Gadgetory

I woke up this morning check the news like I always do and found at the New Zealand experienced a rather powerful earthquake a magnitude 7.8 which is bound to be revised just a little bit these aren't exact Sciences so what our earth quakes and why do they happen I'm a petroleum engineering major here at ul but I've taken about five or six geology courses they kind of go hand in hand we're gonna be drilling into the earth so we better know how the earth works and what we're drilling into but geology courses have been my favorite courses by far here at my University and that's kind of what I want to pay tribute to in this video I know I talk a lot about computers in this channel but I want to diversify my portfolio a little bit and discuss something a little off topic if you will give it a chance this is minute science we're gonna try to tackle the subject and all around three minutes so our earth is very much alive and active it has three distinct layers the crust the mantle and the core the core is divided into two sub layers the outer core which is comprised of a liquid iron and nickel and the inner core which is a solid iron and nickel the outer core spins around the inner core and produces a magnetic field that shields us from solar radiation as for the mantle common misconception I actually believe is for the longest time the mantle is not comprised of a liquid it's not just magma it's actually most of it is a solid rock that behaves plastically because it's under intense pressures and heat and on top we have the Earth's crust of course it's what we live on it's very brittle it doesn't move slowly over time like the mantle does it moves very quickly in short amounts of time that right there earthquakes earthquakes occur in the crust not in the mantle but the mantle influences where earthquakes occur and how frequently they occur take the Ring of Fire for example the Pacific Rim is constantly subducting under very light continental crust it's comprised mainly of granite whereas ocean crust is comprised more of gabbro basalts much denser so it sinks when it's pushed against something that's much lighter another example the entire western seaboard of south america is considered a subduction zone because the Nazca plate off to its West is subducting underneath the light granitic crust comprising the South American plate remember denser crust sinks that's how gravity works as this dense crust reaches the upper layers of the mantle what we call the asthenosphere it partially melts rises to the surface and creates volcanoes and what we call the Andes Mountains the Nazca plate is one of the fastest moving tectonic plates on earth moving at roughly 3 to 4 centimeters per year and I mean picture that doesn't sound like a lot of movement right but that's an entire slab of Earth moving that far every year in a decade or a century it definitely adds up it also builds up a lot of static friction remember the crust is not as ductile and malleable as the mantle is so it builds up a lot of tension over time and then snaps instantly and those snaps are what produce earthquakes so after a prolonged buildup of static friction over time that coefficient will be overcome and several earthquakes will occur around that zone of movement so there are essentially two mechanisms driving earthquake forces here on earth and they go hand-in-hand the first is convection the mantle is constantly moving even though it's not a liquid it's still moving it rises when it partially melts and it sinks when it solidifies so the mantle picture moving up and down it's moving down into the outer core where it's much hotter that rock melts and then Rises because it becomes less dense and then as it solidifies it becomes more dense and begins to sink back down again okay those convection forces occurring in the mantle move the crust above it now if the crust behave like the mantle did we wouldn't have earthquakes per se because the crust would just stretch and move in response to the forces acting underneath it but the crust is stubborn and brittle and often refuses to budge unless severe forces act on it over a prolonged amount of time building of stress and that coefficient of static friction at this point the crust gives in and slips along a fault line or plate boundary resulting in one severe earthquake followed by several aftershocks which is kind of just that plate settling into its new position hopefully you'll learn something from this video or at least enjoy the topic let me know if you want to see more videos like this or if I should move on to something else entirely this is Salazar studio thanks for learning with this you