enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Earth's early atmosphere consisted of accreted gases from the solar nebula, but the atmosphere changed significantly over time, affected by many factors such as volcanism, impact events, weathering and the evolution of ...

  3. Paleoatmosphere - Wikipedia

    en.wikipedia.org/wiki/Paleoatmosphere

    A paleoatmosphere (or palaeoatmosphere) is an atmosphere, particularly that of Earth, at some unspecified time in the geological past.. When regarding geological history of Earth, the paleoatmosphere can be chronologically divided into the Hadean first atmosphere, which resembled the compositions of the solar nebula; the Archean second atmosphere (also known as the prebiotic atmosphere), which ...

  4. Pie chart - Wikipedia

    en.wikipedia.org/wiki/Pie_chart

    Pie chart of populations of English native speakers. A pie chart (or a circle chart) is a circular statistical graphic which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area) is proportional to the quantity it represents.

  5. Paleoclimatology - Wikipedia

    en.wikipedia.org/wiki/Paleoclimatology

    An influence of life has to be taken into account rather soon in the history of the atmosphere because hints of early life forms have been dated to as early as 3.5 to 4.3 billion years ago. [21] The fact that it is not perfectly in line with the 30% lower solar radiance (compared to today) of the early Sun has been described as the " faint ...

  6. File:Atmosphere gas proportions.svg - Wikipedia

    en.wikipedia.org/wiki/File:Atmosphere_gas...

    English: Gas proportions in the Earth's atmosphere. The proportion of water vapor (H₂O) is variable so it is not represented in this chart, however it averages about 1% in the troposphere . Deutsch: Volumenanteil der Gase in der Luft

  7. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    Early fluctuations in oxygen concentration had little direct effect on life, with mass extinctions not observed until around the start of the Cambrian period, 7] The presence of O 2 provided life with new opportunities. Aerobic metabolism is more efficient than anaerobic pathways, and the presence of oxygen created new possibilities for life to ...

  8. Archean - Wikipedia

    en.wikipedia.org/wiki/Archean

    Earth's atmosphere at this stage was somewhat comparable to today's atmosphere of Titan. [19] The Archean atmosphere is thought to have almost completely lacked free oxygen; oxygen levels were less than 0.001% of their present atmospheric level, [20] [21] with some analyses suggesting they were as low as 0.00001% of modern levels. [22]

  9. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [2] was a time interval during the Earth's Paleoproterozoic era when the Earth's atmosphere and shallow seas first experienced a rise in the concentration of free oxygen. [3]