let's talk about the structure of the earth what's inside and how do we know the earth is made up of layers at the surface we have the crust under the crust is the mantle then we have the core which is divided into the outer core and the inner core let's talk about the crust first most people might assume that the crust is quite thick I mean it is the only thing separating us from boiling hot magma but nope the crust is the thinnest layer ranging between about six and seventy kilometers thick it's kind of like the skin of an apple in comparison to the rest of the Apple basically the crust is really really thin compared to the other layers the crust is also divided into two types continental crust and oceanic crust so what is the difference between the two continental crust forms our large land masses and it's what we live on oceanic crust on the other hand lies under the oceans basically when you look at Earth any large area of exposed land is continental crust and anything under the ocean is oceanic crust here are a few key differences between the two continental crust is thicker while oceanic crust is thinner as you can see in this diagram continental crust is older while oceanic crust is younger continental crust is less dense while oceanic crust is more dense this is because of their composition continental crust is mostly Granite made of silicates and aluminum also known as soil which is lighter than oceanic crust which is mostly Basalt and made of silicates and magnesium known as SEMA which is heavier next up we have the mantle this is the thickest of all the layers with a measurement of approximately 2 900 kilometers the mantle contains magma which is viscous kind of like a thick syrup it is not entirely solid or liquid so we can refer to it as semi-solid or semi-liquid in the mantle there is something called convection currents that drive the movements of the crust above it the heat from the core causes hot magma to rise up to the crust where it cools the magma then sinks back down to the bottom of the mantle where it is reheated these Cycles continue over and over again and play an important role in continental drift and activity at plate boundaries let's move on to our outer core which is about 2260 kilometers thick and made up of liquid iron and nickel it reaches temperatures between four thousand and five thousand degrees Celsius because the outer core moves around the inner core the Earth's magnetism is created now for the inner core it has a radius of 1220 kilometers which is slightly smaller than our moon the inner core reaches temperatures of about 5200 degrees Celsius to put that into perspective the surface of the Sun has a temperature of about 6000 degrees Celsius simply put our core is freaking hot even with all these high temperatures the inner core is a solid because of the high pressure it experiences from its surrounding layers now that we know what's inside our Earth let's talk about how we actually know this Methods at the surface level of our Earth have informed us of what the internal structure looks like we have used things like drilling studying different rocks studying volcanoes and looking at the composition of lava however scientists cannot draw further than the crust so we've had to explore other options when earthquakes occur they released seismic waves that reverberate through the Earth scientists can study how these waves Bend reflect speed up or slow down based on this they can determine if something is a solid or a liquid and how thick it is this data can then be mapped out and helps us understand what the internal structure of the earth looks like if you enjoyed this video or found it helpful I would love to see you in my next one so please click that red subscribe button down below thank you to everyone who likes and comments and subscribes it really really means so much to have you here with me I'll see you in my next video bye [Music] thank you