A research team from Tohoku University has discovered a new petit-spot volcano in the oldest section of the Pacific plate. The research was published in the Deep-Sea Research Part I. The volcano which is in the western part of the Pacific is said to have erupted less than three million years ago. The study is said to be a unique window to understand the nature of the oceanic plate and the underlying asthenosphere before subduction.
What are petit-spot volcanoes?
Petit-spot volcanoes are young, small volcanoes that are a relatively new subject of discussion in volcanism. First discovered in 2001 close to Japan's trench located in the northeast of the country. Previously this region had seamounts that were close to 100 million years old.
Naoto Hirano, Assistant Professor of Tohuku University, coined the term petit-spot through the publication of his article in 2006. He has led various researches on the petit-spot volcanoes. These natural structures were discovered in the twenty-first century and is seen as a relatively new phenomenon.
Petit-spot volcanoes are created during the fissures on the base of the tectonic plates. The samples from the earlier research proved the movement of the upper mantle in the creation of these volcanoes.
The study has led to researches that gave way to the understanding of the details with regard to the asthenosphere- the uppermost mantle of the earth. This could be a pathway in the understanding of several natural disasters.
In the past few years, several teams working on volcanology and understanding these new presences have been able to discover the various changes in the ocean floor and upper mantle. These small volcanoes containing strongly alkaline magma was discovered in the depth of the ocean floor around the Pacific plate. The researchers believe that it formed during the early cretaceous period. It is seen that these volcanoes represent 8Myr of activity on the large oceanic floor.
New volcanic structure in Pacific
The newly discovered volcano was in the western part of the Pacific Ocean near Minamitorishima Island, Japan's easternmost point. This region was previously considered to have seamounts and islands formed 70-140 million years ago.
The research team initially suspected the region to have a small volcano while observing the data collected by the Japanese Coast Gaurd. But further investigation by the team using the Shnkai6500, a manned submersible, proved the presence of the volcano.