had appeared in someone’s backyard suddenly began fountaining lava. The sight quickly caught a unmanned aerial system pilot’s attention (see video here), and the world soon knew a new eruption had begun in Hawai‘i. Although many local residents were caught by surprise at the timing of the eruption onset, there were precursory signs that an eruption could occur in the near future. For weeks, there had been an uptick in the number of earthquakes, and lava closer to the volcano’s primary vent had drained. The fire-fountaining fissure had opened in the highest lava hazard zones on Hawai‘i, the eastern rift zone of Kīlauea Volcano and was soon joined by over 20 more fissure friends. The ensuing three month-long eruption held and continues to hold uncertainty for the residents as questions of access and rebuilding remain. Although we generally expect Hawai‘i to be home to an eruption (indeed, it’s been a huge tourist draw for decades), other locations could experience similar events too.

Although it’s hard to imagine, Auckland could experience a very similar eruption in the future. Auckland is situated on top of a volcanic field. A volcanic field is a type of volcano that does not have a central vent, rather there are many vents spread over a large area. Thus, we will have harder time predicting the location of the next eruption, and most of the volcanic field is either underwater or under urban/suburban structures! If you are interested in what an underwater eruption in Auckland may look like and are based in Auckland, I highly recommend that you visit the Auckland Museum’s Volcano House (which has been updated in the past two years!). A similar simulation for an eruption on land has not been created (yet!), so transposing the video above onto an Auckland location in your mind is currently as close as you can get. Hawai‘i Island had a few advantages over Auckland in terms of the vulnerability factors though. First, Leilani Estates has a much lower population density than Auckland does. Thus, an Auckland eruption would likely affect many more people than the eruption in Leilani Estates did. Second, people living in Hawai’i tend to be more aware of their volcanoes and their potential for eruption. If you’d like to learn more about how Auckland could be affected by eruptions, I’d highly recommend you take a look at the Determining Volcanic Risk in Auckland (DEVORA) hypothetical scenarios developed here. Hopefully, those of you living in Auckland will never experience an event similar to the eruption in Leilani Estates (you aren’t likely to!), but just in case, it’s worth learning more about our Pacifica neighbours and their recent eruption.