Earth Science and its Components
– Earth science includes all fields of natural science related to the planet Earth.
– It deals with the physical, chemical, and biological constitutions and linkages of Earth’s four spheres.
– Earth science is a branch of planetary science with a long history.
– It involves reductionist and holistic approaches.
– Earth scientists use their knowledge to locate resources, study environmental impacts, and protect people from natural disasters.
– Geology is the study of Earth’s surface, including the crust and rocks.
– It incorporates aspects of chemistry, physics, and biology.
– Historical geology interprets Earth’s history and changes over time.
– Geochemistry studies the chemical components and processes of the Earth.
– Geophysics studies the physical properties of the Earth.
– Plate tectonics, mountain ranges, volcanoes, and earthquakes are geological phenomena explained by physical and chemical processes.
– The mantle, heated by radioactive decay, is in a state of semi-perpetual convection.
– Plate tectonics is the process of lithospheric plate movement.
– Divergent boundaries create new crust, convergent boundaries bring crust back into the Earth, and transform boundaries have sliding plates.
– Earthquakes result from the movement of lithospheric plates.
Atmospheric Science and Earth’s Magnetic Field
– Atmospheric science includes meteorology, atmospheric chemistry, and climatology.
– The atmosphere is composed of five layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
– Nitrogen, oxygen, argon, CO, and water vapor are the main components of the atmosphere.
– The greenhouse effect is caused by water vapor and CO, trapping the Sun’s energy.
– The atmosphere protects the Earth’s surface from cosmic rays and is shielded by the magnetosphere.
– Earth’s magnetic field extends from its interior into space.
– It protects the atmosphere from the solar wind.
– The magnetic field is generated by the core’s internal motions.
– The magnetosphere is created by the magnetic field and shields the atmosphere.
– The protective magnetosphere has prevented the loss of Earth’s atmosphere over billions of years.
– Generated by electric currents in Earth’s outer core.
– Magnitude ranges from 25 to 65 μT (0.25 to 0.65 G).
– Represented by a magnetic dipole tilted at an angle of about 11°.
– North geomagnetic pole represents the South pole of Earth’s magnetic field.
– Reversals of the geomagnetic poles leave a record in rocks.
Hydrology and Ecology
– Hydrology is the study of the movement of water on Earth.
– Includes subdisciplines like oceanography and hydrogeology.
– Hydrogeology involves mapping groundwater supplies and analyzing contaminants.
– Ecohydrology studies the effects of organisms and ecosystems on water.
– Glaciology focuses on the study of glaciers and the effects of climate change.
– Ecology is the study of how living things interact with the Earth and each other.
– Considers the use of resources by living things.
– Examines the changes caused by humans and other organisms.
– Part of the study of the biosphere.
– Includes the study of nature and ecosystems.
Physical Geography and Methodology
– Physical geography is the study of Earth’s systems and their interactions.
– Incorporates various fields like meteorology, geology, and biology.
– Includes the study of landforms, climate, and the atmosphere.
– Distinct from human geography.
– Considers human effects on the environment.
– Studies fall into observational, experimental, or theoretical categories.
– Earth scientists use computer analysis and field visits.
– Uniformitarianism is a foundational idea in Earth science.
– It states that ancient geologic features are interpreted by understanding present processes.
– Earth science recognizes four spheres: lithosphere, hydrosphere, atmosphere, and biosphere.
Geochemistry, Soil Science, and Additional Disciplines
– Geochemistry is the study of processes controlling abundance, composition, and distribution of chemical compounds and isotopes in geologic environments.
– Uses tools and principles of chemistry to study Earth’s composition, structure, and physical aspects.
– Major subdisciplines include aqueous geochemistry, cosmochemistry, isotope geochemistry, and biogeochemistry.
– Soil science covers the outermost layer of Earth’s crust subject to soil formation processes (pedosphere).
– Major subdivisions include edaphology and pedology.
– Covers interactions between organisms and their environment.
– Differentiates the study of Earth from other planets in the Solar System.
– Earth is the only planet teeming with life.
– Hydrology, oceanography, and limnology focus on movement, distribution, and quality of water on Earth.
– Involves all components of the hydrologic cycle in Earth’s atmosphere (hydrosphere).
– Subdisciplines include hydrometeorology, surface water hydrology, hydrogeology, watershed science, forest hydrology, and water chemistry.
– Glaciology covers icy parts of Earth (cryosphere).
– Atmospheric sciences cover gaseous parts of Earth’s atmosphere.
– Major subdisciplines include meteorology, climatology, atmospheric chemistry, and atmospheric physics. Source: https://en.wikipedia.org/wiki/Earth_sciences
