Inside a Volcano: The Journey to Earth’s Fiery Core

Audience: Elementary and Middle School Students

Did you know around 80% of Earth’s surface, both land and seafloor, was formed by volcanic activity? Photo by Toby Elliott from Unsplash. 

Imagine being asleep for hundreds, maybe even thousands of years. Just think about all the energy you’d have stored up during that period of time. Like the classic saying goes: you could probably run a marathon after that much sleep. Well, believe it or not, there’s actually something on Earth that stores energy exactly like that: volcanos. Some volcanoes can stay dormant, or in other words inactive for centuries, building up pressure the whole time. However, when they finally wake up from their years worth of “sleep” they don't just let out a yawn and have a little stretch. Instead, they erupt with extensive amounts of force. But, before we dive into how these powerful forces erupt, it's important to understand what a volcano actually is. Volcanoes are openings in the earth's surface, through which molten rock, ash, and gases can escape from deep inside the planet's core. Volcanoes are far from just a pretty sight to look at or something out of a science-fiction movie; they are powerful forces of nature capable of transforming their surroundings, whether through means of destruction or enrichment.

Volcanoes stories start deep beneath the Earth's surface where intense heat and pressure begin to melt solid rock into a hot and glowing liquid called magma. Magma is essentially melted rock, also known as molten rock, and it can reach unbelievable temperatures ranging from about 650°C to 1250°C. Magma is found deep inside the earth's center, also known as the earth's mantle. The mantle is a thick layer of rock found between the Earth's outer crust and its inner core. Unlike the solid rock that we live on, the mantle is hot and constantly moving. As the magma continues to collect in the mantle, the gases trapped within the earth's surface begin to expand. Over time, this rising pressure becomes so great that it can make an eruption more explosive. While everything brews beneath the surface, Earth's crust tries to act as a lid for volcanos. However, as the pressure from the rising magma and gasses become too strong, the crust begins to weaken. This weakening forms cracks and openings, which provide pathways for the magma to move upward. Eventually, these pathways will reach the surface, allowing the magma to escape, along with the built up gasses and ash. The eruption occurs once the magma finally forces its way through the cracks in the Earth’s crust. As it reaches the surface, it releases lava, ash, and gases, producing the explosive or flowing event that we know as a volcanic eruption. 

Now that we’ve learned a little about what volcanoes are, let's discuss the different types of volcanoes. The first type of volcano we’ll be discussing is cinder cone volcanoes, which are the most common type of volcano in the world. Cinder cone volcanoes are relatively small compared to the other types and are often short-lived; they usually only erupt once or a few times. Cinder cone volcanoes are built from particles of lava called cinders, which pile up around the volcanoes opening to form a steep, cone-shaped hill. The next type is called the shield volcano. These are volcanoes that have wide openings and gentle slopes, allowing the lava to flow out of them slowly. Due to their shape, eruptions from shield volcanoes are generally less violent, and the lava spreads out gradually rather than blasting into the air. Lastly, we will discuss stratovolcanoes, also known as composite volcanoes. Stratovolcanoes are tall and steep, with layers of hardened lava, ash, and rock built up over many eruptions. Their shape and thick, sticky lava make their eruptions extremely explosive and dangerous. These eruptions often send ash clouds and other volcanic materials spewing out. 

No matter what the specific effect is, every volcanic eruption will impact its surrounding area, and its effects can range from short-term to long-term. In the short-term, lava flow and ash can destroy everything in their path, including forests, homes, and farmlands. The ability of volcanoes to devastate local ecosystems is why they are often viewed in such a negative light. Large eruptions can also affect the climate by sending ash and gases high into the atmosphere. These particles block sunlight, which can lead to the temporary cooling of the Earth, causing unusual weather patterns in the area, such as colder summers. Additionally, the gases released during eruptions like carbon dioxide can contribute on a larger scale to global warming. However, volcanoes aren't entirely bad. When volcanic ash settles on the ground, it slowly begins to break down and release a variety of minerals into the soil. This helps make the soil in the surrounding area very fertile. This fertile soil not only helps plants grow faster, but it also supports the entire ecosystem by allowing forests, crops, and other vegetation to thrive in the area surrounding the volcano over the long term. 

In conclusion, volcanoes are some of the most powerful and fascinating forces of nature that can both destroy and develop areas. Their ability to transform the earth’s surface shows how closely connected the planet's geological activities are to life on Earth. While their eruptions can be dangerous and unpredictable, they also play a vital role in shaping ecosystems, enriching soil, and even influencing climate patterns. Understanding the science behind volcanoes helps us prepare for their dangers, while also deepening our appreciation for the incredible forces of nature that help shape our modern world as we know it. 

Bibliography

CDC. “Preparing for a Volcanic Eruption.” Volcanoes, 14 May 2024, www.cdc.gov/volcanoes/safety/index.html. Accessed 14 Sept. 2025.

National Geographic. “Human and Environmental Impacts of Volcanic Ash | National Geographic Society.” Education.nationalgeographic.org, National Geographic, 27 Sept. 2022, education.nationalgeographic.org/resource/human-environmental-impact-volcanic-ash/. Accessed 14 Sept. 2025.

National Park Service. “Types of Volcanoes - Volcanoes, Craters & Lava Flows (U.S. National Park Service).” Www.nps.gov, 12 Dec. 2022, www.nps.gov/subjects/volcanoes/types-of-volcanoes.htm. Accessed 14 Sept. 2025.

---. “Volcanic Eruptions - Volcanoes, Craters & Lava Flows (U.S. National Park Service).” Www.nps.gov, 18 July 2022, www.nps.gov/subjects/volcanoes/volcanic-eruptions.htm. Accessed 14 Sept. 2025.

USGS. “How Can We Tell When a Volcano Will Erupt?” Usgs.gov, 2019, www.usgs.gov/faqs/how-can-we-tell-when-a-volcano-will-erupt. Accessed 14 Sept. 2025.

---. “How Do Volcanoes Erupt?” Usgs.gov, USGS, 2019, www.usgs.gov/faqs/how-do-volcanoes-erupt. Accessed 14 Sept. 2025.

Volcano Hazards Program. “About Volcanoes | U.S. Geological Survey.” Www.usgs.gov, www.usgs.gov/programs/VHP/about-volcanoes. Accessed 14 Sept. 2025.

---. “Volcanoes Can Affect Climate | U.S. Geological Survey.” Www.usgs.gov, 2015, www.usgs.gov/programs/VHP/volcanoes-can-affect-climate. Accessed 14 Sept. 2025.