Earthquakes Facts Shaking and trembling of the earths
Earthquakes Facts • Shaking and trembling of the earth’s crust. – Is an EVENT not a FORMATION on earth! • Stress builds up in the cracks in the ground – When the rock boundaries energy! slips/gives it releases • The waves travel in all directions • More than 1, 000 quakes occur a year • Earthquakes continue until all the energy is used up
Earthquakes Parts EPI CENTER • “ Energy travels from focus EPI” means outer • Point ABOVE where quake starts (focus) • most violent shaking occurs here! • FOCUS- underground point of origin The three main types of seismic waves are: P, S, & Surface (L) waves
Earthquakes Waves P Waves • Primary waves • Arrive first at the epicenter • Can travel through solids, liquids, & gases • They are push-pull waves • Travel in straight line
Earthquakes Waves S Waves • Secondary waves • Can travel through solids, but NOT through liquids & gases • Move in up-down motion
Earthquakes Waves • Surface (Land) waves • Slowest moving seismic waves • Travel on top of Earth’s surface • Cause most of damage to Earth – bend & twist the surface L Waves
Seismo-- • Seismic wave-earthquake waves • Seismo graph-measures and detects seismic waves • Seismo gram- Paper record of waves • Seismo logist- scientist who study earthquakes
How bad was the Quake? ? Richter Scale Mercalli Scale • a scale that determines intensity of Seismic waves • 10 levels measured on amount of damage caused • Above a 6 is very destructive • a scale that determines intensity of quake based upon people, damage, & loss • 12 levels measured on amount of damage caused
Ring of Fire an area of frequent earthquakes & volcanic eruptions surrounding the Pacific Ocean.
40, 000 km horseshoe shape Ring of Fire The Ring of Fire has 452 volcanoes 90% of the world's earthquakes occur along the Ring of Fire.
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