Hawaiian Volcanic Lava: Uniqueness and Diverse Characteristics

The unique geographical location and volcanic activity of Hawaii have contributed to the distinctive characteristics of its lava flows. Unlike other types of volcanoes, Hawaiian volcanoes predominantly erupt basaltic lava, which forms shield volcanoes such as Mauna Loa, Kilauea, and others. This article explores the differences in lava types found in Hawaiian volcanoes, the properties that make Hawaiian lava flows unique, and the various forms of lava that can be observed during eruptions.

Basalt Composition in Hawaiian Volcanoes

Hawaiian volcanoes are known for their basaltic lava, distinct from other volcanic types such as rhyolite and andesite. Basalt is a dark, iron and manganese-rich lava that is not differentiated through crystallization and re-working. It forms the majority of the Earth's ocean floors and is the primary type of lava produced by Hawaiian volcanoes.

The mafic lava produced by volcanoes such as Mauna Loa, Kilauea, and Mauna Kea all originate from the Hawaiian hotspot. As the lava cools, it forms basalt, a dark rock that is characteristic of the Hawaiian volcanoes. The lava's basaltic composition remains consistent regardless of the volcano or the speed of the eruption.

Different Types of Lava Flows

Hawaiian volcanoes produce two principal types of lava flows: pahoehoe and aa. Understanding these lava flow types is crucial for comprehending the diverse eruptions and landscapes formed by these volcanoes.

Pahoehoe Lava Flows

Pahoehoe lava flows are characterized by their smooth, ropy, or billowy surfaces. They are more fluid and less viscous than aa flows. Pahoehoe lava flows are formed when the molten lava flows are more fluid and solidify with a smooth, ropy or billowy surface. This type of lava flow is often associated with quiet, effusive eruptions, making it an important feature of Hawaiian volcanism.

Aa Lava Flows

Aa lava flows, on the other hand, are characterized by their rough, spiny, or rubbly surfaces with a massive interior. These flows form when the lava is moving at higher speeds, resulting in a rough texture. Aa flows are often more viscous and can form explosive eruptions, although Hawaiian volcanoes generally produce less explosive eruptions because of the low viscosity of their lava.

Chemical Composition and Geologic Significance

Basaltic lava flows in Hawaii can vary in chemical composition, but the majority of the lava flows are classified as olivine basalt or andesine andesite. These variations in chemistry can be influenced by factors such as the mixing of different magma types or the interaction of lava with other materials. The high level of viscosities and the unique geologic setting of Hawaii have contributed to the distinct nature of these lava flows.

The lava flows are crucial for understanding the geological history of the Hawaiian islands, as they provide valuable insights into the dynamics of the Hawaiian hotspot and the formation of the Pacific oceanic crust.

Related Resources and Further Reading

For more detailed information on Hawaiian volcanoes and their unique lava flows, it is recommended to visit the National Park Service and the Hawaiian Volcano Observatory websites. These resources offer extensive data, photographs, and video recordings of eruptions and lava flows, providing a comprehensive understanding of Hawaiian volcanism.

Key Sources:

National Park Service – Hawaiian Volcano Observatory –

Conclusion

Understanding the unique characteristics of Hawaiian volcanic lava is essential for comprehending the geological processes that shape the islands. The basaltic composition, diverse types of lava flows, and the factors that influence their formation provide valuable insights into the geology of Hawaii and the dynamics of volcanic eruptions.

References

1. USGS Hawaiian Volcano Observatory. (2021, June). 2. National Geographic. (2020, May 20). 3. (n.d.). 4. Hawai'i Natural History Association. (2021, August 12).