Why is it in the news?
- The recent eruptions at Mount Etna have led to flight cancellations at nearby airports.
- Mount Etna is Europe’s most active volcano and one of the largest in the world.
- Recorded volcanic activity at Mount Etna dates back to 1500 B.C., and it has erupted more than 200 times.
- Volcanoes are openings or vents where lava, tephra (small rocks), and steam erupt onto the Earth’s surface.
- They can be on land or in the ocean and usually form mountains from layers of rock, ash, or other materials.
- Volcanoes can be classified as active, dormant, or extinct.
- Active: Recently erupted or expected to erupt soon.
- Dormant: No recent eruptions but might erupt in the future.
- Extinct: Unlikely to erupt again.
Types of Volcanoes
- Four main types of volcanoes: Cinder cones; Composite or stratovolcanoes; Shield volcanoes; and Lava domes.
- The type depends on the lava flow characteristics and their impact on the volcano and its surroundings.
How Volcanoes Erupt
- Eruption characteristics depend on magma composition (silica content) and gas content.
- High silica magma is thick and leads to explosive eruptions.
- Low silica magma is thin and results in less explosive eruptions.
- Bubbles form in magma with lots of gas, making eruptions more explosive.
- Erupted magma is called
Effects of Volcanism
- On the Environment: Creation of volcanic landforms, impact on climate and weather patterns, habitat destruction, introduction of new species, and formation of new ecosystems.
- Health Threats: Suffocation, respiratory diseases, burns, skin irritations, food and water contamination, and disruption of basic services.
- Scientists can predict volcanic eruptions hours or days in advance using seismographic data from earthquakes and tremors as precursors.
|Volcanoes in the Pacific Ring of Fire|
· Many active volcanoes are located in the Pacific Ring of Fire, including New Zealand, Southeast Asia, Japan, and the western Americas.
· About 90% of worldwide earthquakes occur in this region.