Skip to content

What is a volcanic island and why do they exist?

    What is a volcanic island? If you are asking yourself this question then you have come to the right place! In this article I will explain, in simple terms, what a volcanic island is and why they exist. Ready to learn more? Read on…

    What is a volcanic island?

    What is a volcanic island and why do they exist?

    A volcanic island is a special kind of island that is formed when a volcano erupts underwater and builds up a new piece of land above the water’s surface.

    It’s like a mountain that shoots out hot rocks, ash, and gases, and over time, these materials pile up to create an island.

    So basically, it’s an island that comes from an underwater volcano exploding and making new land- pretty cool, huh?

    How are volcanic islands formed?

    As I explained, volcanic islands are formed when volcanoes erupt underwater in the ocean.

    Here’s a simple explanation of how this process works:

    1. Underneath the Earth’s surface, there are tectonic plates that float on the semi-fluid layer called the mantle. These plates can move and interact with each other.
    2. Sometimes, two tectonic plates can collide with each other. When this happens, one plate can slide under the other, a process called subduction.
    3. During subduction, the plate that goes under gets pushed deep into the Earth’s mantle. As it moves deeper, the intense heat and pressure cause the plate to melt and form magma.
    4. The magma is less dense than the surrounding rock, so it starts to rise towards the Earth’s surface. Eventually, it finds a way to escape through weak points in the Earth’s crust, such as cracks or fractures.
    5. When the magma reaches the surface, it erupts as lava and other volcanic materials. This forms a volcano, which can be underwater or above the water level.
    6. If the volcano continues to erupt over a long period, the lava and volcanic materials accumulate and build up. Eventually, they can rise above the water’s surface and form an island.
    7. The volcanic activity continues to shape the island over time. As the lava cools and solidifies, it forms new land, and the repeated eruptions add more layers to the island. This process can create different types of volcanic landforms, such as steep cliffs, rocky shores, and fertile slopes.

    Real life examples of volcanic islands

    What is a volcanic island and why do they exist?

    Now that we know what a volcanic island is, lets focus on some real-life examples. Here are a few examples of well-known volcanic islands:

    Hawaii

    The Hawaiian Islands are a famous example of volcanic islands. They were formed by a hot spot in the Earth’s mantle, where a stationary plume of magma rises to the surface. As the Pacific tectonic plate moves over the hot spot, a chain of volcanic islands is created. The most well-known island in the chain is the Big Island of Hawaii, which is still an active volcano with its most recent eruption occurring in 2018.

    Iceland

    Iceland is located on the Mid-Atlantic Ridge, where the North American and Eurasian tectonic plates are spreading apart. This spreading causes magma to rise to the surface, creating a volcanic island. Iceland has a high concentration of volcanoes, and its landscape is shaped by volcanic activity, including eruptions, geysers, and hot springs.

    Krakatoa

    Krakatoa is an island in Indonesia, located in the Sunda Strait between the islands of Java and Sumatra. The original island of Krakatoa was destroyed in a massive eruption in 1883, which generated one of the most powerful volcanic explosions in recorded history. The eruption collapsed the volcano, creating a caldera, and later, a new volcanic cone emerged from the sea, forming the current island of Anak Krakatau.

    Santorini

    Santorini is a popular tourist destination in Greece and is part of the Cyclades island group in the Aegean Sea. It was formed by a series of volcanic eruptions over thousands of years. The most significant eruption occurred around 3,600 years ago, causing the centre of the island to collapse and forming a caldera. The remaining islands of Santorini, including Thera and Therasia, are the remnants of this volcanic activity.

    Jeju Island

    Jeju Island is a volcanic island located off the southern coast of South Korea. It is known for its unique volcanic landscapes, including the dramatic volcanic cones called Oreum, lava tubes, and volcanic craters. The island has several shield volcanoes, and the most famous is Mount Hallasan, a dormant volcano and the highest mountain in South Korea.

    These examples highlight the diversity and geological significance of volcanic islands around the world. Each island has its own unique features and history shaped by volcanic activity.

    Significance of volcanic islands

    What is a volcanic island and why do they exist?

    Volcanic islands hold significant importance in various aspects. Here’s a simple explanation of their significance:

    1. Biodiversity: Volcanic islands often have unique ecosystems that are rich in biodiversity. The isolation of these islands, combined with the arrival of new plant and animal species through ocean currents or migration, has led to the evolution of distinct and often rare species. These islands serve as hotspots for biological research and conservation efforts.
    2. Agriculture: The volcanic ash and lava deposits enrich the soil with minerals and nutrients, making it fertile for agriculture. Many volcanic islands, such as Hawaii and Iceland, have productive farmlands that benefit from the volcanic soil, allowing for the cultivation of crops like coffee, bananas, and vineyards.
    3. Tourism: Volcanic islands attract tourists from around the world due to their unique landscapes and geological features. Visitors are drawn to the scenic beauty, volcanic craters, lava fields, hot springs, and geothermal activity. Tourism contributes to the local economy, providing employment opportunities and promoting cultural exchange.
    4. Geothermal Energy: Volcanic islands often have geothermal energy potential. Geothermal power plants harness the heat from underground volcanic activity to generate electricity and provide heating for homes and industries. This renewable energy source reduces reliance on fossil fuels, leading to a more sustainable and environmentally friendly energy production.
    5. Scientific Research: Volcanic islands provide valuable opportunities for scientists to study volcanic processes, plate tectonics, and the Earth’s geology. Monitoring volcanic activity on these islands helps in understanding volcanic eruptions, predicting volcanic hazards, and developing early warning systems to protect local communities.
    6. Cultural and Historical Importance: Volcanic islands often have a rich cultural and historical significance. Indigenous communities living on these islands have developed unique traditions, folklore, and practices connected to the volcanoes. Historical eruptions and volcanic events have shaped the local history, leaving behind archaeological sites, ancient settlements, and cultural heritage.

    Understanding the significance of volcanic islands allows us to appreciate their natural beauty, protect their delicate ecosystems, utilise their resources sustainably, and learn from their geological and cultural heritage.

    What is life like for people living on volcanic islands?

    Life for people living on volcanic islands can be both challenging and unique. Here’s a simple discussion about what it’s like:

    1. Natural Beauty: People living on volcanic islands are surrounded by breathtaking natural beauty. They wake up to stunning views of volcanic landscapes, lush vegetation, and often have access to pristine beaches and crystal-clear waters. The unique geological features create a distinct atmosphere that residents can appreciate every day.
    2. Tourism and Economy: Tourism plays a significant role in the lives of people on volcanic islands. Many of these islands attract a large number of visitors who come to explore the volcanic landscapes, enjoy outdoor activities, and experience the local culture. This tourism industry provides employment opportunities, stimulates the economy, and contributes to the livelihoods of residents.
    3. Agriculture and Farming: Volcanic islands often have fertile soil due to volcanic ash and lava deposits. This makes agriculture a crucial part of the local economy. People engage in farming activities, growing crops like fruits, vegetables, coffee, or cultivating vineyards. They make use of the volcanic soil’s rich nutrients to produce high-quality agricultural products.
    4. Environmental Hazards: Living on a volcanic island means being aware of the potential risks and hazards associated with volcanic activity. Eruptions can occur, and people need to be prepared for such events. Governments and communities often have systems in place to monitor volcanic activity, issue warnings, and ensure the safety of residents. Regular drills and emergency response plans are important aspects of life on these islands.
    5. Geothermal Energy: Some volcanic islands have geothermal energy resources, which can be harnessed for electricity generation and heating. This renewable energy source can provide benefits to the local community, such as lower energy costs and reduced dependence on fossil fuels.
    6. Cultural Heritage: Volcanic islands often have a rich cultural heritage deeply intertwined with the volcanoes. Indigenous communities may have traditional beliefs, customs, and practices associated with volcanic activity. Volcanoes may hold spiritual or mythical significance for the local population, and cultural events and festivals may celebrate the volcanoes and their history.
    7. Close-knit Communities: Living on a volcanic island often means being part of a close-knit community. The isolation and unique environment can foster a strong sense of community among residents. People rely on each other for support, and there is often a strong bond and a shared identity tied to their volcanic home.

    While life on a volcanic island can present challenges related to volcanic activity, the natural beauty, economic opportunities, and strong community ties make it a distinctive and rewarding place to live. The resilience and adaptability of the people contribute to a vibrant and unique way of life.

    How volcanic islands evolve overtime

    What is a volcanic island and why do they exist?

    Did you know that volcanic islands gradually change? I saw this for myself when I travelled in the Galapagos Islands and I was amazed by what I saw!

    Here’s a simple discussion on the evolution of volcanic islands over time:

    1. Formation: Volcanic islands are formed through volcanic activity when magma rises to the Earth’s surface through cracks or weak points in the ocean floor. As the magma erupts and cools, it builds up layers of solidified lava and volcanic materials, gradually creating a new landform above the water’s surface.
    2. Primary Succession: Once a volcanic island emerges, it is initially devoid of life. However, over time, organisms such as plants, birds, and insects begin to colonise the barren landscape. This process is known as primary succession. Wind, ocean currents, or birds bring seeds and spores to the island, and as these pioneer species establish themselves, they create habitats for other plants and animals to thrive.
    3. Ecosystem Development: As the volcanic island continues to support life, ecosystems begin to develop. Plant life takes root in the volcanic soil, adapting to the unique conditions and often exhibiting high levels of endemism. Birds, insects, and other animals find food and shelter in the vegetation, creating a diverse ecosystem. Marine life around the island also flourishes, with coral reefs forming near the shores.
    4. Erosion: Over time, the volcanic island undergoes erosion due to natural forces such as wind, waves, and weathering. The exposed volcanic rock is gradually worn away, causing the island to change in shape and size. Erosion can create distinctive landforms like cliffs, sea stacks, and beaches. The erosion process is accelerated during storms or by the continuous action of waves crashing against the coastline.
    5. Subsidence and Submergence: As erosion continues, the volcanic island may undergo subsidence, which is a gradual sinking of the landmass. This subsidence can be caused by the weight of the accumulated volcanic material, the cooling and contraction of the underlying magma chamber, or tectonic processes. Eventually, the subsided island may sink below the water’s surface, becoming a seamount or an underwater feature.
    6. Reabsorption: Once submerged, the eroded volcanic island begins to dissolve and reabsorb into the sea over an extended period. The volcanic materials break down and mix with the surrounding seawater. This process is known as submergence or marine erosion. Eventually, only traces of the original volcanic island may remain, such as submerged volcanic remnants or seamounts.

    The evolution of volcanic islands from their formation to erosion and submergence is a natural and ongoing process. While the lifespan of an individual volcanic island can vary, this cycle is part of the dynamic nature of our planet’s geology and is observed in the geological history of many volcanic island chains around the world.

    What is a volcanic island and why do they exist?

    Key takeaways

    Now that we know all about volcanic islands, lets summarise the key facts:

    1. Formation: Volcanic islands are formed through volcanic activity when magma rises to the Earth’s surface through cracks or weak points in the ocean floor.
    2. Unique Landscapes: Volcanic islands often exhibit unique and dramatic landscapes, including volcanic cones, lava fields, calderas, and hot springs.
    3. Biodiversity Hotspots: Volcanic islands can be home to unique ecosystems and a high concentration of endemic species due to their isolation and the arrival of new plant and animal species.
    4. Fertile Soil: Volcanic ash and lava deposits enrich the soil, making it fertile for agriculture. Many volcanic islands have productive farmlands and grow crops like fruits, vegetables, and coffee.
    5. Geothermal Energy: Some volcanic islands have geothermal energy resources, allowing for the generation of electricity and heating using the heat from underground volcanic activity.
    6. Tourism and Economy: Volcanic islands attract tourists from around the world due to their natural beauty and geological features. Tourism plays a significant role in the local economy, providing employment opportunities and contributing to the livelihoods of residents.
    7. Environmental Hazards: Living on a volcanic island comes with the awareness of potential volcanic hazards, such as eruptions and associated risks. Monitoring systems and emergency response plans are important for ensuring the safety of residents.
    8. Cultural and Historical Significance: Volcanic islands often have a rich cultural and historical significance, with indigenous communities having traditions and practices connected to the volcanoes. Historical eruptions shape local history, leaving behind archaeological sites and cultural heritage.
    9. Evolution and Erosion: Over time, volcanic islands undergo erosion due to natural forces such as wind, waves, and weathering, eventually leading to subsidence and submergence back into the sea.
    10. Resilience and Community: People living on volcanic islands often develop a strong sense of community and resilience, relying on each other for support in the face of potential natural hazards and embracing the unique environment they call home.

    These takeaways provide a glimpse into the fascinating aspects of volcanic islands, highlighting their geological, ecological, cultural, and socioeconomic significance.

    Volcanic islands- FAQs

    To sum up this article, here are 10 frequently asked questions about volcanic islands along with their answers:

    How are volcanic islands formed?

    Volcanic islands are formed when volcanoes erupt underwater in the ocean, and the accumulated lava and volcanic materials build up over time, eventually rising above the water’s surface.

    What causes volcanic eruptions on islands?

    Volcanic eruptions on islands are caused by the movement of tectonic plates, where magma from the Earth’s mantle rises to the surface through cracks or weak points in the ocean floor.

    Are all volcanic islands still active?

    No, not all volcanic islands are active. Some volcanic islands become dormant or extinct, meaning they no longer have volcanic activity. However, others can remain active and experience eruptions.

    Are volcanic islands dangerous to live on?

    Volcanic islands can pose risks due to potential volcanic hazards, such as eruptions, ashfall, and lava flows. However, with proper monitoring systems and preparedness measures, living on volcanic islands can be relatively safe.

    Can volcanic islands sink back into the sea?

    Yes, over time, volcanic islands can undergo erosion, subsidence, and eventually submergence back into the sea. This process is a natural part of the life cycle of a volcanic island.

    Are there any unique plants and animals found on volcanic islands?

    Yes, volcanic islands often have unique and endemic species that have evolved in isolation. These islands can be biodiversity hotspots with diverse plant and animal life found nowhere else on Earth.

    Can volcanic islands be used as sources of renewable energy?

    Yes, some volcanic islands have geothermal energy resources. Geothermal power plants can harness the heat from underground volcanic activity to generate electricity and provide heating.

    Can you swim in the waters around volcanic islands?

    Yes, swimming in the waters around volcanic islands is generally safe, but it’s important to be aware of potential hazards such as strong currents or volcanic gas emissions, depending on the specific location.

    Do people live on all volcanic islands?

    Not all volcanic islands are inhabited. Some are remote and inaccessible, while others are populated by local communities or have developed into tourist destinations with larger populations.

    How do volcanic islands contribute to tourism?

    Volcanic islands attract tourists due to their unique landscapes, volcanic features, geothermal activity, and cultural heritage. Tourism provides economic benefits, supports local businesses, and promotes cultural exchange.

    To conclude

    As you can see, volcanic islands are found around the world and are a natural phenomena. They also change over time- so two volcanic islands can look very different!

    If you enjoyed reading this article, I am sure you will like these too: