What are natural phenomena and how do they differ from disasters?

What causes earthquakes and how are they measured?

Earthquakes are caused by disturbances in the Earth's crust, primarily due to the movement of tectonic plates along seismic fault zones. They are measured on the Richter scale, which quantifies the magnitude of the seismic activity logarithmically.

Describe the safety measures that should be taken during an earthquake.

During an earthquake, individuals should seek shelter under sturdy furniture like a table if indoors, or move to an open area away from buildings and trees if outdoors. Buildings in seismic zones should be designed to withstand major tremors.

What are the terms 'hypocenter' and 'epicenter' in relation to earthquakes?

The hypocenter is the point below the Earth's surface where an earthquake originates, while the epicenter is the point directly above it on the surface.

Identify the earthquake-prone areas in India.

In India, earthquake-prone areas include Kashmir, the Western and Central Himalayas, the North-East region, the Rann of Kutch, Rajasthan, the Indo-Gangetic plains, and some parts of South India.

How have human activities contributed to climate change, and what is its relevance to natural disasters?

What is a landslide and what causes it?

A landslide is the rapid sliding of large masses of bedrock, which can be caused by factors such as earthquakes, sudden rock failures, or the over-steepening of slopes due to excavation or river erosion.

How is lightning produced during a thunderstorm?

What safety measures should be taken during a lightning storm?

During a lightning storm, one should avoid open areas, stay away from poles and metal objects, remain inside a car with windows and doors closed, refrain from using electrical appliances or phones indoors, and avoid contact with running water.

What is the purpose of a lightning conductor?

A lightning conductor is a device designed to protect buildings from lightning strikes. It consists of a metallic rod that is taller than the building, providing a safe path for electric charge to reach the ground.

What are the primary causes of floods?

Floods can occur due to heavy rainfall, the collapse of dams, storm surges, or unplanned development on floodplains.

What safety measures can be implemented to manage flood risks?

Safety measures for flood management include preventing deforestation, carrying out reforestation, constructing high walls and strong embankments along riverbanks, and using floodplains primarily for recreational or agricultural purposes.

What is a tsunami and how is it generated?

A tsunami is a series of ocean waves caused by large movements on the ocean floor, such as volcanic eruptions, landslides, or earthquakes.

What does the term 'tsunami' mean and what is its origin?

The term 'tsunami' is derived from a Japanese word meaning 'harbour waves'.

How fast can tsunamis travel and what factors influence their speed?

Tsunamis can travel at speeds of 600-800 km per hour, depending on the depth of the water.

Why are tsunamis less frequent in the Indian Ocean compared to the Pacific Ocean?

Tsunamis are less frequent in the Indian Ocean due to lower seismic activity compared to the Pacific Ocean.

What event caused the devastating Indian Ocean tsunami?

The devastating Indian Ocean tsunami was caused by a 9.0 magnitude earthquake near the Western boundary of Sumatra.

What is drought and how is it characterized?

Drought is a period of below-average precipitation in a given region, leading to prolonged shortages of water supply, both surface and groundwater. It can last from a few weeks to several years.

What are some primary causes of drought?

Primary causes of drought include scarcity of rainfall and inadequate monsoons, lack of irrigation facilities and rainwater harvesting systems, and deforestation which reduces soil water retention.

What safety measures can be taken to mitigate the effects of drought?

What causes the movement of wind in the atmosphere?

The movement of wind is caused by differences in atmospheric pressure, which result from the unequal heating of the Earth's surface by the sun, leading to warm air rising near the equator and cooler air moving from the poles.

What are the characteristics of a cyclone?

A cyclone is a violently rotating windstorm with wind speeds ranging from 120 to 200 km/h, characterized by a central area known as the eye, which has very low atmospheric pressure.

How do cyclones differ in terminology across regions?

Cyclones are referred to as hurricanes in America and typhoons in Asia, highlighting regional variations in terminology for this type of storm.

What are some of the states in India most affected by cyclones?

The states in India most affected by cyclones include Andhra Pradesh, Gujarat, Kerala, Maharashtra, Odisha, and Tamil Nadu, with the Eastern coast being more vulnerable than the Western coast.

What safety measures are recommended during cyclone threats?

Safety measures include installing a cyclone forecast system, heeding warnings from meteorological departments, and utilizing advanced technologies that allow for cyclone alerts 48 hours in advance and warnings 24 hours in advance.

What are man-made disasters and what causes them?

Man-made disasters are events caused by human error or negligence during technological and industrial activities. They can lead to significant loss of life and property, often occurring suddenly.

What are the two types of man-made disasters?

What is global warming, and what are its primary causes?

Global warming refers to the rise in Earth's overall temperature due to the increased concentration of greenhouse gases in the atmosphere, primarily from human activities like burning fossil fuels and deforestation.

What are the consequences of global warming?

Consequences of global warming include the melting of glaciers and ice caps, leading to flooding in low-lying areas and significant disruptions in climate patterns worldwide.

Explain the greenhouse effect and its role in global warming.

What is the function of the ozone layer?

The ozone layer functions as a protective shield in the Earth's stratosphere that absorbs about 99% of harmful non-ionizing UV rays from the sun.

At what altitude is the ozone layer located?

The ozone layer is located in the Earth's stratosphere at an altitude of 17 to 26 kilometers above the surface.

What are the primary causes of ozone layer depletion?

The primary causes of ozone layer depletion are the increased use of chemicals such as chlorofluorocarbons (CFCs), carbon tetrachloride, and halons.

Why is the depletion of the ozone layer a concern for the environment?

Depletion of the ozone layer is a concern because it leads to increased exposure to harmful UV rays, which can cause skin cancer, cataracts, and negatively impact ecosystems.