Exploring Volcanoes

What Is a Volcano?

A volcano is a mountain constructed by the eruption of molten rock from Earth's interior. Volcanoes are a direct consequence of plate tectonics and mantle convection. Volcanoes and humans have a long history of interaction, some peaceful and some deadly. Volcanoes are unpredictable and dangerous natural phenomena. Some volcanoes are peaceful sleeping giants, while others can erupt with devastating consequences.

Volcano Formation

The eruption of molten rock from Earth's interior causes the construction of a mountain known as a volcano. Volcanoes are formed when magma rises to the surface, creating vents and eventually erupting. The molten rock, ash, and gases released during eruptions shape the volcano's structure over time. Some famous volcanoes include Mount Vesuvius, Mount Fuji, and Mount St. Helens.

Volcanic Eruptions

Volcanoes are powerful and unpredictable natural phenomena. They release volcanic gases, pyroclastic debris, and lava flows. Volcanic gases include H₂O, CO₂, and SO₂, which can have significant impacts on the environment. Pyroclastic debris consists of fragments blown out of a volcano, while lava flows are molten rock that moves over the ground. Basaltic lava flows, characterized by low silica and viscosity, can flow rapidly and cover long distances.

Volcanic Gas:

SO₂ is a gas released by volcanoes that can have significant impacts on the environment. It contributes to the formation of acid rain, which can harm plants, animals, and aquatic life. Additionally, SO₂ can cause respiratory problems in humans. Other gases released by volcanoes include H₂O (water vapor), CO₂ (carbon dioxide), and O₂ (oxygen).

Exploring Volcanoes:

• Lava Tubes: Conduits for basaltic lava

• How they form: As basalt flow moves, upper surface cools and crusts over. Flow continues beneath crust, thickening it over time. Tubes can be miles long.

• Benefits of lava tubes: Prevent cooling, facilitating flow for miles. After volcanic episodes, tubes become caves that can transmit water and attract tourists.

Lava Tubes

Trivia: Lava tubes are conduits for basaltic lava. They are formed when the outer surface of a lava flow cools and solidifies while the molten lava inside continues to flow. These natural tunnels can be several kilometers long and are often found in volcanic areas. Some lava tubes have even been converted into tourist attractions or used as shelter by humans and animals.

Types of Lava Flows

Pahoehoe is a Hawaiian word describing basalt with a glassy, ropy texture. It forms when extremely hot basalt forms a skin, which is rolled into ropy ridges and furrows. 'A'a is a Hawaiian word describing basalt that solidifies with a jagged, sharp, angular texture. It forms when hot flowing basalt cools and thickens, resulting in sharp, jagged shards and fragments that solidify into hard solid rock. Image of A'a is below.

​Types of Lava Flows

Pahoehoe: Hawaiian Basalt

Pahoehoe is the Hawaiian word for basalt with a glassy, ropy texture. It is formed when basaltic lava flows slowly and cools down, creating smooth, undulating surfaces. This type of lava is often found in Hawaii's volcanic landscapes. 'A'a is another type of Hawaiian basalt with a rough, jagged texture. A'ā is purportedly what people say when walking on this material barefoot.