Earthquakes Warm Up – 9-14 1. What is pyroclastic material? 2. Label the parts of the volcano to the right: 3. What is the most explosive type of volcano? 4. What is the difference between a crater and a caldera? Ring of Fire The Ring of Fire, also known as the circum-Pacific Belt is an area along the Pacific Plate where more than 75% of the world’s volcanoes are located (it also has a massive number of large Earthquakes) Earthquakes Earthquakes in 2017 so far…. Earthquakes Earthquakes are the shaking or trembling caused by the sudden release of energy Seismology Seismology is the study of earthquakes Seismologists utilize seismographs which can detect, record and measure earthquake waves on a seismogram First Seismograph Invented by Chang Heng in 132 A.D. (China) How Earthquakes Form As plates move across one another, they deform (bend) and store energy Eventually, the plates reach a point where the stored energy exceeds the strength of the plate and they will snap and then straighten out releasing the stored energy This is called the Elastic Rebound Theory Elastic Deformation Theory Imagine breaking a pencil… VIDEO Origin of Earthquakes The point within the Earth where the fracturing begins is called the focus or hypocenter This is actually below the surface of the Earth! The energy released travels in ALL directions Origin of Earthquakes Generally, the closer the focus is to the surface, the more destructive the Earthquake will be. Epicenter The epicenter of an Earthquake is the point on the surface of the Earth directly above the focus/hypocenter This is the most dangerous area to be around during an Earthquake! Ring of Fire Roughly 80% of the world’s earthquakes occur along the the Ring of Fire, also known as the circum-Pacific Belt Article Action! Articles Read through your article, and mark the following. Be prepared to share! _______ Underline/Highlight things you feel are important Put a square around any names that you see Put a circle around any words that you don’t use when you speak !! Put exclamation marks by things that surprised you Cool Volcano Video.