What type of lava is found at Kilauea?

Science

Kilauea is one of the most active and well-known volcanoes in the world. Located on the Big Island of Hawaii, it has been erupting continuously since 1983, making it an ideal location for studying volcanic activity and the various types of lava that are produced. In this article, we will explore the different types of lava found at Kilauea and the characteristics that make them unique.

The Basics of Lava

Before diving into the specific types of lava at Kilauea, it is important to understand the basics of lava itself. Lava is molten rock that is expelled from a volcano during an eruption. It is formed when the temperature of solid rock becomes hot enough to melt and turn into a liquid state. Lava flows downhill due to gravity and can cause destruction in its path, including burning and burying everything in its way.

Composition of Lava

The composition of lava can vary depending on the type of volcano it originates from. The two main types of lava are basaltic and silicic, with basaltic lava being the most common. Basaltic lava is rich in iron and magnesium, which gives it a dark color and a relatively low viscosity. On the other hand, silicic lava is rich in silica and has a higher viscosity, making it thicker and more explosive when it erupts.

Basaltic Lava

Basaltic lava is the type of lava that is predominantly found at Kilauea. It is characterized by its low viscosity, which allows it to flow easily and cover large areas. This type of lava has a high temperature ranging from 1,000 to 1,200 degrees Celsius and has a relatively low gas content. As a result, basaltic lava eruptions are generally not as explosive as those involving silicic lava.

Types of Basaltic Lava

Within the category of basaltic lava, there are several subtypes that can be found at Kilauea. These include pahoehoe, aa, and pillow lava.

Pahoehoe Lava

Pahoehoe lava is a smooth, ropy lava flow that has a low viscosity and can travel long distances. It forms when the surface of the lava flow cools and solidifies, while the molten lava underneath continues to flow. The result is a wrinkled, undulating surface that resembles twisted ropes or braids. Pahoehoe lava is typically found in areas where the lava flow is slow and not obstructed by obstacles.

Aa Lava

Aa lava is a more rough and jagged type of basaltic lava. It has a higher viscosity than pahoehoe lava, which causes it to move slower and develop a clinkery surface. Aa lava flows are characterized by their blocky appearance, with sharp, angular fragments that can be difficult to walk on. This type of lava is often found in areas where the flow has been disrupted by obstacles or changes in topography.

Pillow Lava

Pillow lava is a unique type of basaltic lava that forms underwater. When lava erupts into the ocean or any other body of water, it cools rapidly and solidifies into pillow-like structures. These pillows stack on top of each other, creating a distinctive and rounded appearance. Pillow lava is an important indicator of volcanic activity underwater and can be found along the coastlines of volcanic islands.

Silicic Lava

While basaltic lava is the dominant type of lava at Kilauea, there are also instances of silicic lava eruptions. Silicic lava is much thicker and stickier than basaltic lava due to its higher silica content. This type of lava is associated with explosive eruptions and can result in the formation of volcanic domes, pyroclastic flows, and ash clouds.

Rhyolitic Lava

Rhyolitic lava is the most common type of silicic lava found at Kilauea. It has a high silica content and is extremely viscous, making it difficult for the gas bubbles to escape. As a result, rhyolitic lava eruptions can be highly explosive, producing ash clouds, volcanic bombs, and pyroclastic flows.

Obsidian

Obsidian is a type of volcanic glass that is formed when silicic lava cools rapidly. It is characterized by its smooth, glassy texture and can come in a variety of colors, including black, brown, and red. Obsidian is often used in jewelry making and has been utilized by ancient civilizations for tools and weapons.

Volcanic Activity at Kilauea

Understanding the types of lava at Kilauea is closely linked to the volcanic activity that occurs there. Kilauea is a shield volcano, which means it has a broad, gently sloping shape resembling a warrior’s shield. The eruptions at Kilauea are predominantly effusive, meaning the lava flows steadily and continuously rather than explosively.

Historic Eruptions

Kilauea has a long history of eruptions, with some of the most notable ones occurring in recent decades. The ongoing eruption that began in 1983 is the longest and most voluminous eruption since records began in 1823. It has produced extensive lava flows, destroyed homes, and dramatically reshaped the landscape of the surrounding area.

The 2018 Lower Puna Eruption

In May 2018, a significant eruption occurred at Kilauea’s East Rift Zone, resulting in the destruction of hundreds of homes and the evacuation of thousands of residents. This eruption produced both basaltic and silicic lava, with the latter being responsible for explosive eruptions and the formation of volcanic domes.

The Impact of Lava Flows

When lava flows from Kilauea, it can have a profound impact on the surrounding environment. It can destroy vegetation, cover roads and infrastructure, and even create new land. The lava flows from Kilauea have extended the coastline of the Big Island by several miles over the past few decades.

Effects on Wildlife

The rapid and destructive nature of lava flows can have devastating effects on wildlife. Animals that are unable to escape the path of the lava are often killed, and their habitats are destroyed. However, some species have adapted to survive in volcanic environments and can recolonize the area once it has cooled.

Impact on Human Settlements

The eruptions at Kilauea have had a significant impact on human settlements in the vicinity. Homes and infrastructure have been destroyed, forcing residents to evacuate and seek shelter elsewhere. The economic impact of these eruptions can be long-lasting, as communities rebuild and recover from the destruction.

Conclusion

Kilauea is home to a diverse range of lava types, with basaltic lava being the most common. The low viscosity and high temperature of basaltic lava allow it to flow easily and cover large areas, while silicic lava is much thicker and more explosive. Understanding the types of lava found at Kilauea is crucial for studying volcanic activity and the impact it has on the surrounding environment. By studying the different types of lava, scientists can gain valuable insights into the inner workings of volcanoes and potentially predict future eruptions.

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