cycles of the earth
DESCRIPTION
Cycles of the Earth. Hydrological Cycle. Taxonomy of Clouds. Luke Howard (1772-1864), Britain. Fitzroy and the Weather Forecast. In the British Navy and responsible for weather reports Coined phrase Weather Forecast Convinced that barometer readings foretell tomorrow’s weather - PowerPoint PPT PresentationTRANSCRIPT
Cycles of the Earth
• Hydrological Cycle and Weather• Climate• Chemical Cycles• Ice Ages• Rock Cycle• Geological Time Scale
Hydrological Cycle
Taxonomy of Clouds
Luke Howard (1772-1864), Britain
Fitzroy and the Weather Forecast• In the British Navy and
responsible for weather reports
• Coined phrase Weather Forecast
• Convinced that barometer readings foretell tomorrow’s weather
• Committed suicide after he was ridiculed by the press and the Admiralty dropped the need for forecasting
Vice-Admiral Robert Fitzroy (1805-1865), Britain
High and Low Pressure
Cyclonic Circulation
Collision of Air Masses
Ocean Currents
Movement of the Air
Hadley cell named for George Hadley (1685-1768) tried to explain why trade winds seemed to flow to the west
Climate Conveyor
Global Climates
El Niño & Gilbert Thomas Walker
1868-1958; England & India
Chemical Cycle: Carbon
Chemical Cycle: Oxygen
Chemical Cycle: Nitrogen
Ice Ages
Evidence of Glacial Action
• Moraines• Glacial Till and Flour• Erratics• U-Shaped Valleys
Jean Louis Rodolphe Agassiz (1807-1873); Switzerland and USAProposed Europe had been subjected to an Ice Age (1837-1840)
Svante August Arrenius
• Developed theory of Greenhouse Effect to explain Ice Ages
• 1896 calculated how changes in CO2 concentration could change climates
1859-1927; Sweden
James Croll
• Used the formulas developed by Le Verrier on planetary orbital variations
• Developed a theory about orbital variations influencing the amount of snow
• Orbital eccentricity should cause ice ages on a 22,000 year cycle
• Largely dismissed by end of the 19th Century 1821-1890; Britain (Scotland)
Milutin Milanković
• Canon of the Earth’s Insolation: climates of the planets
• Explanation of changes in Earth’s climate by interactions of three planetary cycles 1879-1958 (a Serb) born
in Kingdom of Hungary and died in Yugoslavia
Milanković Cycles• Eccentricity of earth’s
orbit (Kepler’s theory) has a 100,000 year cycle from 0.005 (nearly circular) to 0.058 (mildly eliptical)
• Axial tilt has a 41,000 year cycle (tilt changing from 22.1o to 24.5o )
• Precession has a 23,000 year cycle (suggested by Hipparchus in 130 BCE)
Inference of Climate Based on Temperature Proxies
PollenTree ringsIce coresRatio of oxygen isotopesCoralsDiatoms and foraminifera
Rock Cycle1. Magma2. Crystallization (freezing)3. Igneous rock4. Erosion5. Sedimentation6. Sediments & sedimentary rock7. Tectonic burial and
metamorphism8. Metamorphic rock9. Melting
Defined by Hutton and Lyell and modified by John Tuzo Wilson (1908-1993), Canada.His Ph.D. advisor: Harry HessRock cycle explained by erosion and action of plate tectonics
Using Steno’s Laws, attempt to interpret geological strata by relative time
Jean Léopold Nicolas Frédéric Cuvier& Alexandre Brongniart
• Together studied geology of Paris basin• Defined concept of faunal succession• Theory of cycle of repeated catastrophes
Cuvier(1769-1832) France
Brongniart(1770-1847)France
William ‘Strata’ Smith• Surveyor• Strata of coal
mines and canals• Used principle of
faunal succession to define layers
• Life’s work: Geological map of England and Wales
1769-1839, England
A plate of Smith’s fossils
Roderick Impey Murchison, 1st Baronet
• Independently wealthy, urged by Humphry Davy to turn his focus to science
• Became interested in the geology of Wales, England, Alps, Russia, Scotland
• Helped define the Silurian, Devonian, and Permian Systems 1792-1871, Britain (Scotland)
Adam Sedgwick• Cambridge University faculty
(ordained in the Church of England)
• Defined Cambrian system• Worked with Murchison to
define Devonian in England and on the system in the Alps
• Charles Darwin was his student who helped to define the sequence of Cambrian rocks in Wales
1785-1873, England
Arthur Holmes• Pioneer of radiometric dating
(Uranium-Lead method). Wrote this in a book by the time he was 24.
• Provides absolute time to strata
• Showed the earth was more than 1 BY old (most geologists had accepted that the earth was only 100 MY old)
• Completed the Geological Time Scale in 1944
1890-1965; England
Geological Time Scale