Geography 1000 - Test 1

Sep 9th - Oct 1st

What are the 3 big questions that geographical studies aim to answer?

Where things happen, why they happen, and how they change through time

Describe human geography, physical geography and an integrated approach

Human Geography: Human systems, cultures, economies, planning and society

Integrated: A multidisciplinary approach that combines both physical and human human geography. Many questions sit in between these fields.

Physical Geography: Earth systems, climate, landforms, water, and ecosystems

What is the three step process of separating observation from explanation?

1. Observation - what do you see?

2. Question - Why is it there? What is the patter? Why now?

3. What possible explanation could produce this pattern?

What is the scientific method and what is the process at each step?

The scientific method is an organized process for building and testing explanations. The process is iterative, meaning it changes as evidence supports/weakens an explanation.

1.Observe the pattern

2.Ask a question

3.Hypothesize - this explanation must be testable and is only tentative

4. Test/Measure - Collect evidence in the lab or field

5. Evaluate - Does the evidence support or weaken my hypothesis?

6. Revise/Share - Improve, share, peer review

What is the challenge with evaluating natural systems?

Natural systems are complex and contain many variables. We must simplify systems because we cannot observe all of the data, and therefore must make assumptions about what data to include. What are key components? What is the scale? What is the time scale? What assumptions are being made?

What is the benefit to system thinking?

• Helps to establish stronger hypotheses

• Helps us choose a boundary, main components, inputs and outputs, flow, and links in feedback

• Simplifies data to allow for connections to be made and narrow down the questions that need to be asked

What is a system?

A set of connected parts that can be studied as a whole

What are the parts that make up a system?

• Boundary

  • What is included and excluded?

• Components

  • What are the parts of the system?

• Storage

  • What matter or energy is being stored temporarily?

  • Matter: occupies physical space

  • Energy: the capacity to do work or change

• Inputs

  • What comes into the system?

• Outputs

  • What leaves the system?

• Processes

  • What actions transform the system?

What is an open system?

A system where energy and matter cross the boundary

Examples: Watersheds, forests, glaciers, and storms

What is a closed system?

A system where matter is mostly contained within the boundary. This is rare/impossible in nature. Earth is nearly closed for matter but open for energy.

True or false: Storage changes when inputs and outputs are not balanced

True

True or false: An equilibrium stays constant and does not fluctuate

False. An equilibrium does not always mean nothing changes. Equilibrium systems can fluctuate and maintain its overall character.

Define steady-state equilibrium

Inputs and outputs are approximately balanced

Storage fluctuates around an average

Define dynamic equilibrium

The system continues to function but trends or fluctuations change through time.

Define threshold

A critical level of change beyond which the system can no longer maintain its previous state

What happens after a threshold is crossed?

The system may reorganize rapidly toward a new equilibrium state

When is a threshold crossed?

When the system can no longer maintain its previous behavior or form

What is resilience in a system?

A systems ability to recover from disturbance; how much change a system can absorb before changing,

What is a stable state in a system?

The system can withstand disturbances and remains at a relatively constant/ unchanged state.

What is a positive feedback loop?

A system amplifies a certain form of change

There is an initial change, the system responds, and the response causes the initial change to perpetuate or get stronger

What is a negative feedback loop?

A system dampens a certain form of change

There is an initial change, the system responds, and the response causes the initial change to be reduced or stop

How are models useful when interpreting systems?

Models make complexity manageable. Help to identify key components, test explanations, compare scenarios, communicate ideas, etc.

What is the flaw with every kind of model?

Models are not reality. They choose what data to include/exclude and what to simplify/ignore. The best model is one that answers a specific question rather than represent everything

What are the 3 common types of models

1. conceptual

2. Physical

3. Numerical

What is a conceptual model?

A diagram or explanation of components and relationships

What is a physical model?

A scaled or material representation

What is a numerical model?

Equations or data used to simulate or predict behavior

What is a map?

A map is a simplified representation of selected features and relationships in space. A map is not the world, It is a representation made for a purpose.

What are the set of choices made in a map?

1. Extent - How much of the world is in the frame?

2. Scale - How much detail is being represented?

3. Projection - How is the curvature of the earth translated into 2D?

4. Data - What information is included?

5. Symbols - How is the information drawn?

What is extent?

The geographic area covered by a map. A broad extent shows global context and large spatial patterns. Local extent shows site-level relationships and detail

What is scale?

Scale is how much detail is represented. Scale links distance on the map to distance in the real world.

A small scale = a broad view with less local detail

A large scale = site level view with more details visible

How are scale and extent different?

Extent = how much geographic area is included World? Canada? Southern Alberta? Lethbridge? Scale = how much spatial detail is represented Can we see individual streets, buildings, rivers, or only broad regions?

What is projection?

How a curved surface is transferred into 2D. Projections can distort area, shape, distance and direction.

What is the Mercator Projection?

• Conformal map

• preserves local angles and shapes

• exaggerates areas towards the poles

• Used for navigation because the constant compass bearings plot as straight lines

What is the Gall- Peters Projection?

• Also known as equal area

• Preserves relative area, shapes are stretched to do so.

What is data (on a map)?

• Maps select important data layers to match the question being asked.

• The same place can be mapped with different data: transport, land cover, smoke, elevation, ownership, risk, population, and more.

What are symbols? ( on a map?)

Symbols translate data into visual meaning.

Point symbols - specific locations

Line symbols - roads, rivers, contours

Area symbols - lakes, forests, land cover

Visual hierarchy - colour, size, and line weight

Cartographic choice: Changing symbols changes what readers notice first

What are geographic coordinates?

Latitude + longitude describe angular position on the globe.

What are projected coordinates?

A flat grid such as UTM describes x–y position, usually in metres.

What does latitude measure?

The angular distance from the equator (horizontal)

What is the latitude of the equator?

0 degrees

What is the latitude of the poles? (North and South)

90 degrees North

90 degrees South

What does longitude measure?

The angular distance from the Prime Meridian (vertical)

Where is the Prime Meridian?

0 degrees

Runs through Greenwich, England

Does N/S reresent latitude or longitude?

Latitude

Does E/W represent latitude or longitude?

Longitude

What is the difference between geographic coordinates and projected coordinates?

Geographic coordinates:

• Latitude + longitude

• angular position on a globe

• useful for sharing locations

• not ideal for measuring local distances

• Uses angles

Projected coordinates

• UTM Easting + Northing

• x–y position on a flat grid

• measured in metres

• convenient for distance, area, and field

How do you read UTM coordinates?

• Usually written as a zone + easting + northing

• Each zone is a north-south section with 6 degrees of longitude

• Read to the right → and then up ↑

• Measured in metres

What is GNSS?

Global Navigation Satellite Systems

A receiver estimates its distance from several satellites and solves for its location

How do satellites determine position?

Trilateration - Distances are used to solve the receiver position

Need at least 4 satellites - Need to solve 3D position and clock

What is the difference between GPS and GNSS?

GPS is only one part of GNSS. GPS is receivers in the United States, but there are different names in different countries. Your phone may combine signals from multiple.

What are the best conditions for GNSS?

• Open Sky

• Many visible satellites

• Good satellite geometry

• High quality receiver

• Correction services

What are the worst conditions for GNSS?

• Dense forests

• Steep mountain walls

• Urban canyons

• Reflected signals (multi-path)

• Poor satellite visibility

What is solar radiation?

Energy produced by nuclear fusion in the sun and emitted into space as electromagnetic radiation

How is solar energy emitted?

• Fusion in the core

  • Hydrogen nuclei combine with helium

  • Small portion of mass converted into energy

• Energy moves outward

  • Energy is transferred through the sun towards its surface

• Energy emits radiation

  • The sun emits energy as electromagnetic wavelengths

What is radiation?

The energy that travels through space as electromagnetic waves and photons

What is wavelength?

The distance between successive wave peaks

Why does wavelength matter?

Different wavelengths carry different amounts of energy and interact with matter in different ways.

Short wavelength=High Energy

Long wavelength=low energy

True or false: All objects warmer than absolute zero emit radiation

True

Describe the progression of the electromagnetic spectrum from shortest wavelength to longest wavelength

Gamma rays, X-Rays, Ultra Violet, Visible light, (Near, shortwave and middle) infrared, microwave, radio waves

What temperature of objects emit shorter wavelengths?

Hotter objects emit shorter wavelengths.

The sun mostly emits shortwave radiation in the form of visible light, ultra-violet and infrared.

What kind of wavelengths does the earth emit?

Mostly longwave radiation in the form of thermal infrared

What does the term insolation mean?

Incoming solar radiation

How does sun angle control surface sunlight?

Direct sun rays (head on) → energy is concentrated

Oblique sun rays (slanted) -→ energy is spread out

A lower sun angle means a larger area is illuminated but there is lower energy concentration

What are the 3 ways the atmosphere filters incoming solar radiation?

Reflected - Clouds, aerosols, bright surfaces, etc. reflect shortwave radiation back into space

Scattered - Energy “bounces” off of molecules and particles and redirects radiation in multiple directions

Absorbed - Atmospheric gases, clouds, surface, etc. absorb energy and warm

What is the subsolar point?

Where the sun is directly overhead at solar noon

What is the equinox?

Day length is = to night length

Earth’s tilt is perpendicular to the sun (straight)

What is the June solstice?

Earth is tilted towards the sun → 23.5 degrees North

Longest day of the year (Northern Hemisphere)

What is the December solstice?

Earth is tilted away from the sun → 23.5 degrees South

Longest night of the year (Northern Hemisphere)

What is net radiation?

Net radiation = energy inputs - energy outputs

If the net radiation is positive, the surface gains energy

if the net radiation is negative, the surface loses energy

What is albedo?

The fraction of incoming sunlight reflected by a surface

What is a high albedo?

A bright surface that reflects more energy

Snow, Ice, bright clouds, sand, etc.

What is a low albedo?

A dark surface that absorbs more energy

Water, wet soil, asphalt, dense forest

Describe how energy surplus and deficit drive circulation

Low latitudes gain more energy than they lose (positive net energy)

High latitudes lose more energy than they gain (negative net energy)

Atmosphere and ocean move energy from surplus area towards deficit regions

What are the 3 factors that explain seasonal change?

Tilt, revolution, solar angle + day length

True or false: Seasons are caused by the earth being closer to the sun in summer and farther away in winter

False

Describe Earth’s orbit

• Slightly elliptical

• Earth-Sun distance changes but not enough to explain the seasons

What is aphelion?

• On July 4th

• Earth is the farthest away from the Sun

• During northern hemisphere summer

What is perihelion?

• On January 3rd

• Earth is closest to the Sun

• During northern hemisphere winter

Describe the earth’s axis

• 23.5 degree tilt

• Half of the year, the Northern Hemisphere tilts toward the Sun (more energy)

• Half of the year, it tilts away (less energy)

• The Southern Hemisphere experiences the opposite pattern

What is solar altitude?

The angle between the sun and the horizon

High sun altitude = more direct rays = more concentrated energy

Low sun altitude =less direct rays = less concentrated

Describe how daylength changes

• Daylength changes more strongly towards the poles

• Summer =longer days= more time to receive energy

• Winter = shorter days = less time to receive energy

Why is summer warmer than winter?

Summer has a higher solar angle, longer day length, and more incoming energy throughout the day

Winter has a lower solar angle, shorter day length, and less incoming energy throughout the day

Describe low latitudes

Sun angle stays relatively high. Day length changes less. Seasons are often defined more by rainfall than temperature

Describe mid-latitudes

Clear contrasts in temperature and day length. The four familiar seasons are most recognizable here.

Describe high latitudes

Extreme day-length differences. Very low winter Sun angles and long dark seasons. Strong seasonal contrasts

What is the atmosphere and why is it important?

The atmosphere is a thin layer of gases that surround the earth.

The atmosphere:

• Directly supports the processes of life

• Protects against harmful solar radiation

• Helps to regulate the climate

• Makes weather possible

Describe the first stage as Earth’s atmosphere before it developed

• Early earth was extremely hot and inhabitable

• Had no atmosphere, oxygen-rich air, or ozone layer

Describe the first stage as Earth’s atmosphere developed

• Earth cooled slowly

• Gases like hydrogen and helium spewed from volcanoes

• Contained water vapour, carbon dioxide, nitrogen, Sulphur, and other trace gases

• Atmosphere formed through outgassing and comets/asteroids

Describe the second stage as Earth’s atmosphere slowly developed

• The earth cooled resulting in condensation, clouds, and rain

• The atmosphere thinned

• Water vapour condensed into oceans

• Nitrogen levels increased

• Still no oxygen in atmosphere

Describe the third stage as Earth’s atmosphere developed

• Aquatic life in the ocean

• Cyanobacteria make oxygen from CO2

• Oxygen slowly accumulates in the atmosphere

• We can see this through geological evidence of oxygen reacting with iron in rocks, causing it to oxidize and leave red/orange bands

Describe the final stage of Earth’s atmosphere as it developed

• Photosynthesis added oxygen to the atmosphere

  • Oxygen accumulated and formed the ozone layer which protects the surface from harmful UV

Describe how the atmosphere acts as a reservoir

• The atmosphere is not static, there is both input and output and things can change

What is an example of a source that acts as an input for the atmosphere?

• Human activity/cellular respiration/pollution

• Photosynthesis

• Comets/asteroids

Sources add gases to the atmosphere

Describe what a sink is in terms of Earth’s atmosphere

Sinks remove gases from the atmosphere

• Oceans/large bodies of water

• Forests/large bodies of trees

Describe how atmospheric pressure is not evenly distributed

Air is constantly moving.

Thinner areas of air = less air = less weight / pressure

Thicker areas of air = more air = more weight /pressure

What is atmospheric pressure influenced by?

• Air movement and particle collision

• Mass and weight of air

• Density (number of molecules)

• Gravitational pull towards Earth’s center

What is the relationship between pressure and density?

High pressure = high density

low pressure = low density

Why is it more difficult to breathe at higher altitudes?

Less air, less pressure, lower density of oxygen molecules.

Describe STP and why it is important

Temp: 15 degrees C or 273.15 K

Pressure: 101.325 kPa

Density: 1.23 kg m^-3

Real conditions constantly change, gives standard baseline for comparison