Lava dome

Definition

A lava dome is a mound-shaped protrusion formed by the slow extrusion of viscous lava, typically andesitic, dacitic, or rhyolitic in composition. These domes are created when lava accumulates near the vent of a volcano, solidifying and building up over time, often resulting in steep-sided formations. Lava domes are significant in understanding volcanic activity, as they can indicate ongoing eruptions and present unique hazards to surrounding areas.

5 Must Know Facts For Your Next Test

1. Lava domes can grow slowly over time and may collapse or explode if pressure builds up within them, leading to potentially dangerous events.
2. These formations can vary in size from small mounds to massive structures hundreds of meters wide and tall.
3. Lava domes are often found in stratovolcanoes, which are characterized by alternating layers of lava flows and pyroclastic deposits.
4. Monitoring lava domes is crucial for hazard assessment since their growth can signify volcanic unrest or the potential for more explosive eruptions.
5. Some well-known examples of lava domes include Novarupta's lava dome in Alaska and Mount St. Helens' lava dome formed after its 1980 eruption.

Review Questions

• How do lava domes differ from other volcanic features like craters and calderas in terms of formation and structure?
  • Lava domes are specifically formed by the slow extrusion of highly viscous lava that accumulates near a volcanic vent, resulting in a mound-shaped structure with steep sides. In contrast, craters are bowl-shaped depressions created by explosive eruptions, and calderas are larger depressions formed when a volcano collapses after a significant eruption. While both craters and calderas indicate past explosive activity, lava domes represent ongoing lava flow processes that may signal future eruptive events.
• Discuss the potential hazards associated with lava domes during volcanic eruptions and how they can impact surrounding areas.
  • Lava domes can pose several hazards during volcanic eruptions. As they grow, pressure may build up inside the dome, potentially leading to explosive events or collapse that can generate pyroclastic flows and volcanic ash clouds. The steep slopes of these domes can also lead to the rapid flow of molten material if they collapse, endangering communities nearby. Continuous monitoring of these features is essential to assess risk levels and implement safety measures for those living in proximity to active volcanoes.
• Evaluate the role of monitoring lava domes in predicting volcanic activity and mitigating associated risks to human populations.
  • Monitoring lava domes plays a crucial role in predicting volcanic activity because changes in size, shape, temperature, or gas emissions can indicate impending eruptions. By using techniques such as satellite imagery, thermal imaging, and ground deformation measurements, scientists can assess the growth patterns of these structures over time. This data is vital for risk mitigation strategies aimed at protecting human populations from potential hazards associated with eruptions. Enhanced forecasting allows for timely evacuations and emergency response planning to reduce loss of life and property damage.

Related terms

Volcanic eruption: A volcanic eruption is the release of gas, magma, and other materials from a volcano, which can take various forms such as explosive eruptions or effusive flows.

Pyroclastic flow: A pyroclastic flow is a fast-moving current of hot gas and volcanic matter that flows down the slopes of a volcano during an explosive eruption, posing severe hazards.

Crater: A crater is a bowl-shaped depression formed at the summit of a volcano as a result of explosive activity or the collapse of the land following an eruption.