Zusammenfassung der Ressource
Volcanoes
- Formation of a volcano
- 1. Hot liquid rock called magma reaches the surface of
the ground through a narrow vent in the earth's crust.
- 2. It erupts violently, blasting lava, ash
and boiling mud into the air.
- 3. This material collects
around a vent in a cone shape.
- 4. Repeated lava flows add to this
cone-shaped mass of material.
- 5. Together the repeated ash and
lava layers build up to form a
cone-shaped mountain.
- Positive effects of volcanoes
- 1. New land is created for farming and
living space, e.g. Iceland.
- 2. Minerals are created by volcanic
activity. Lava soils are rich in minerals.
Good for growing crops.
- 3.Geysers(hot spring) can be formed and help
heat glasshouses for production of food. E.g.
Iceland.
- 4. Dormant or extinct volcanoes are major
centres of tourism. e.g Vesuvius in Italy.
- Negative effects of volcanoes
- 1. When snow-capped volcanoes erupt,
large mud flows are created, which often
cover villages and towns.
- 2. Gases from volcanoes may
kill people who live nearby.
- 3. Ash and lava flows can destroy
towns causing death.
- 4. Giant tidal waves are created by volcanoes at
sea. When they reach land they can kill people
especially in low-lying places such as deltas.
- Types of volcano
- Active
- Erupting regularly, e.g. Mount Helens in
California.
- Dormant
- Has not erupted in a long time. May
erupt again.
- Extinct
- Has not erupted over thousands of
years. Will most probably not erupt
again.
- Keywords
- Magma
- Geyser
- Vent
- ash
- Crater
- Pacific Ring of Fire
- Largest earthquake and volcano
zone is called the Pacific Ring of
Fire. It lies around the edge of the
Pacific Ocean.