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1 Teaching notes Starter: With a photograph of a recent earthquake on the board, ask pupils to describe what the event must have been like. Images are easily available with a Google image search e.g. and Questions could include: How bad was it? How much damage was caused? What would they have felt had they been there? A second photograph in comparison could be shown. This starts the class thinking about how two people could describe the same image, and their expressions used to describe the extent of the damage is different. Student tasks: 1. A card sort is provided on the Student task 1 sheet. Students could be asked to place the cards in the correct order for the Mercalli scale. 2. The students could draw a visual Mercalli scale, which illustrates each level on the scale. A comprehensive description of each value is provided from the US Geological Survey at 3. Students could bring in thumbnail images of the damage caused by an earthquake. Working in groups they could place these photos on the Student task 3 sheet according to the damage they think they see. Further discussion: What is the most common intensity of earthquake reported on the news? Why? (Reason - Earthquakes low down on the scale don t make headline news unless they occur locally or are not felt; earthquakes of high intensity are very rare) At what level of intensity would you want to evacuate your home, and why? Extension question: This scale measures intensity, however frequently it is the magnitude of the earthquake which is reported. What is the difference between the two measurements? Does it matter? (Clues: the intensity may change depending on distance from the epicentre and a large magnitude earthquake in a sparsely populated area has a low Mercalli scale value.) Page 1 of 7

2 Student task 1 The Mercalli scale measures the intensity and the effects of an earthquake. It is different from the Richter scale. The scale uses 12 values in Roman numerals from I (hardly felt) to XII (total destruction). Cut and sort the 12 descriptions below into the correct order of the Mercalli scale. The disturbance is felt by many, and windows could be broken. Objects thrown from shelves if not secured. Most buildings are razed. Few masonry structures stand. Railway lines are deformed and destroyed along with many bridges. People can feel something, but may not realise that it is an earthquake. A stationary car may rock slightly. Damage can be seen in some of the poorly built structures. Some better built structures could have slight damage. Features such as chimney stacks may break off. Some disturbance, especially inside. Cracks may be heard. Some may feel it if outside, and could observe stationary vehicles rocking slightly. Buildings, especially poorly designed ones, may collapse. Better designed buildings may show signs of damage. Furniture could be moved, and tall structures such as monuments could collapse. Felt by all, with some damage seen. Plasterboard walls could crack. Damage is extensive, with objects being thrown into the air. Train tracks will be deformed. Buildings and foundations (both well build wooden framed houses and some masonry buildings) are destroyed. Hardly felt. Only felt by a few, especially those higher up in buildings. Damage is considerable in many different structures, with many buildings collapsed. Train tracks could be deformed Page 2 of 7

3 Student task 2 The Richter scale measures the magnitude of an earthquake. The Mercalli scale is different from the Richter scale as it records the intensity and the effects of an earthquake. The Mercalli scale uses 12 values in Roman numerals from I (hardly felt) to XII (total destruction). The lower numbers of the scale are the way in which the earthquake is felt by people. The higher numbers of the scale are based on observed damage. The 12 descriptions are provided below. For each value on the Mercalli scale, draw a picture to show the effects at that value. Mercalli scale value Description of effects I Not felt except by a very few under especially favourable conditions. II Felt only by a few persons at rest, especially on upper floors of buildings. III IV V Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated. Felt indoors by many, outdoors by few during the day. At night, some people are woken up. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably. Felt by nearly everyone; many woken up. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop Page 3 of 7

4 VI Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight. VII VIII IX Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. X Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Railway lines bent. XI Few, if any (masonry) structures remain standing. Bridges destroyed. Railway lines bent greatly. XII Damage total. Lines of sight and level are distorted. Objects thrown into the air. Adapted from the information from the US Geological Survey at Page 4 of 7

5 Hardly felt. Only felt by a few, especially those higher up in buildings. People can feel something, but may not realise that it is an earthquake. A stationary car may rock slightly. Some disturbance, especially inside. Cracks may be heard. Some may feel it if outside, and could observe stationary vehicles rocking slightly Page 5 of 7

6 The disturbance is felt by many, and windows could be broken. Objects thrown from shelves if not secured. Felt by all, with some damage seen. Plasterboard walls could crack. Damage can be seen in some of the poorly built structures. Some better built structures could have slight damage. Features such as chimney stacks may break off. Buildings, especially poorly designed ones, may collapse. Better designed buildings may show signs of damage. Furniture could be moved, and tall structures such as monuments could collapse Page 6 of 7

7 Damage is considerable in many different structures, with many buildings collapsed. Railway lines could be deformed. Railway lines will be deformed. Buildings and foundations (both well build wooden framed houses and some masonry buildings) are destroyed. Most buildings are razed. Few masonry structures stand. Railway lines are deformed and destroyed along with many bridges. Damage is extensive, with objects being thrown into the air Page 7 of 7