EARTHQUAKE BY Muhammad Usama FA 18 CVE012 WHAT

EARTHQUAKE BY Muhammad Usama FA 18 -CVE-012

WHAT IS EARTHQUAKE? Any sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks. Earthquakes often occur along geological faults and narrow zones where rock masses move in relation with each other.

CAUSES

BOMBING Very heavy bomb with a delayed detonation would cause damage to a target through shock waves travelling through the ground, hence the nickname earthquake bombs.

MOVEMENT OF TECTONIC PLATES Earthquake is caused by the multi directional movement of tectonic plates under the earth crust which causes outer surface to fluctuate from its position.

RELEASE OF ENERGY Earthquake is caused by the sudden release of stored energy that creates seismic waves. Seismic waves are caused due to the movement of rocks under the earths crust.

MEASUREMENT

RICHTER SCALE Magnitude is a measure of the amount of energy released during an earthquake. The richter scale was invented by Dr. Charles Richter in 1930. This scale is numbered from 1 to 10. The machine used for measuring earthquake is called seismometer.

MOMENT MAGNITUDE METHOD The moment magnitude scale is based on the total moment release of the earthquake. It is derived from modeling recordings of the earthquake at multiple stations.

EFFECTS

SHIFTING OF LAND In an earthquake, the land can shift and move. Soil and rocks begin to slide down slopes, burying anything in their path. In colder places snow and ice move rapidly downhill too, in avalanches, causing lots of damage.

FLASH FLOODS Flash floods can occur if river banks are damaged by the shaking of the ground. Famously, earthquakes can also create huge, powerful waves called tsunamis, which can reach up to 30 or even 40 meters (100 -130 feet) in height when they crash onto the land.

EFFECTS ON PEOPLE People can be caught in collapsed buildings, killed or injured instantly or in the first few hours or days after a quake. Search and rescue teams race to reach people trapped under rubble, using sniffer dogs and specialistening equipment.

EFFECTS ON CIVIL ENGINEERING STRUCTURES Generally, the bigger, closer, and shallower the earthquake, the stronger the shaking. But there have been large earthquakes with very little damage either because they caused little shaking in populated areas, or because the buildings were built to withstand that kind of shaking.