[Music] welcome boys and girls today we're going to talk about the four spheres the geosphere the hydrosphere the biosphere and the atmosphere we will learn how these four spheres interact with each other and shape the natural world as we know it and to help us identify the four spheres let's bring in our friend ellie the elephant hi friends welcome to my watering hole okay let's start with the geosphere which is the outermost solid layer of the earth it's made up of the crust and the top part of the mantle sand rocks mountains canyons ocean floors and even magma are all part of the geosphere i have a friend with a geosphere collection actually it's just rocks but it sure sounds cooler when you call them geosphere the atmosphere is the layer of gases that surrounds the earth it's the air that animals like you and me breathe and that plants use for photosynthesis the atmosphere is made up of nitrogen oxygen argon carbon dioxide and other gases the atmosphere protects us from the sun's harmful ultraviolet rays and it also traps heat from the sun so i stay nice and warm sometimes a little too warm which leads me to the hydrosphere the hydrosphere contains all of the water on earth in liquid solid and vapor form about 71 of the earth's surface is covered in water but nearly all of that is salt water in the oceans and the seas most of the fresh water that does exist is frozen in the polar ice caps glaciers and icebergs with only a small amount of liquid water in the lakes reservoirs and rivers like this one where i spend most of my day and finally the biosphere makes up all of the living things on earth life exists all over the earth from the darkest depths of the ocean to the skies above the tallest mountains plants animals like me humans and even tiny bacteria and viruses are all part of the biosphere and those are the four spheres okay time for a swim thanks ellie have fun okay let's see how each sphere interacts with the others starting with the hydrosphere and the geosphere water shapes the geosphere through erosion and creates features like caves and waterfalls one of the best known examples of water erosion is the grand canyon a mild deep gorge carved by the colorado river over millions of years when large volcanoes erupt underwater the water cools the lava and solidifies it the lava rock builds up over time and sometimes emerges out of the water to form islands living beings in the biosphere need the hydrosphere to live plant roots absorb water for photosynthesis to create energy and the water also helps transfer nutrients from the soil to the plants animals like ellie need water to live humans use water for not just drinking but also cleaning farming cooking in industry and many other uses water mostly from oceans evaporates into the atmosphere as water vapor then condenses to form clouds and then falls back to the earth as rain or snow snow melts into rivers and rivers flow back into oceans this constant cycle shapes our climate transports minerals across the globe and provides us fresh water for drinking and farming now let's talk about the atmosphere and the geosphere magma which is part of the geosphere causes volcanic eruptions which expel gases and ash into the atmosphere the volcanic ash in the atmosphere can reflect sunlight away from the earth and can sometimes have a global cooling effect but volcanoes also release carbon dioxide which can raise global temperatures volcanic activity is thought to have caused and ended ice ages in earth's industry the atmosphere also shapes the geosphere through wind erosion winds erode dunes and transports sand from one place to another and over time even make grooves and hollows and rocks although far slower than water living beings need air to live animals use oxygen to generate energy and release carbon dioxide and as we've learned plants use carbon dioxide for photosynthesis and release oxygen into the atmosphere and finally let's talk about the geosphere in the biosphere many living beings including humans now live on the geosphere some live in burrows and caves to stay safe from weather and predators when plants and animals die their remains enrich the soil which then helps other plants grow humans mine the earth and use elements from the geosphere for a variety of purposes like iron for weapons and buildings or gold for decoration and currency and now you know all about the earth's four spheres and how they interact with each other to shape our world thanks for watching