BIO SCI 2 - LESSON 2

• Aristotle observed Earth’s land composition changes at a slow rate
• Earth Systems Science (ESS) studies Earth as an integrated system, seeking to understand the past, current, and future state of our planet
• Sustainability refers to the capacity of Earth to support human life without depleting natural resources
• Notable scientists in Earth Science include Vladimir Vernadsky, Alexander von Humboldt, James Hutton, James Lovelock, and Lynn Margulis
• Earth Science includes four subsystems: Atmosphere, Biosphere, Lithosphere, and Hydrosphere
• The Atmosphere is composed of gases like Nitrogen, Oxygen, and Carbon dioxide
• The Atmosphere is divided into layers including the Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere
• The Geosphere (Lithosphere) is divided into three layers: crust, mantle, and core
• The Crust is the thinnest and outermost layer of the Geosphere, made of solid rocks and minerals like Fe, Na, Ca, Ti, Si, O, Al, K, H
• The Mantle is mostly made up of silicate rocks rich in magnesium and iron, contributing to plate tectonics, volcanoes, earthquakes, and mountain building
• The Core is the innermost layer of Earth, made up of iron and nickel, with two layers: the outer core (liquid state) and the inner core (solid state)
• Earth is a complex system consisting of living and nonliving components
• Earth Science is the branch dealing with the physical components of Earth, including Geology, Physics, and Atmospheric Science
• Earth System Science (ESS) studies Earth as an integrated system, aiming to understand the past, current, and future state of the planet
• Sustainability refers to Earth's capacity to support human life without depleting natural resources
• Noosphere is the sphere of human consciousness and reason
• Uniformitarianism states that geological forces in the past are the same as those in the present
• Gaia hypothesis proposes that Earth works as a self-regulating system
• Atmosphere consists of all the gases on Earth, derived from the Greek word atmos meaning gas
• Geosphere, from the Greek geo meaning ground, is divided into crust, mantle, and core
• Hydrosphere is the total water on a planet, including surface, underground, and the cryosphere, which is frozen water
• Biosphere is the zone where life exists, encompassing all living organisms and ecosystems
• Troposphere is where most of Earth's weather occurs and where clouds are generated
• Stratosphere houses Earth's ozone layer, protecting from UV rays
• Mesosphere is the coldest layer of Earth where most meteors burn up
• Thermosphere, where auroras are seen
• Exosphere is the uppermost layer of the atmosphere with gases like hydrogen and helium
• Crust is the thinnest, outermost layer of Earth made of solid rocks and minerals
• Mantle, the largest layer, is mostly silicate rocks rich in magnesium and iron
• Core, the innermost layer, is made of iron and nickel, with the inner core solid and the outer core liquid
• Asthenosphere is a ductile part of the upper mantle
• Oceanic crust is thinner and denser, making up the seafloor, while continental crust is thicker and less dense, forming continents
• Trenches are long depressions on the seafloor formed at tectonic plate boundaries where one plate subducts beneath another
• Volcanic arcs are chains of volcanoes above subduction zones
• Karman line separates the atmosphere and outer space
• Mohorovicic discontinuity is the boundary between the crust and mantle
• Bullen discontinuity separates the upper and inner core
• 1. S-waves and P-waves help identify the liquid state of the outer core
• Saltwater makes up 97.5% of Earth's water
• Ocean currents describe how water moves in the oceans