Volcanoes are geological structures that are formed as a result of the Earth’s need to find an escape route for the energy contained in its center. It doesn’t matter if it is on dry land or on the ocean floor, volcanoes can appear in any region where tectonic plates meet. When they are born on the seabed they are called underwater volcanoes and they can form entire islands.
The center of the Earth is made up of molten metals that keep the planet functioning, as they generate the magnetic field that protects us from the threats of space. But in itself, the geoid we call home is more complex than just a hot center. It is made up of different layers that the further outward, the more solid they become, but all the energy contained in the center and the layers closest to it, look for a way to escape in some way.
This is how volcanoes are formed, which are fissures in the Earth’s surface through which material from the depths escapes, whether in the form of gas, lava or ash. The most interesting thing is that these cracks can occur even if it is the bottom of the sea, what we call . After all, dry land exists there too, except it’s covered by tons of marine.
What are underwater volcanoes?
In the layer of the Earth known as the lithosphere, there are what we know as tectonic plates. These are the most hardened parts of the Earth’s sediment that are fragmented and often see volcanoes born right on their edges. And although we usually associate the ocean floor with a fairly pronounced depth, the truth is that dry land can also be found there, except that it is covered by large volumes of water.
When a temperature rise occurs in the magma in the innermost layers of the earth, the pressure contained within will rise and seek an escape route. In that sense, it is not strange that even on the ocean floor you can see the birth of imposing volcanoes, which are called submarines, which are nothing more than fissures caused by the pressure generated by the incandescent material at the center of the Earth.
The vast majority of them are found, as we have already said, on the edges of the tectonic plates that, in the case of the deep sea, are called oceanic ridges.
Are underwater volcanic eruptions possible?
Like a terrestrial one, underwater volcanoes can erupt, spewing magma, gases and vapors in the process. Although it could be taken as the greatest contradiction in nature, the truth is that in a submarine, fire and water are in the same situation. Sometimes when it is close to the water surface, underwater eruptions can be detected thanks to the appearance of fumaroles or hydrothermal vents.
Not all underwater volcanoes are the same and therefore, their eruptions are not the same. They will intrinsically depend on the depth at which they are located, since the pressure usually varies and will influence their behavior. But it is known that underwater eruptions can be of at least two types: sporadic or continuous. In the first case, the activity occurs isolated in time, contrary to the continuous ones that constantly throw incandescent material into the ocean.
Continuous underwater eruptions are very important, since the volcanic material ends up rising to the ocean surface. And later it is responsible for forming new islands, such as , which is located just above the Atlantic ridge.
How many underwater volcanoes are there?
Due to the nature of this type of volcanoes, researchers have only had the necessary tools to study them for a short time. But it is estimated that it is not a strange phenomenon, so the deep sea is home to at least a million of them. However, researchers estimate that there are currently around 5,000 active underwater volcanoes around the globe.
The most important are Morro Rock in California, Molokini volcano in Hawaii, Oceania, Kolumbo in Greece and Marsili in Italy. And the Hunga Tonga, located in Oceania.