Protection Against Earthquake - Definition, Causes, Types, FAQs

Introduction of earthquake:
All over the world one of the most important natural disasters is an earthquake and causes an enormous loss of life and property. Proper policies and public opinion on disaster management are the necessity of the hour. This will protect us against losses and help to deal with these risks. Though, to decrease the destruction caused by these events, the earthquake disaster management committee or the earthquake management has laid some safety procedures.

Note: This article contains information about the earthquake essay, project on earthquake, disaster management project class 9/ disaster management project class 10.

Also read : NCERT Solutions for Class 8 Science Chapter 15- Some Natural Phenomena

What is Earthquake? Write a short note on earthquakes.

Earthquake meaning or earthquake definition is given as a sudden trembling or shaking of the earth that lasts a very short period. Seismic activity can cause enormous damage to dams, buildings, etc. They may also cause tsunamis, landslides, floods, and loss of life. It is caused by a disorder deep within the earth's crust.

All-natural earthquakes take place in the lithosphere. Seismic wave analyses provide a complete image of the layered interior. An earthquake is the tremor of the earth’s crust. It is caused because of the release of energy, that produces the waves that travel in all directions. The affluence of energy takes place along a fault. A fault is a clear break in the crustal rocks. Generally rocks along with a fault move in opposing directions.

What are the effects of the Earthquake/ consequences of earthquake?

Below is the impact of the earthquake:

• Ground shaking: Surface waves that are close to the epicentre are responsible for the earthquake. The intensity of ground shaking will depend on the local geology, duration, and distance.
• Harm to a man-made structure.
• An outbreak of fire and leaking of dangerous chemicals.

Also read -

• NCERT Solutions for Class 11 Physics
• NCERT Solutions for Class 12 Physics
• NCERT Solutions for All Subjects

Causes of an Earthquake

Earthquake natural disasters are caused because of the tectonic changes of the earth. The energy release creates waves that move in all directions. The point at which the energy is being released is known as the hypocentre or focus. Generally, it lies at a depth of 60 km. This causes a release of energy, and the energy waves move in every direction. The point on the earth's surface which is in the vertical direction above the focus is known as the epicentre. It is the first place to encounter the waves.

How are Earthquakes measured?

Earthquakes are being measured by the amount of energy or force they produced. Richter scale is used to measure it. American seismologists Charles F. Richter and Beno Gutenberg discovered Richter’s scale in 1935 which offers the quantitative proportion of a tremor’s size. The quake’s greatness is determined to exploit the logarithm of the tallness of the biggest seismic wave aligned to a scale by a seismograph.

The Richter scale was originally made to measure the extent of seismic tremors of moderate size ie. 3 to 7. By providing a number that would allow the size of one quake to be contrasted and another. Currently, seismographs might be customized to register Richter sizes, and current policies to estimate tremor size were created to deliver results that continue as before with those intentionally using the Richter scale.

On the primary Richter scale, the slightest tremors can be quantified at that the worth was close to zero on the seismograph of the time frame. Since today's seismographs can be used to identify seismic waves much more humble than those primarily picked for zero sizes, it is not impossible to quantify quakes having negative extents on the Richter scale. Each extension of one unit on scale focuses on a 10-overlap increase in the greatness of the quake. As such, numbers on the Richter scale are comparative to the normal logarithms of most risky wave amplitudes. Each expansion of one unit furthermore will deal with the arrival of around several times more energy than that handled by the past entire number on the scale.

Types of Earthquakes

The following illustrates the types of earthquakes

• Explosion earthquakes: The emergence of this kind of earthquake is artificial. High-density explosion like nuclear explosions is the main cause.
• Volcanic earthquake: The less common compared to the tectonic variety, these earthquakes take place after or before the volcanic eruption. It is triggered when magma leaves the volcano is filled by rocks being pushed to the surface.
• Collapse earthquake: This earthquake takes place in underground mines. The major cause is the pressure produced within the rocks.
• Tectonic earthquakes: The most frequent type of earthquake, is triggered by the movement of loose fragmented pieces of land on the earth’s crust is termed as tectonic plates.

What is the difference between Richter and seismograph scales?

The following illustrates the difference between the Richter and seismograph scale:

How do earthquakes affect humans?

Earthquakes can strike unexpectedly and without notice. An earthquake is a fierce and sudden shaking of the ground, triggered by movement among tectonic plates along a fault line in the earth’s crust. Earthquakes can lead to soil liquefaction, ground shaking, fissures, landslides, fires, avalanches, and tsunamis. The extent of disaster and damage caused by an earthquake depends on:

• intensity and duration
• magnitude
• the time of day that it happens
• the local geology
• the risk-management measures put in place
• building and industrial plant design and substances.

Between 1998-2017, earthquakes triggered almost 750 000 deaths on a global scale, more than half of all deaths linked to natural disasters. More than 125 million people have been affected by earthquakes during this period, which means that they were injured, made homeless, displaced, or evacuated during the emergency stage of the disaster.

NCERT Physics Notes:

• NCERT Notes Class 11th Physics
• NCERT Notes Class 12th Physics
• NCERT Notes For All Subjects

Protection Against Earthquakes

Earthquakes is unpredictable. So, the buildings in seismic zones/fault zones should be created so that they can resist significant tremors.

The following steps are to be followed as precautions of earthquakes.

If you are at home

1. Drop-down and take cover under the table or desk and hold on.
2. Stay at home until the tremors stop and make sure it is safe to exit.
3. Stay away from furniture or bookcases that can fall on you.
4. Stay away from windows. In a high-rise building, expect the sprinklers and fire alarms to erupt during an earthquake.

If you are outside

5. Find a clear spot away from trees, buildings, and power lines. Fall to the ground.

If you are in vehicle

6. If you are in a car, a bus, or any other enclosed vehicle, don't come out till the shaking stop. Ask the driver to drive gradually to a safe location.

Conclusion of earthquake: Conclusion is given along with the safety measures that are to be followed before and during the earthquakes.

Prevention of earthquake before the disaster:

• We must make a plan and prepare to be on our own for at least three days with a calamity supply kit which comprises the non-perishable food and water and the first aid substances as well and along with that copies of essential family documents.
• To know how to switch off utilities also.

During the Earthquake:

we can use the formula of Drop and the cover and hold

• If we are inside when we feel the ground shake so we are required to drop down to the ground.
• Then we can take cover that is under a sturdy piece of furniture or seek cover against it. That is we can say an inner wall and protect our neck and head with our arms. Then we can avoid the hazardous spots that are close to the windows which are hanging objects and then the mirrors or tall furniture. We can say that we can hold the position until the ground stops trembling and it is safe to move.
• If we are somewhere outdoors to get into the open then away from the power lines and trees as well away from buildings. We should be alert for falling rocks and other debris that could be loosened by the earthquake.

Also check-

• NCERT Exemplar Class 11th Physics Solutions
• NCERT Exemplar Class 12th Physics Solutions
• NCERT Exemplar Solutions for All Subjects