Environmental Hazards

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1. Environmental Hazards Presented By Ahmad Hassan University Of Engineering and Technology Lahore (FSD Campus) 2014-BT-TXT-03

2. Contents Introduction of environmental hazard Types of environment hazard Earthquake Types of earthquake weaves Volcano Causes Effects

3. Introduction of environmental hazard Environmental hazards is the state of events which greatly effects the surrounding and people’s health. This situation cause pollution and natural such as storm, earthquake and volcano.

4. What is Earthquake? A sudden movement of the earth's crust caused by the release of stress collected along faults or by volcanic activity

5. How Earthquake Happens? It caused by a sudden slip on a FAULT. Stresses in the earth's outer layer push sides of fault together. Stress builds up & rocks slips suddenly, releasing energy in waves that travel through the earth's CRUST & cause the shaking that we Feel during an earthquake.

6. Fault- earthquake A fault is a fracture along which the blocks of outermost major layer of the earth, on either side have moved relative to one another parallel to the fracture. Faults are classified to Strike-slip and Dip-slip faults (normal, reverse and thrust). What is the crust? The outermost major layer of the earth is called CRUST and ranging from about 10 to 65 km in thickness worldwide. The uppermost 25 km of crust is brittle enough to produce earthquakes.

7. Earthquake .

8. Epicenter and Focus

9. Types of Earthquake Waves Body Waves P-Waves (primary waves) S-Waves (secondary waves) Surface Waves L – Love Waves R – Raleigh Waves

10. Body Waves: P and S waves Body waves P or primary waves fastest waves travel through solids, liquids, or gases compression wave, material movement in the same direction as wave movement S or secondary waves slower than P waves travel through solids only shear waves - move material perpendicular to wave movement

11. Surface Waves: R and L waves Surface Waves Travel just length of the ground’s surface Slower than body waves; rolling and side-to-side movement Especially damaging to buildings

12. Tsunami Tsunami is a series waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow water

13. Tsunami .

14. How Measure The Earthquake Strength? 1. Magnitude & 2. Intensity 1. Magnitude: A measure of actual physical energy release at its source as estimated from instrumental observations. 2. Intensity: A measure of the felt effects of an earthquake rather than the strength of the earthquake itself.

15. Effects Fires Building collapse

16. Effects Rupture Liquification

17. Volcanoes A volcano is a vent that connects molten rock (magma) from in the Earth’s crust to the Earth's surface. The volcano includes the surrounding cone of erupted material Vent Magma Chamber

18. How and why do volcanoes erupt? Hot, molten rock (magma) is floating and will rise up through the crust to erupt on the surface. When magma reaches the surface it depends on how easily it flows and the amount of gas (H 2 , CO 2 , SO 2 ) it has in it as to how it erupts. Large amounts of gas and a high viscosity (sticky) magma will form an explosive eruption! Small amounts of gas and low viscosity magma will form an effusive eruption

19. Effusive Eruptions Effusive eruptions are characterized by outpourings of lava on to the ground.

20. Volcano .

21. Volcano Monitoring Seismicity Deformation Gas Output Remote sensing techniques These three things are the most important sign to an eruption.

22. What is volcano monitoring? As magma moves through the Earth’s crust it can alter it’s environment producing sign’s on the surface, these signs are called “precursors” to an eruption. Precursors include Increased earthquakes in the area means increased seismicity Swelling and cracking of the ground means deformation Change in the amount of chemistry of the gas coming out of the volcano Change in the groundwater levels and chemistry.

23. Volcano Flow However, the potential damage was reduced by spraying seawater onto the advancing volcano flows. This caused them to slow and stop away from the undamaged part of the town.

24. Volcano Flow It is not just explosive volcanic activity that can be hazardous. Effusive activity is also dangerous.

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