The underwater world hides one of the most fascinating and least known geological forces on the planet: the underwater volcanoes. Although when we think of volcanoes the first thing that comes to mind is smoking mountains spewing lava, the reality is that Most of the Earth's volcanic activity occurs underwater, far from our sight, but no less important. To learn more about these phenomena, you can visit our section on underwater volcanoes.
These hidden giants are responsible for major geological, chemical, and biological transformations on our planet. From the creation of ocean floor to the birth of new islandsUnderwater volcanoes play a vital role in the evolution of the Earth and in maintaining ecological balance.
How are underwater volcanoes formed?
Submarine volcanoes are born in areas of the seabed where the earth's crust has weaknesses, such as fractures, fissures, or tectonic plate boundaries. In these regions, magma from the Earth's mantle can rise and escape to the surface. This process can occur in three main situations:
- Zones of divergence: where tectonic plates move apart, such as at mid-ocean ridges.
- Subduction zones: where one plate slides under another, melting and generating magma.
- Hot spots: areas within plates where magma rises persistently, such as in Hawaii. They can also be investigated the Canary Islands volcanoes as an example of these.
Once magma comes into contact with water, cools quickly, solidifying and forming new mountain structures. Over time, these formations can grow large enough to emerge to the surface and give rise to volcanic islands.
Explosive activities and surprising structures
One of the peculiarities of submarine eruptions is the impact of the temperature difference between lava and waterWhen hot lava meets cold ocean water, it can cause explosions, release gases, and fragmentation of magma into multiple sizes, from fine particles to giant blocks. Understanding how these transformations occur is critical, similar to what is explained in our section on Tsunami.
A spectacular example is the volcano Havre, located in the Pacific Ocean near New Zealand. In 2012, he starred in the largest oceanic eruption ever recorded, with a gigantic floating pumice pond measuring 400 km² detected by satellite. This eruption spewed lava, ash, and colossal blocks of rock from multiple vents, surprising even the most experienced researchers.
Another case is the West Mata, also in the Pacific, whose eruption in 2009 was recorded by scientists at a depth of 1.200 meters, showing bubbling and incandescent flows in high definition, something that changed the way we study these volcanoes.
Impact on the marine ecosystem
Far from being deserted and hostile areas, submarine volcanoes are the core of unique ecosystems formed around hydrothermal vents. These vents expel extremely hot water, laden with minerals and chemical compounds, creating ideal conditions for life forms unknown outside of these environments. If you'd like to delve deeper into the differences between volcanic islands, visit our guide on volcanic islands and island arcs.
Amazing organisms have been found in these habitats, such as:
- Giant tubeworms adapted to living without light or oxygen.
- Shellfish capable of withstanding extreme pressures and temperatures.
- Chemosynthetic microbes that obtain energy from substances such as sulfur or methane.
This type of life does not depend on the sun to survive, but on a process called chemosynthesis, which has led some scientists to consider these areas as a possible early cradle of terrestrial life, and even a clue to search for extraterrestrial life on planets with oceans under ice like Europa, Jupiter's moon.
Changes in the climate and ocean
In addition to their role in biodiversity, submarine volcanoes intervene in global processes such as the carbon cycleThey release large amounts of carbon dioxide (CO2) and other greenhouse gases. To learn more about how marine life is adapting to these changes, you can consult our information on active volcanos.
This CO2 is partly absorbed by marine organisms such as phytoplankton, helping to maintain climate balance. However, an excess can contribute to ocean acidification, affecting sensitive species and weakening the marine food chain.
Underwater eruptions can also modify the ocean currents by altering the water temperature locally. An example of this was documented in 2012, when a volcano in the Pacific raised ocean temperatures, affecting the migration of species in that region.
Navigation hazards and tsunamis
Underwater eruptions are not only impressive geological phenomena, they are also may pose significant risks for vessels and coastal communities. Hazards include:
- Emission of toxic gases that can reach the surface.
- Natural obstacles such as new islands or lava domes that alter maritime routes.
- Tsunami formation due to the violent displacement of water by explosions or landslides.
For example, structures called "lava domes" can form unstable barriers under the sea that, when they collapse, generate large waves. Also to be considered is the ash and pumice generated, which can clog boat engines. To better understand how these phenomena occur, you can read more about how a tsunami originates.
Underwater volcanoes and the history of the planet
Not only in the present, underwater volcanoes have played a crucial role in historical events. About 93 million years ago, volcanic activity in the ocean caused a drastic change in marine chemistry, generating a mass extinction of marine speciesThis event left deposits such as black shale, a source of unconventional hydrocarbons.
Another example is the Great Death The Permian, which occurred 252 million years ago, wiped out more than 90% of marine species. It is suspected to have been caused, in part, by massive underwater eruptions in the Siberian Traps region, which released enormous amounts of methane and CO2.
Scientific interest and economic potential
Today, interest in these volcanoes is not limited to geology. Scientists from multiple disciplines are investigating their relationship with the origin of life, the evolution of extreme ecosystems and climate change. The exploration of the types of volcanoes can offer valuable information about these processes.
In addition, in its surroundings there are deposits of metals such as iron, copper and zinc, essential to the technology industry. Deep-sea mining is beginning to be seen as a possibility, although it is attracting serious environmental debate due to the high risk of damaging poorly understood habitats.
Geologist Thierry Juteau points out that these areas could be key to obtaining the metals of the futureHowever, there is still much to be studied before deciding how to manage them sustainably.
How to protect these unique environments?
Despite their importance, submarine volcanoes are not adequately protected. Mining, pollution, and climate change threaten to irreversibly alter these delicate systems. Understanding the risks and opportunities associated with these ecosystems is essential for effective conservation.
To preserve them, it is key:
- Establish marine reserves that include active volcanic regions.
- Regulate deep-sea mining with strict environmental criteria.
- Invest in non-invasive technologies to explore the seabed.
- Promote environmental education and public awareness of its relevance.
As citizens, we can support ocean research and advocate for scientific and legal initiatives that ensure the preservation of these areas.
Underwater volcanoes not only shape the ocean floor, but They give life, destroy and transform at scales we are only just beginning to understand. They are the hidden heart of our planet, a dynamic, constantly evolving system that influences life on Earth more than we imagine. Studying them with depth and respect is essential to better understanding our present and ensuring a sustainable future for all.
