What are the effects of volcanic eruptions on humans?
If the ashfall is really heavy it can make it impossible to breathe. Lava flows are almost always too slow to run over people, but they can certainly run over houses, roads, and any other structures. Pyroclastic flows are mixtures of hot gas and ash, and they travel very quickly down the slopes of volcanoes.
When volcanoes erupt, they emit a mixture of gases and particles into the air. Some of them, such as ash and sulphur dioxide, have a cooling effect, because they (or the substances they cause) reflect sunlight away from the earth. Others, such as CO2, cause warming by adding to the the greenhouse effect.
- Magma rises through cracks or weaknesses in the Earth's crust. When this pressure is released, eg as a result of plate movement, magma explodes to the surface causing a volcanic eruption. The lava from the eruption cools to form new crust. Over time, after several eruptions, the rock builds up and a volcano forms.
- Volcanic eruptions emit water vapor and toxic gases into the atmosphere. Learn about the gases emitted from an erupting volcano, such as carbon dioxide, sulfur dioxide, hydrogen sulfide, hydrochloric acid and carbon monoxide and their effects in this video lesson.
- Volcanoes are openings in Earth's crust where magma from the mantle is able to flow out. Without volcanic eruptions, farming communities would not be able to grow food, certain building materials would not be available and our atmosphere would not have its oxygen-rich environment.
Updated: 17th October 2019