Dumb ass Rock class

Why are natural hazards increasing worldwide?

Natural hazards are increasing worldwide primarily due to human-driven climate change, environmental degradation, and socioeconomic factors.

What is the history of the human population?

The human population grew slowly for hundreds of thousands of years as hunter-gatherers, before exploding exponentially after the agricultural and industrial revolutions 200,000 years ago: Homo sapiens first arose in Africa.

• 10,000 BC (Agricultural Revolution): The global population was estimated at 5 to 10 million people sustained by hunting and gathering. Mastering agriculture allowed communities to settle and grow.

• 1 CE: The world population reached approximately 170 million to 200 million people. [1, 2, 3, 4]

• 1346–1353 (The Black Death): Pandemics like the bubonic plague caused rare global population declines, killing tens of millions in Europe and Asia.

• 1700: Population growth began to pick up steadily as food supplies and trade networks expanded. [1, 2, 3]

The Industrial Revolution and Modern Explosion (1800 – Present)

• 1804: The world population reached one billion for the first time.

• 1927: Reached two billion people (taking 123 years to add the second billion).

• 1965–1970: The global population growth rate peaked at 2.1% per year.

• 2012: The human population hit seven billion.

• November 15, 2022: The United Nations estimated the global population exceeded eight billion.

• Present day (2026): The world population is approximately 8.3 billion, though overall annual growth rates have slowed to around 1% as global fertility rates decline. [1, 2, 3]

What are some of the natural services hazards can provide?

Natural Protection Services

• Shoreline Protection: Coral reefs and coastal marshes act as natural physical barriers.

• Wave Reduction: These coastal habitats slow down wind and wave energy during major storms.

• Water Absorption: Healthy vegetation and wetlands absorb excess rainwater and reduce heavy flooding.

What is the value of studying the history of natural hazards?

Studying the history of natural hazards provides critical data and context to understand Earth's physical processes, reduce avoidable risks, and design better community protections

What is the difference between direct or indirect effects from a natural hazard?

Direct effects from a natural hazard are the immediate, physical impacts caused directly by the event itself, while indirect effects are the secondary consequences that happen as a result of that initial destruction

What role does the Hydrologic Cycle play in geohazards?

The hydrologic cycle acts as the primary engine driving water-related geohazards by constantly moving water between the atmosphere, land surface, and subsurfaceC

How would you use the Scientific Method to solve a geologic question?

You use the scientific method in geology by turning field observations into testable explanations for Earth's complex processes

What are some of the setbacks to scientists warning the public about a possible geohazard?

The primary setbacks stem from scientific uncertainty, communication barriers, and the economic and social consequences of issuing alarms

How did our Universe, Solar System, and Earth form? What are their Approximate ages?

The Universe

• The Big Bang started the Universe about 13.8 billion years ago.

• All matter, energy, space, and time expanded rapidly from a single, extremely hot and dense point.

• As the Universe expanded, it cooled, allowing basic atoms to form and gravity to eventually group them into stars and galaxies.

2. The Solar System

• The Solar System began about 4.6 billion years ago.

• A massive, rotating cloud of interstellar gas and dust—the solar nebula—collapsed under its own gravity.

• Most of the material pulled toward the center to create our Sun.

3. Earth

• Leftover gas and dust spinning around the young Sun clumped together into larger masses through a process called accretion.

• Gravity pulled these smaller space rocks and planetesimals together to form Earth about 4.54 billion years ago.

• Early Earth was hot and molten, eventually cooling to form a solid crust, oceans, and an atmosphere

Be able to explain the Earth’s Solar Energy distribution.

Equator: Gets the most direct sunlight, so it receives more solar energy and is generally warmer.

• Poles: Get sunlight at a lower angle, so the same energy is spread over a larger area. They receive less energy and are colder.

• Middle latitudes: Get an amount between the equator and poles.

• Earth’s tilt: As Earth orbits the Sun, the tilt changes how much sunlight different areas receive, creating seasons.

Easy way to remember:

Equator = concentrated sunlight = more energy ☀
Poles = spread-out sunlight = less energy ❄

What are the divisions of the geologic timescale?

Back: Eons → Eras → Periods → Epochs

🧠 Memory trick: Every Earth Period Ends — Eon → Era → Period → Epoch.

Where does Earth’s Magnetic Field originate?

From the movement of molten iron and nickel in Earth’s outer core.

Are some hazards more deadly than others?

Yes. Some hazards cause far more deaths than others.Because they vary in strength, frequency, exposure, and how prepared people are.

What is the magnitude -frequency concept?

The bigger an event is, the less often it usually happens.

For example, small earthquakes happen frequently, while very large earthquakes happen much less often

Can the consequences of hazards be minimized?

Yes. Through preparation, early warnings, planning, and stronger buildings.

Natural hazard

A natural event that can potentially harm people or property.

Disaster

A hazardous event that causes major damage and disrupts society.

Catastrophe

An extremely large disaster causing widespread, severe damage.

mitigation

Actions taken to reduce the damage caused by hazards.

Geologic cycle

The continuous processes that create, change, and destroy rocks and Earth materials.

Tectonic cycle

The movement and recycling of Earth's crust caused by plate tectonics

Biogeochemical cycles

The movement of elements like carbon and nitrogen through Earth’s systems

hydrologic cycle

The continuous movement of water through Earth's surface, atmosphere, and underground.

Prediction

A statement about when and where an event is expected to happen.

Magnitude

A measurement of the size or strength of an event.

Frequency

How often an event occurs.

Warning

A notification that a hazardous event is happening or about to happen.

Forecast

An estimate of when, where, or how an event may occur.

Land use planning

Deciding where buildings and development should occur to reduce hazard risks.

Equator

An imaginary line around Earth at 0° latitude that divides the Northern and Southern Hemispheres.

Risk versus acceptable risk

Risk is the possibility of harm or loss from a hazard and acceptable. Wrist is the level of risk people or society are willing to tolerate.

Dissolution

The process of a substance dissolving into a liquid

Scientific method

A process of asking questions, testing ideas, and using evidence to reach conclusions

Precursor events

Smaller events or changes that may happen before a larger event.

Magneto sphere

The region around Earth controlled by Earth's magnetic field.

Solar wind

A stream of charged particles constantly flowing from the Sun.

Carrying capacity

The largest population an environment can sustainably support.

Exponential growth

Population growth that increases faster and faster when resources are abundant

Atmosphere

The layer of gases surrounding Earth.

Biosphere

All parts of Earth where life exists

Hydrosphere

All of Earth's water, including oceans, rivers, ice, and groundwater.

Geologic process

Natural processes that shape Earth's surface and interior

insolation

Incoming solar radiation received by Earth.

Nebular hypothesis

The idea that our solar system formed from a large cloud of gas and dust.

Chemical differentiation

The separation of materials inside Earth based on their density and chemical properties.

Birth rates

The number of births in a population during a given period.

Solar energy effects

Principles of superposition

In undisturbed rock layers, the oldest layer is on the bottom and youngest is on top.

Principle of Uniformitarianism

The idea that the same natural processes operating today operated in the past

World population

The total number of people living on Earth.

Principle of strata continuity

Rock layers originally extend sideways until they thin out or meet a barrier.

Principle of crosscutting relationship

A feature that cuts through another rock is younger than the rock it cuts.

Principle of original horizontality

Sedimentary layers are originally deposited in nearly horizontal layers.

Law of faunal succession

Fossil organisms occur in a recognizable, predictable order through rock layers.

Nicolaus Steno

Developed important principles of relative dating, including superposition and original horizontality.

William Smith

Used fossils to identify and correlate rock layers; developed the idea of faunal succession.

Charles Lyell

Expanded and popularized uniformitarianism and argued that geological processes operate over long periods of time.

James Hutton

Proposed that Earth is extremely old and shaped by slow, continuous processes.

Fossils (covered PPT 2/12)

Preserved remains, impressions, or traces of ancient organisms.

Petrified Trees

Trees whose original material has been replaced by minerals, turning them into stone.

Stromatolites

Layered structures formed by microorganisms, especially ancient cyanobacteria.

Relative Age Dating

Determining whether rocks or events are older or younger than others without finding an exact age

Formation of Universe ~14.6 bya

The universe began about 14.6 billion years ago, according to the age used in your course.

Formation of our Sun ~4. 6 bya

The Sun formed about 4.6 billion years ago from a collapsing cloud of gas and dust.

What are the milankovitch cycles?

Changes in Earth's orbit and orientation affecting solar radiation.

What do Milankovitch Cycles help explain?

Glacial advance and retreat over earths history

What is eccentricity

Changes in the shape of earths orbit around the sun

What is obliquity

Changes in earths axial tilt

What is precession

The gradual wobble or change in earths rotational axis

Which season is especially important for glacial changes

Summer especially in high latitude

What are o16 and o18

2 types of oxygen used to study past climate

What are foraminifera

Tiny marine organisms whose shells preserve climate evidence

What is the difference between an asteroid and meteoroid

Astroids are larger space rocks and meteoroids are smaller

What is a comet

An icy object that orbits the sun and can form a tail

What is a meteor

The streak of light from a space rock entering an atmosphere

What is a meteorite

A space rock that survives passage through the atmosphere and reaches earth

What is an impact crater

A depression formed when an extraterrestrial object hits earth

What is an airburst

An explosion of an space object in the atmosphere before impact

What is breccia

Rock made of broken angular fragments cemented together

What is the k-t boundary

A rock layer marking the end Cretaceous mass extinction

Why is iridium important to the impact hypothesis

An unusual iridium layer supports an extraterrestrial impact

What was the Tunguska event

A major atmospheric airburst over Siberia in 1908

What can asteroids impacts cause besides craters

Airburst, shock waves, fires,tsunamis, and climate change

What are mass extinctions

Periods when many species become extinct in a short time

What is one major cause proposed for mass extinctions

Large asteroids or comet impacts