introduction: the earth system

• Sedimentary rocks can be further classified into clastic (formed by the accumulation of fragments), chemical (formed through precipitation), and organic (formed from the remains of organisms).
• Metamorphic rocks include slate, schist, gneiss, marble, quartzite, and amphibolite.
• The main spheres of the earth are:

  • atmosphere
  • cryosphere
  • biosphere
  • geosphere

  The geosphere can be broken further into:

  • lithosphere
  • asthenosphere
  • remaining mantle
  • outer and inner core
• Heat and mass are transferred through the Earth System due to various processes.
• Energy and mass transfer from one reservoir to another is a fundamental process in the Earth System.
• The principal controls that drive the rock cycle are heat, pressure, and time.
• The rock cycle is a process that describes the changes rocks undergo as they move through the Earth System.
• A (bio)geochemical cycle is the process by which matter and energy move through the Earth System.
• The main spheres of the Earth System are the lithosphere, hydrosphere, atmosphere, and biosphere.
• The Earth is a differentiated planet, with five main Earth “spheres” (debatably four): Cryosphere, Hydrosphere, Biosphere, Geosphere, and Atmosphere.
• The Earth System is driven by two major interacting cycles: the Rock Cycle, driven by the Earth’s internal heat, and the Hydrological Cycle, driven by the sun’s energy.
• Geochemical cycles are the cycle of mass (elements) between the different Earth spheres (or reservoirs).
• Geochemical cycles happen for the following main reasons: heat is unevenly distributed, Earth spins, Earth revolves around the sun on a plane, Earth is tilted, Earth is not spherical and not materially heterogeneous.
• These effects generate temperature and pressure gradients in the Earth System.
• Mass and energy move through gradients in the Earth System.
• Mass can be moved to a new position where new temperature/ pressure profile cause it to become unstable.
• Phase or chemical reactions from materials with different physical properties are aided by gravity.
• The Hydrologic Cycle describes how water flows through the Earth System.
• The Rock Cycle is the concept that rocks change their physical and chemical properties when they are forced out of their equilibrium conditions.
• Changes in T and P, mainly driven by tectonics, aid the Rock Cycle.
• The Rock Cycle is aided by the hydrological cycle, gravity, and sometimes life.
• The Earth System is differentiated, with a Lithosphere, Asthenosphere, Remaining mantle, Outer and inner core.
• The Earth is 500 km thick at the surface, 6300 km thick at the center, and makes up 29% of the total mass of the Universe.
• The study of flow behaviour in the Lithosphere, Asthenosphere, Outer Core and Inner Core is more useful for understanding tectonics and the Rock Cycle.
• Peridotite has a density greater than 3.3g/cm3.
• The hydrosphere includes the oceans, which cover 70% of the Earth’s surface, and the hydrosphere, which includes groundwater, lakes, rivers, and glaciers.
• Some sediment is made from weathered and eroded rock, while some isn’t, and they are made and go to different places.
• Atmospheric chemistry involves understanding the composition and properties of the atmosphere, including the ozone layer.
• The composition and vertical structure of the atmosphere can be described as follows: the atmosphere is composed of nitrogen, oxygen, argon, and other gases, with a mean molecular weight of 28.96g/mol, and has a vertical structure that varies from the equator to the poles.
• Weathering and erosion are processes that occur on the Earth’s surface, changing the Earth’s landscapes and seascapes.
• The mature (eroded) continental crust is composed of granitic rocks with a density of 2.8g/cm3.
• Docking of continents, orogenesis, is a process that results in the formation of mountains.
• The global climate and circulation work by transporting heat from the equator to the poles, with the oceans playing a significant role in this process.
• Weather forecasting involves predicting the weather for a specific location, and can be learned by anyone.
• The overlying lithosphere is rigid enough to comprise a number of relatively coherent plates, that move relative to each other as a result of asthenospheric deformation – it is brittle.
• The volume and location of ice have changed over geological time due to processes such as glaciation and sea-level changes.
• Tectonic cycles are the processes that occur over geological time.
• Conservative tectonic processes result in little change in lithospheric thickness.
• The lithosphere is 30-70 km thick.
• The oceans work by circulating water, transporting heat, and influencing the climate.