Natural Hazard Midterm

What is natural hazard

It’s a dangerous natural event like a flood, earthquake, or storm that can harm people, property, or the environment.

Seven Main Areas of Human Security

Economic, Food, Health, Environmental, Personal, Community, Political.

Natural Hazards vs Human-made Hazards

Natural hazards come from nature (like hurricanes); human-made hazards are caused by people (like oil spills or nuclear accidents).

Name and briefly describe the four main types of natural hazards:

Atmospheric: Related to weather (e.g. hurricanes, tornadoes)

Hydrological: Related to water (e.g. floods, tsunamis)

Lithospheric: Related to Earth's crust (e.g. earthquakes, volcanoes)

Biospheric: Related to living organisms (e.g. diseases, locust swarms)

Impact of Natural Hazards on society, economics, and the enviornment

They can destroy homes and infrastructure, hurt economies, cause deaths, and damage ecosystems.

Importance of Studying Natural Hazards

Predicting hazards, reducing damage, saving lives, and improving emergency responses.

Natural Hazards and Sustainability

Understanding hazards helps build safer communities and use resources wisely.

How can governments and societies prepare for natural hazards?

Making emergency plans, building strong infrastructure, educating people, and monitoring risks.

Describe one recent natural disaster and explain its main effects.

In 2023, wildfires in Canada burned millions of acres, forced evacuations, caused poor air quality, and affected global weather patterns. The wildfires resulted in significant destruction of wildlife habitats, economic losses in affected areas, and health issues for residents due to smoke inhalation.

Fusion in Stars

When hydrogen atoms join under high pressure and temperature to form helium, releasing energy.

What is the Chandrasekhar Limit?

It’s the maximum mass (about 1.4 times the Sun’s) a white dwarf star can have before collapsing into a neutron star or a black hole.

Why is the synthesis of iron in a star and the formation of a supernova significant?

When a star makes iron, it can't produce more energy through fusion. The core collapses, causing a massive explosion called a supernova, spreading elements into space.

Formation of the Solar System

From a cloud of gas and dust called a solar nebula. Gravity pulled it together, forming the Sun in the center and planets from the leftover material.

Kardashev Scale

Measures a civilization's technological advancement based on energy use: Type I (planet), Type II (star), Type III (galaxy).

Solar Cycle

A repeating 11-year cycle where the Sun’s activity rises and falls, including sunspots and solar storms.

Sunspots

Dark, cooler spots on the Sun caused by strong magnetic fields linked to solar activity.

Solar Storms

Bursts of energy from the Sun, including flares and CMEs, affecting satellites, power grids and radio communications.

Coronal Mass Ejection (CME)

A massive burst of solar plasma released into space, that can cause geomagnetic storms on Earth.

Solar Hazard

Any solar activity like flares or CMEs that can disrupt satellites and power systems.

Explain ozone and ozone holes, and their connection with UV radiation.

Ozone is a gas in the atmosphere that blocks harmful UV rays. Ozone holes are areas with less ozone, letting more UV reach Earth, increasing health risks.

What is a gamma-ray burst, and what consequences would it have on the atmosphere?

A powerful burst of gamma rays from space that could destroy the ozone layer if it hits Earth.

Black Holes

Collapsed stars with gravity so strong that nothing can escape from them.

Impact of a Celestial Body

It’s when an object like an asteroid or comet crashes into a planet — it can cause explosions, craters, or even global disasters.

Asteroids

Rocky objects that orbit the Sun, mainly made of rock and metal.

Main Groups of Asteroids

Main Belt (between Mars and Jupiter), Trojans (share orbit with a planet), Near-Earth asteroids ( come close to Earth).

Location of Main Asteroid Belt

Between Mars and Jupiter.

What are comets and what gives them their tail?

Icy bodies that form tails when near the Sun due to vaporization of the ice.

Coma in a Comet

The fuzzy cloud around a comet’s nucleus, consisting of a gas coma (from evaporated gas) and a dust coma (from dust particles).

Oort Cloud

A spherical cloud of icy objects around the Solar System, where long-period comets come from.

Difference between Asteroids, Comets, and Meteors

Asteroids (rocky), Comets (icy with tails), Meteors (streaks of light when burning in atmosphere).

Meteoroids, Meteors, Meteorites

Meteoroid (small space rock), Meteor (burns in atmosphere), Meteorite (hits the ground).

Tunguska Explosion (1908)

A space object exploded over Siberia, flattening 2,000 km² of forest

Chelyabinsk Event (2013)

A meteor exploded over Russia, injuring about 1,500 people and damaging buildings.

What could happen if a large asteroid hit Earth?

It could cause fires, tsunamis, climate change, or even mass extinction — like what happened to the dinosaurs.

Probability of Globally Catastrophic Impact

Very low in the short term, but it’s possible over millions of years — that’s why scientists monitor space objects.

Detection of Near-Earth Objects (NEOs)

Using telescopes, radar, and space missions to monitor and predict impacts.

Stopping or Deflecting a Dangerous Asteroid

Use space missions to push it off course, like NASA’s DART mission, or explore options like nuclear devices or gravity tractors.