Secondary Effects of Volcanoes
Geography: Cambridge International GCSE (2027 Exams), topic 4.3.3
Secondary Effects of Volcanoes
The secondary effects of volcanic eruptions include:
Volcanic winter
- Ash can cause a volcanic winter by entering the upper atmosphere and reflecting sunlight.
- This causes cooling of around 2-4oC.
- This can cause famine as crops don’t ripen.
Lahars
- Lahars (mudflows) can destroy everything in their path, including buildings, homes, workplaces.
Lost forests and farmland
- After an eruption, forests and farmland can be lost.
- This happened when Mt. Saint Helens erupted in 1980, where 9.4 million m3 of timber was lost.
Flooding and tsunamis
- Tsunamis can happen as a result of tectonic (relating to the structure of the Earth’s surface) activity.
- These cause flooding and salinisation (increasing the salt content) of land. This happens because seas inundate (flood) the land.
Infrastructure damage
- People may become homeless if their houses are damaged or destroyed.
- Roads and train lines may be blocked, harming the clean-up operation and the local economy.
- This can also disrupt tourism.
Increased soil fertility
- Once it has been broken down, ash can actually make fields become more fertile and better for growing crops.
Economic damage
- If a country's farmland, transport system and people are harmed, the country's economy is also likely to suffer.
Test yourself on Secondary Effects of Volcanoes
Which of these is a secondary effect of volcanoes?
Secondary effects of volcanoes