1. Volcanoes and Earthquakes Overview

2. Think back to the video you watched about volcanoes… What were some of the vocabulary words you heard? Vents Dormant Ring of FireMagma Eruption

3. What is a volcano? A volcano is an opening in Earth’s crust that releases lava, steam and ash when it erupts (becomes active). The openings are called vents. Mt. Kilimanjaro

4. Climbing volcanoes… Are you crazy? You need to know if the volcano is dormant. Scientists try to predict when volcanoes will erupt. If they are not scheduled to erupt anytime soon, they are called dormant volcanoes.

5. What causes volcanoes to erupt? Volcanoes can be formed when rock surfaces beneath the earth’s crust are pushed together. The rock that is pushed down as a result gets closer to the earths core. What does this cause? The part of the crust that is pushed down is heated by the earth’s core, and melts becoming magma Eventually, there is so much magma that it is forced up through the opening of the volcano (called the…) Vent! This process is called an eruption

6. Is there a pattern to where volcanoes are located? Many volcanoes a re located sporadically (randomly placed along the tectonic plate convergences.) But one area in particular is very populated with volcanoes … any guesses for its name? The RING OF FIRE! Most of the volcanoes in the Ring of Fire occur at subduction zones.

7. Do people live around volcanoes? 20111999

8. What is an Earthquake? A special machine called a seismograph is used to measure earthquakes. Seismographs are attached to bedrock (The solid rock underneath soil and looser rock) A seismograph tells us there is an earthquake when the bedrock vibrates There are many different levels of earthquakes, which are measured on the Richter scale. We describe an earthquake in Richter Magnitudes.

9. The Richter Scale… Richter MagnitudesEarthquake EffectsEstimated Number per year <2.0Generally not felt, but recorded 600 000 4.0-4.9Felt by most6 200 6.0-6.9Destructive in populated regions 266 7.0-7.9Major earthquakes, which inflict serious damage 18 >8.0Great earthquakes, which produce total destruction to communities near the source 1.8

10. What happens during an earthquake? Seismic waves c ause ground-shaking movement These are the energy waves that travel outward from the source of the earthquake These aftershocks are actually just smaller earthquakes, and they cause damaged buildings to collapse The Kobe earthquake in Japan produced over 600 aftershocks

11. Are there different kinds of (seismic) earthquake waves? Primary (P) Waves - travel fastest and can pass through solids, liquids and gases. Cause a slight vibration that would rattle dishes on shelves. These warn people that an earthquake is happening, and give people a few seconds to prepare. Secondary (S) Waves - Travel more slowly. Can pass through solids only. Surface waves - Slowest of the three. Rolling motion breaks up roads and buildings, so they do the most damage. They move like ripples moving away from a stone that has been thrown into water.

12. How can you locate an earthquake? When there is a thunderstorm, how do you know how far away from you it is? Just like that, the farther apart the P and S waves a re, the farther away the earthquake. The place deep in the crust where the earthquake begins is called the focus o f the earthquake. If you go straight up to the earth’s surface from the focus, this point is called the epicentre. P and S waves t ravel out from the focus. Surface waves (on the surface) travel out from the epicentre.

14. How do rocks move during an earthquake? Just like when we talked about mountains, the Earth’s crust is always under pressure These stresses can cause the rock to bend and stretch. But what happens when the pressure is too great? It causes a fault. Movement along a fault can spread more than a kilometer in a second!!! Remember: Fault zones are where tectonic plates m eet! Think back to the web interactive when we looked at the different kinds of faults: normal, reverse and strike- slip/transform.

15. Earthquake Video http://www.learnalberta.ca/content/ngs/index.html?I D1=&action=v&video=whentheearthquakes_seg1_eart hquakesdest.smil