In 2015 a new island appeared and became part of the Tonga archipelago which is a very rare phenomenon. Since the island developed it has become a playground for many scientists and a first expedition has recently been carried out there.
The formation of a new island
This new island appeared between the island of Hunga Tonga and Hunga Na’apai (Tonga) between December 2014 and January 2015 following a volcanic eruption. In 2017, NASA commented about this discovery in a statement accompanied by a video that you can find at the bottom of this article, showing the formation and the start of erosion on the island. The American Space Agency remarked that this island was the first to appear and remain during a time when satellites exist. This island is visible from space with a summit reaching 120 m high.
However it wasn’t until 8 October 2018 that the very first expedition of this new island was carried out. This expedition was carried out by Dan Slayback from NASA’s Goddard Space Flight Center as mentioned in an article published on NASA’s blog on the 30 January 2019. The goal of this expedition was to study the flora, fauna and soil of the three year old island.
What did researchers find?
According to NASA, the new Tongan island is part of three islands that have emerged over the last 150 years and have remained. In fact this type of island generally doesn’t last long due to wave erosion which destroy it within a few months. This aspect of the island interested NASA, who wanted to know more about how the Earth’s new islands form and how they evolve. This could give them an indications of how volcanic landscapes interacted with water on Mars in the distant past. In addition, researchers made GPS measurements of the position and altitude of the new island and attempted to analyze signs of erosion.
Scientists mention a light-colored material visible on satellite images. This material is mud, or more precisely clay. It is intriguing as it descends from the small cone of the island. Obviously, it’s not ash. As for the soil, the island is covered with black pea sized gravel. The new island is connected to one of it’s neighbors by a tiny isthmus, a place where vegetation is already developing. On the cone side, many bird droppings were also observed.
A second expedition
This island could disappear like the majority of others but perhaps not before a few decades. According to Dan Slayback, the island is eroding at a significant rate, higher than predicted. It is also subjected to landslides as can be seem by the great eroded cliff which clearly did not exist when the island was first formed.
Another expedition should be organised later as researchers still have unanswered questions. These researchers would like to know what the shallow seabed around the island looks like, and what hydrothermal processes have allowed the material to solidify so that it can resist erosion for many years.