Volcanic Activity & the Atmosphere

Specification Point 8.18:
  • Recall that the gases produced by volcanic activity formed the Earth’s early atmosphere
  • The surface of the early Earth was molten for millions of years during which time there was no atmosphere surrounding the planet.
  • Eventually cooling began to take effect and allow for molten materials to slow and solidify forming land masses.
  • Volcanoes formed on the land masses and released gases from the Earth’s interior through violent eruptions.
  • Earth’s gravity prevented the gases from escaping into outer space and they formed the atmosphere.

Composition of Earth’s Early Atmosphere

Specification Point 8.19:
  • Describe that the Earth’s early atmosphere was thought to contain:
    a) little or no oxygen
    b) a large amount of carbon dioxide
    c) water vapour
    d) small amounts of other gases and interpret evidence relating to this
  • Analysis of the gases conserved in the fossil record has allowed scientists to perform studies of the composition of Earth’s early atmosphere.
  • It is thought that the atmosphere at that moment in Earth’s history was similar to that of Venus or Mars today, which consist mainly of CO2.
  • During a period of intense volcanic activity, large amounts of carbon dioxide and water vapour were released, as well as nitrogen, hydrogen, ammonia, methane and other gases.
  • The early atmosphere therefore contained mainly CO2 and water vapour.
  • There was little or no oxygen present.

Early Earth Volcanoes, Edexcel GCSE Chemistry

Volcanoes spewed out water, carbon dioxide and other gases from the Earth’s interior

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.