SPHERES OF THE EARTH The area near the surface of the earth can be divided up into four inter-connected "geospheres:" the lithosphere, hydrosphere, biosphere, and atmosphere. Scientists can classify life and material on or near the surface of the earth to be in any of these four spheres. The names of the four spheres are derived from the Greek words for stone (litho), air (atmo), water (hydro), and life (bio). LITHOSPHERE The lithosphere is the solid, rocky crust covering entire planet. This crust is inorganic and is composed of minerals. It covers the entire surface of the earth from the top of Mount Everest to the bottom of the Mariana Trench. HYDROSPHERE The hydrosphere is composed of all of the water on or near the earth. This includes the oceans, rivers, lakes, and even the moisture in the air. Ninety-seven percent of the earth's water is in the oceans. The remaining three percent is fresh water; threequarters of the fresh water is solid and exists in ice sheets BIOSPHERE The biosphere is composed of all living organisms. Plants, animals, and one-celled organisms are all part of the biosphere. Most of the planet's life is found from three meters below the ground to thirty meters above it and in the top 200 meters of the oceans and seas. ATMOSPHERE The atmosphere is the body of air which surrounds our planet. Most of our atmosphere is located close to the earth's surface where it is most dense. The air of our planet is 79% nitrogen and just under 21% oxygen; the small amount remaining is composed of carbon dioxide and other gasses. All four spheres can be and often are present in a single location. For example, a piece of soil will of course have mineral material from the lithosphere. Additionally, there will be elements of the hydrosphere present as moisture within the soil, the biosphere as insects and plants and even the atmosphere as pockets of air between soil pieces. QUESTIONS: 1. Identify TWO ways that the spheres interact (or impact each other). Describe this interaction _ When two spheres love each over very much, they may choose to interact with each other, this can often result in the formation of a mini sphere that can’t yet operate on a global scale. _________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ 2. How are humans impacting each sphere? SPHERE HUMAN IMPACT Atmosphere Air pollution, emission of toxic gas Hydrosphere Water pollution, the dumping of non-degradable resources into bodies of water. Lithosphere Causing more erosion is causing the earth’s crust to alter. Biosphere We are killing each other on a daily basis 3. Which sphere do you think is MOST impacted by natural disasters (in general)? Justify your answer. Biosphere because we are the only sphere that is capable of understanding the impact, resulting in not just physical impact, but an additional mental toll. _________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ 4. How do cyclones impact each sphere? SPHERE CYCLONE IMPACT Atmosphere The destruction of bio-organisms such as trees releases extensive amounts of C02 into the atmosphere Hydrosphere Redistributes large volumes of water Lithosphere Waves break rock down = erosion Biosphere Kills people + animals + destroys habitats
