Mauna Loa

Definition

Mauna Loa is one of the Earth's largest active volcanoes, located on the Big Island of Hawaii. It is a shield volcano, characterized by its broad, gently sloping profile formed from low-viscosity basaltic lava flows. This unique shape contributes to the formation of extensive lava fields and features like lava tubes and craters, which are important aspects of volcanic landforms and products.

5 Must Know Facts For Your Next Test

1. Mauna Loa covers an area of approximately 2,035 square miles, making it the largest volcano on Earth by volume and area.
2. The summit of Mauna Loa reaches an elevation of about 13,681 feet above sea level, but its base extends deep below the ocean surface, making it even taller when measured from its underwater base.
3. Mauna Loa has erupted 33 times since its first well-documented eruption in 1843, with the most recent eruption occurring in November 2022.
4. The lava produced by Mauna Loa is primarily low in viscosity, allowing it to travel great distances and create extensive lava flows that can cover large areas quickly.
5. Mauna Loa is closely monitored by scientists due to its potential for explosive eruptions and the impact these eruptions could have on surrounding communities and ecosystems.

Review Questions

• Discuss the characteristics that define Mauna Loa as a shield volcano and how these characteristics influence its eruptive behavior.
  • Mauna Loa is defined as a shield volcano due to its broad and gently sloping profile created by the accumulation of low-viscosity basalt lava flows. This type of lava allows for fluid movement, enabling eruptions to produce extensive lava flows that can travel far from the vent. The gentle slopes reduce the likelihood of explosive eruptions compared to stratovolcanoes, although Mauna Loa's size and activity still pose significant risks to nearby areas during eruptions.
• Analyze the geological significance of Mauna Loa's composition and structure in relation to volcanic landforms.
  • The geological significance of Mauna Loa lies in its composition of primarily basaltic lava, which shapes its characteristic shield form. This composition results in the formation of various volcanic landforms such as extensive lava fields and lava tubes. These features not only provide insight into the volcanic processes at work but also help scientists understand the evolution of Hawaiian volcanism and the hazards associated with active volcanoes.
• Evaluate the potential impact of a major eruption from Mauna Loa on both local ecosystems and human populations in Hawaii.
  • A major eruption from Mauna Loa could have profound impacts on local ecosystems and human populations in Hawaii. The rapid flow of basaltic lava could destroy habitats, alter landscapes, and affect water sources through ashfall and pyroclastic flows. Additionally, communities near the volcano would face immediate risks from lava flows, ash fallout, and potential evacuations. The long-term effects could include changes in soil composition affecting agriculture and shifts in local wildlife populations due to habitat loss or alteration.

Related terms

Shield Volcano: A type of volcano with broad, gentle slopes formed primarily by the eruption of low-viscosity basalt lava.

Basalt: A fine-grained igneous rock that is commonly produced by the rapid cooling of basaltic lava, making up much of Mauna Loa's structure.

Lava Flow: The movement of molten rock (lava) that erupts from a volcano, which shapes the landscape and contributes to volcanic landforms.