Fundamental Concepts

Number one environmental probelm

Population growth

• Resource depletion to accomodate for growth

Doubling time

70/growth rate

Freshwater salinization

caused by unregulated road salts, which melt into drinking water basins and lead to unhealthy water quality

Nitrogen pollution

caused by the algae and bacteria created from nitrogen and phosphorus in water, which decompose to suck up oxygen;

hypoxia

a dead zone in water with little oxygen

Residence times

the amount of time a substance (water, carbon, nutrients) remains in a reservoir/pool before relocating

Mass balance approaches

a method to analyze how a substance moves through a system by considering inputs, outputs, and internal changes

Pools

• places where water, carbon, nutrients can subside

• storage locations where matter accumulates in a system

Fluxes

the movements of materials between pools

Steady state system

inputs and outputs are balanced, meaning there is no net accumulation of depletion in the pools

Earth System Science

Studies the earth as a whole and its components through the lens that the earth is a interconnected system

Uniformitarianism

• the earth’s processes are continuous and have been so throughout history to shape our earth today

• james hutton, father of geology

• fundamental concept of earth science

Catastrophism

earth has rapid changes (asteroid) to change it

5 Spheres

Atmosphere: weather, climate, greenhouse effect

Lithosphere/geosphere: plate tectonics, minerals, rocks

Hydrosphere: water bodies (ocean, river, lake, groundwater, etc)

Anthroposphere: human activity (pollution, climate change, urbanization)

Biosphere: biodiversity and all living organisms and ecosystems

Human intervention with nitrogen cycle

1. Fertilizer

   1. Synthetic nitrogen fertilizer → extra nitrogen in soil → runoff of nutrients into water body

2. Fossil fuel combustion

   1. Burning coal, oil, and gas has contributed to pollution of atmosphere → SMOG and acid rain

Scientific method

Observation → Hypothesis → Test → Validify

• repeated one is a theory

Wegener’s Theory

Theory of Continental drift (Pangaea, rejected bc no basis - now seafloor spreading supports)

Seafloor spreading

• New oceanic crust (mafic) created at ocean ridges at divergent plates

• Other end of the plate is being destroyed bc lithosphere is sinking into subduction zone

paleomagnetism

• the study of the Earth's past magnetic field, as recorded in rocks and sediments

• evidence for plate tectonics and continental drift

• magnetic poles

Lines of evidence

• paleomagnetism

• fossil distribution

• geological fit

• seismic/volcanic activity

Harry Hess

continents and ocean floor work in tandem

liquid outer core

responsible for earth’s magnetic field

mantle

responsible for movement of tectonic plates

Divergent

seafloor created, shallow earthquakes, volcanic activity, ridges + rifts

convergent

seafloor destroyed, shallow and deep earthquakes, volcanic activity, mountains + trenches

Transform

seafloor neither created or destroyed, shallow earthquakes, oceanic crust - san andreas rift in CA

isostasy

• thicker, more buoyant crust will weigh down thinner, denser crust

• gives mountains height

• faster uplift = greater erosion = uplift, max height reached

Magnetic stripes

• symmetrical and alternating magnetic anomalies (high/low magnetism stripes) along the seafloor, usually mid atlantic ridges*

• Key piece of evidence supporting theory of plate tectonics and process of seafloor spreading

Subduction zone

where a plate subducts beneath another due to differences in density - convergent boundaries

Mid-ocean ridge

underwater mountain range formed at divergent plate boundaries where new seafloor is created

Hot spots

area of mantle where heat from deep earth rises to form a chain of volcanoes, independent of plate movements

Hot spots form igneous rocks →silica-based and dark magma

rock

aggregates of one or more minerals

classify using composition and texture

mineral

element or chemical compound that is normally crystalline

isotope

atoms of the same element with varied number of neutrons

• important because it reveals glacial patterns throughout history and can help provide evidence for climate change

atom

smallest part of a chemical element that can react or combine with another element

Covalent

1. Form when atoms share electrons (ex. diamonds)

2. Stronger than ionic

Ionic

1. Form from attraction between positively and negatively charged ions (ex. Na+Cl-)

2. More soluble → chemically active and mobile in environment

metallic bond

1. Electrons are shared by all atoms of the solid rather than the specific atoms

2. Form between metal atoms → cause ability to conduct electrical currents, malleability, form apper-thin sheets (ex. GOLD)

van der waals

1. Weak attraction between chains/sheets of ions that are bonded by stronger covalent/ionic  bonds

2. Graphite and diamond are both carbon

Sedimentary

• 75% of all rocks exposed at Earth’s surface

• Form when sediments are transported/deposited into rock

Igneous

Intrusive (large crystals)

Extrusive (small crystals)

Metamorphic

heat, pressure, chemically active fluids - solid state transformation

Law of horizontality

new sediment layers deposited horizontally

law of superposition

youngest layers on top

law of cross cutting relationships

younger rock cuts though older rock

Mineral characteristics

• Inorganic

• Crystalline structure

• Solid

• Chemical formula

• Naturally occurring

mineral properties

• Color + clarity

  • The amount of light that can pass through a mineral

• Luster

  • metallic/non-metallic (How minerals reflect light)

• Streak

  • The powdered form of a mineral

• Habit (shape)

  • Shape a mineral takes if grown unrestricted

• Cleavage + fracture

  • Cleavage: breakage along planes that cut across weak bonds

    • controlled by the mineral’s atomic structure

  • Fracture: breakage doesn’t follow a crystallographic direction, but follows an irregular surface

• hardness

Atoms

nucleus surrounded by election cloud

→smallest part in a chemical element that can take part in a chemical reaction/combine with another atom

→ important because it makes up all matter

Chemical bonding

4 types

atoms in a mineral held together by chemical bonding

-attracting forces between atoms

examples of intrusive igneous rocks

granite, diorite, gabbro, peridotite, and pegmatite

examples of extrusive igneous rocks

basalt, obsidian, pumice, rhyolite, andesite, scoria, tuff

rock cycle

worldwide rock recycling system linking internal processes (heat energy) to melts/change rocks in tectonic cycle to surface processes (solar energy)

→recycling of rock and minerals driven by internal heat

extrusive igneous textures

• Pyroclastic (debris)

• porphyritic (holes)

felsic

silica, continental

mafic

iron and magnesium, oceanic

Clastic/detrital

1. Form from broken parts of previously existing rocks

2. ex) conglomerate, shale, siltstone, sandstone

Nonclastic/chemical

1. Formed through chemical precipitation from water solutions/biological processes

2. ex) limestone, gypsum, rock salt, diatomite

Strata

bed sequences/layers in sedimentary rock

Regional metamorphism

• PRESSURE

• subduction zones

• continental collision

• convergent

contact metamorphism

• HEAT

• hotspots

• earth bbq

• convergent and divergent

sedimentary rock formation

weather, transport, deposition, lithification

agents of transport

wind, water, ice, gravity

acid mine drainage

Acidic water (low pH) flowing from mines.

1. Causes

   1. Sulfide minerals (like pyrite) exposed to air & water.

   2. Oxidation forms sulfuric acid.

   3. Acid dissolves metals from rocks into water.

volcanism

1. Heat & pressure: Alters existing rocks (metamorphism).

2. Lava flows: Form new igneous rocks (basalt, rhyolite).

3. Ash deposits: Form tuffs.

4. Hydrothermal fluids: Alter minerals & create ore deposits.

5. Gas release: Alters atmospheric chemistry, potentially affecting weathering.

Types of weathering

1. Physical: Mechanical breakdown (frost wedging, abrasion).

2. Chemical: Mineral alteration (oxidation, dissolution).

3. Biological: Plant roots, microbial activity.

Stable isotopes

do not decay. used for climate records (ice cores)

Radioactive isotopes

decay over time. used for dating rocks

Keystone species

species who provide abundance to environment (wolves in yellowstone)

communities

All populations of different species living & interacting in an area.

Ecosystems

1. Community + physical environment (biotic + abiotic).

2. Includes energy flow & nutrient cycles (water, carbon, etc.).

Climax communities

1. Stable, mature ecological community at end of succession.

2. Long-lasting unless disturbed by major event (fire, human activity).

ecological niche

"role" or "job" of a species in its ecosystem— eats, lives, behaves, interactions

riparian zone

• lands that occur along the edges of rivers, streams, lakes, and other water bodies

• helps with filtration of pollutants, protect water bodies

wetlands

• Hydrophytic + saturated soils

• Transitional ecosystems between aquatic and terrestrial areas

ocean acidification

Decrease in ocean pH due to increased CO₂ absorption.

causes of ocean acidification

1. Burning fossil fuels → More CO₂ in atmosphere → CO₂ dissolves into oceans.

environmental estrogens

1. Hormone-disrupting chemicals that mimic estrogen.

2. Sources: Plastics, pesticides, pharmaceuticals, industrial runoff → disrupt reproduction

stratification in lakes

1. Temperature differences between surface & deeper water layers.

2. Warm, less dense water on top (epilimnion); cold, denser water at bottom (hypolimnion).

algae bloom nutrient

PHOSPHORUS

• from fertilizer, sewage/wastewater/erosion in soil

NITROGEN

• fertilizer, manure, atmospheric depositon