Basaltic lava

Definition

Basaltic lava is a type of low-viscosity lava that is primarily composed of basalt rock, characterized by its fluidity and relatively low gas content. This type of lava flows easily from volcanic eruptions, often creating broad, gently sloping shield volcanoes. The relationship between basaltic lava and plate boundaries is significant, as it is commonly associated with divergent plate boundaries and hotspots, where the magma rises to the surface due to tectonic activity.

5 Must Know Facts For Your Next Test

1. Basaltic lava typically has a temperature ranging from 1,000 to 1,200 degrees Celsius (1,832 to 2,192 degrees Fahrenheit).
2. Due to its low viscosity, basaltic lava can flow over great distances, leading to extensive lava fields and large volcanic landforms.
3. Basaltic lava eruptions tend to be less explosive compared to other types of lava, such as andesitic or rhyolitic lava.
4. Many of the world's most active volcanoes, like those in Hawaii and Iceland, are primarily fed by basaltic lava due to their locations at divergent plate boundaries or hotspots.
5. The composition of basaltic lava includes high levels of iron and magnesium and low levels of silica compared to other types of magma.

Review Questions

• How does the composition and viscosity of basaltic lava influence its behavior during volcanic eruptions?
  • Basaltic lava's low viscosity allows it to flow easily compared to more viscous lavas. This characteristic results in less explosive eruptions because gases can escape more readily during the eruption. Consequently, basaltic lava typically produces broad shield volcanoes rather than steep stratovolcanoes, which are formed by more explosive eruptions associated with higher viscosity lavas.
• Discuss the role of divergent plate boundaries in the formation of basaltic lava and associated volcanic features.
  • At divergent plate boundaries, tectonic plates move apart, allowing magma from the mantle to rise to the surface. This process often leads to the formation of new oceanic crust through the eruption of basaltic lava. As this lava flows out and solidifies, it creates extensive underwater features like mid-ocean ridges or landforms such as shield volcanoes on land, significantly shaping the Earth's geological landscape.
• Evaluate the impact of basaltic lava flows on the surrounding environment and human activities.
  • Basaltic lava flows can have both destructive and constructive impacts on the environment. While they can destroy habitats, infrastructure, and agricultural land during eruptions, they also create new landforms that can enrich soil over time. In areas like Hawaii, communities have adapted to living near active volcanoes by developing monitoring systems for eruptions and utilizing geothermal energy from volcanic heat, demonstrating resilience and innovation in coexistence with these natural phenomena.

Related terms

Shield Volcano: A type of volcano built up almost entirely from low-viscosity basaltic lava, resulting in a wide, gently sloping shape.

Magma: Molten rock located beneath the Earth's surface, which can emerge as lava during a volcanic eruption.

Divergent Boundaries: Plate boundaries where two tectonic plates are moving apart, often resulting in volcanic activity and the formation of new oceanic crust.