The discovery of pink pumice in the gigantic pumice raft of the 2012 Havre, which traveled across the southwest Pacific Ocean, has prompted academics to acknowledge the enormous potential of underwater volcanic eruptions.
Professor Scott Bryan, Dr Michael Jones, and PhD candidate Joseph Knafelc were interested by the appearance of pink pumice inside the huge pumice raft that occurred from the Havre 2012 deep-sea eruption in a study published in the Nature portfolio journal Communications Earth and Environment.
The new study comes after the recent catastrophic eruption of the Hunga Tonga Hunga Ha’apai volcano in Tonga, some 1200 kilometers north of the Havre volcano, which has drawn global attention to the explosive potential and risks of underwater volcanoes.
Professor Bryan, who has spent more than 20 years researching pumice rafts, said the pink pumice created in the 2012 Havre eruption gave new information about how magma may fly out and up from underwater volcanoes.
“Compared to Hunga Tonga-Hunga Ha’apai, Havre is far more isolated. Its top is 900 meters below sea level, and the closest inhabited regions on New Zealand’s North Island are around 800 kilometers distant “Professor Bryan said the following.
When the volcano erupted in 2012, no one was there to see it. The color of the pumice, on the other hand, conveys the tale of what transpired.
The novel model presented in the study, according to Joseph Knafelc, the study’s principal author, “challenges the established depth limitations for explosive eruptions.”
Mr Knafelc said, “The prevalent belief is that underwater volcanoes, especially in deep water like Havre, cannot be explosive and instead produce lava flows on the seabed.”
“However, few subsurface eruptions have been documented, and previous research had overlooked the presence of pink pumice in the pumice raft.
“The pink to red color in this example is important because it indicates that the pumice had to be ejected into the air at temperatures exceeding 700 °C for microscopic iron particles to oxidize and produce the reddening.
“The issue is that it was an undersea eruption that had to make its way up through almost a kilometer of water. The only way it could accomplish this is if the eruption was very strong, punching through the ocean water and forming an eruption column in the atmosphere.”
The study explains how the eruption’s core was a strong jet that was insulated from the surrounding ocean.
Professor Bryan said, “The pink pumice and its thermal history show that the core of the eruption column remained unaffected by the cooling impacts of the ocean water.”
“In as little as a few seconds, an explosive eruption column might send heated pumice into the sky.
“This was a massive eruptive event. The difficulty is that past research ignored or minimized the explosive potential of undersea eruptions, even in extremely deep water, and hence the dangers they bring.
“As a timely reminder, we just experienced in Tonga the force of explosive underwater eruptions, as well as their destruction and influence, the consequences of which could be observed throughout the globe.”
Professor Andrew Berry and Dr Guil Mallman of the Australian National University, Professor David Gust and Dr Henrietta Cathey of QUT, Dr Eric Ferré of the University of Louisiana in Lafayette, and Daryl Howard of the Australian Synchrotron were part of the study team. Researchers from QUT’s Earth and Atmospheric School and the Central Analytical Research Facility contributed to the study (CARF).
