ENVS 101 1st Edition Lecture 3 Outline of Last Lecture I. Exploration of the Earth’s four major Reservoirs, their interactions and what they are comprised of, as well as a fifth focus: The AnthroposhpereA. Definitions for: Atmosphere, Biosphere, Lithosphere, Hydrosphere, Anthroposphere, Cryosphere, Negative/Positive Feedback, CycleB. Overview of Energy and Fundamental Laws of ThermodynamicsC. Introduction to the modes of heat transferOutline of Current Lecture II. Introduction to Earth’s External and Internal energy sourcesIII. Comparison between various wavelengths (of light) present in the Earth energy cycle, as well as how the Atmosphere serves as a filter for certain types of energy coming towardsEarthIV. Definitions for: Fusion, Geothermal Gradient, Radiogenic Heat, Accretionary Heat, Albedo, Nebula, Relative Age, Numerical AgeV. Exploration of Earth’s energy cycle and the various roles of energy in the cycleVI. Energy usage, developments, and innovations in modern societyVII. Introduction to the evolution of the Solar System, as well as to Time and ChangeCurrent LectureAll processes that take place within the Earth system are driven by energy produced by both internal sources from the Earth’s interior, as well as by external sources. The Sun is by far the most prominent of external energy sources of the energy the Earth receives. The Sun is a star that radiates heat on account of the thermonuclear reactions that occur in its core. The nuclear reactions that occur inside stars (Sun included) involve fusion.- Fusion: The merging of lightweight chemical elements (hydrogen in particular), to form heavier elements like carbon or helium. The process of element formation via fusion occurs primarily in the cores of stars, and essentially converts matter into energy. Thus, fusion is a process which also takes place in extremely high temperatures, according to Einstein’s equation (in which energy = mass x the speed of light, as shown below):These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.E= mc2The energy that is released by the Sun when fusion takes place is primarily gamma rays (accounting for about 98% of the energy which is released), which are very short electromagnetic waves with a high energy content. Another energy released by the Sun throughfusion is in the form of neutrinos (which account for about 2% of the energy which is released), electrically neutral particles with no mass that move at the speed of light. From all of the energy released towards the Earth, our stratospheric ozone layer absorbs very short wavelength UV (ultraviolet) radiation. This energy is then transformed into heat, and warms this ozone layer (Jet-liners fly along the bottom layer of the stratosphere) essentially one layer of the atmosphere above us. The way in which the atmosphere acts as a filter for this type of radiation helps to remove some of the most energetic (and biologically harmful) radiation, part of what makes it possible for life to exist on the surface of Earth.Aside from the various types of external energy sources that the Earth has, there are also energy sources that come from the interior of the Earth itself.- Geothermal Gradient: The increase in temperature present within the deeperlayers of the Earth.Traveling towards the Earth’s core, the increase in temperature is enough so that the core reaches the temperature of the surface of the Sun (about 5000o C). Measurements also establish that where the heat flow from the interior to the Earth’s surface are greatest, there is also volcanic activity present (making volcanic activity a manifestation of the Earth’s internal energy source). The presence of hot springs also indicates an area of the Earth with a high geothermal gradient.Among the Earth’s internal energy sources is Radiogenic heat, which accounts for about 66% of the interior heat flow. - Radiogenic Heat: Heat produced from the Earth’s interior by the decaying of radioactive elements naturally occurring inside of the Earth. - Accretionary Heat: Internal heat which is left over from the origins of Earth and other planets of our solar system, when particles of many sizes collided with one another, and stuck together to form larger planetary bodies. Earth’s energy cycle is very much related to the concept of a “budget” of sorts. Energy in this cycle can be both added or subtracted, or even transferred from one storage reservoir to the other, but overall, these various interactions in the energy cyclemust balance. If balance within the system is not maintained, the Life Zone of the Earth must either heat up or cool down in response. Energy In: Incoming solar radiation powers the winds, and dominates the overall flow of energy into Earth’s energy budget, accounting for about 99.985% of the total. Part of this vast influx of energy powers the winds, rainfall, ocean currents, waves, and other processes of the hydrologic cycle. This solar radiation also powers the process of photosynthesis, which converts solar energy into chemical energy and temporarily storesthis chemical energy in the biosphere as organic matter. Earth’s internal heat energy alsoplays important role as the driving force behind the tectonic cycle, causing the lithospheric plates to shift, uplift mountains, and even cause earthquakes and volcanic eruptions.Energy Out: Earth loses energy by reflection (albedo), as well as by radiation. About 40% of solar radiation is reflected by the top of the atmosphere, clouds, ocean surfaces, continents, ice and snow found throughout the Earth. - Albedo: The percentage of incoming radiation that is reflected unchanged. A highalbedo means a highly reflective surface, thus, the Earth had a higher albedo during its most recent Ice Age than it currently does now. Absorbed solar radiation also undergoes irreversible degradations as a result of being transferred from one reservoir to another, eventually ending up as heat that is reradiated into space. Earth’s outgoing radiation is also selectively absorbed by gases inside the atmosphere, causing the greenhouse effect, which makes life possible on the surface of the Earth. Energy In Society: Humans tap into the continuous flows of energy present in the Earth’sreservoirs in order to extract the power needed for various modern day commodities such as transportation, home/office use, as well as