Oceanography Chapter 1,2,3

Comparison of Earth with Venus and Mars (ch.1)

How do temperatures and atmospheres differ?

Earth: mild temp, rich in nitrogen and oxygen atmosphere

Venus: Extremley hot (hottest planet) due to its thick carbon dioxide atmosphere that traps heat

Mars: Much colder than earth, thin atmosphere, made of carbon dioxide (can’t hold much heat)

Comparison of Earth with Venus and Mars (ch.1)

Why did they develop differently?

Distance from sun, water and CO2 properties (greenhouse effect)

Earth has the right conditions to keep liquid water and a stable climate.

Venus’s thick atmosphere trapped too much heat.

Mars lost its atmosphere bc it’s smaller and further from the sun, so it couldn’t stay warm.

Comparison of Earth with Venus and Mars (ch.1)

What are the two main groups of planets in our solar system?

Terrestrial/Inner Planets: Mercury, Venus, Earth, and Mars

Gas Giants/Outer Planets: Jupiter, Saturn, Uranus, and Neptune

Which are the four spheres on Earth and what are their characteristics? (ch.1)

Geosphere: Earth’s solid parts, density layered

Hydrosphere: All of Earth’s water

Atmosphere: Mixture or nitrogen, oxygen, carbon dioxide, argon, and other gases.

Biosphere: All life on earth, interacting with water, land, and air

What is density layering, which are the major layers of the geosphere? (ch.1)

Density Layering: Earth is made of layers that have different densities, with heavier layers inside and lighter layers outside.

• Core: Dense metallic core (outer core liquid, inner core solid, ~6000°C, mainly nickel and iron)

• Mantle: Less dense rocky layer, partly solid, partly plastic-like and slowly flowing

• Crust: Least dense surface layer with varied materials like granite, sandstone, and limestone

What percentage of water on Earth is contained in the oceans? (ch.1)

Approximately 97% of Earth’s water is contained in the oceans.

What percentage of Earth’s surface is covered by the oceans? (ch.1)

Oceans cover about 71% of Earth’s surface.

Gradualism and Uniformitarianism (ch.1)

Hutton-slow change across long time (observing how the slow, consistent erosion of the Colorado River carved the Grand Canyon over millions of years)

Catastrophism (ch.1)

Whewell -rapid events in short times (floods, earthquakes, volcanoes)

Threshold and Feedback Effects (ch.1)

• Threshold: A tipping point causing sudden change.

  • Example: Arctic ice melts slowly, but after losing enough ice (passing the threshold), it melts rapidly.

• Feedback: When the system affects itself.

  • Positive feedback: Speeds up change.

    • Example: Melting ice lowers reflectivity, so Earth warms more, melting more ice. or Venusian Climate

  • Negative feedback: Slows change.

    • Example: Cooling causes more ice, increasing reflectivity and slowing warming.

Minerals are: (ch.2)

Naturally occuring, inorganic (no C-H bonds), solid, have a definite chemical composition, crystalline structure.

What are the most important properties of a mineral? (ch.2)

Chemical Composition and Crystalline Structures

Eight most abundant element in Earth’s crust (ch.2)

• Oxygen (O) – 46.60%

• Silicon (Si) – 27.72%

• Aluminum (Al) – 8.13%

• Iron (Fe) – 5.00%

• Calcium (Ca) – 3.63%

• Sodium (Na) – 2.83%

• Potassium (K) – 2.59%

• Magnesium (Mg) – 2.09%

What are the charges and locations of atomic particles? (ch.2)

• Protons: Positive (+), in the nucleus

• Neutrons: Neutral (0), in the nucleus

• Electrons: Negative (−), orbit the nucleus

What is the difference between ionic and covalent bonds? (ch.2)

Ionic Bonds:Electrons are transferred (ex naCi-halite)

Covalent Bonds: Electrons are shared (ex. Diamonds)

What are the chemical formulas/compositions of quartz and halite? (ch.2)

Quartz: SiO₂

Halite: NaCl

What is a crystalline structure? (definition, unit cell, crystal shape) (ch.2)

A regular, repeating arrangement of atoms in a mineral.

The unit cell is the smallest repeating atomic pattern that makes up the structure.

Crystal Shape is the outside form that shows how the atoms are arranged inside

Physical Properties of Minerals (ch.2)

Habit

General crystal shape or appearance (e.g., prismatic quartz)

Physical Properties of Minerals (ch.2)

Cleavage

The splitting of a mineral along planar surfaces (e.g., muscovite, calcite)

Physical Properties of Minerals (ch.2)

Fracture

Irregular break (e.g., smoky quartz)

Physical Properties of Minerals (ch.2)

Hardness (Moh’s scale)

Resistance to scratching [1.Talc 2.Gypsum (fingernail), 3.Calcite (copper penny), 4.Fluorite, 5.Apatite (knife blade, window glass), 6.OrthoClase(steel file), 7.Quartz, 8.Topaz, 9.Corondum, 10.Diamond]

Physical Properties of Minerals (ch.2)

Specific Gravity

Density Relative to Water

Physical Properties of Minerals (ch.2)

Streak

Color of mineral in powdered form (e.g., hematite = reddish streak)

Physical Properties of Minerals (ch.2)

Luster

How mineral reflects light

• Metallic (e.g., pyrite)

• Non-metallic (glassy, earthy, etc.)

What is the most abundant class of Minerals? (ch.2)

Silicates, making up about 92% of Earth’s crust.

What is the basic unit of silicate minerals? (Ch.2)

The silicon-oxygen tetrahedron (SiO₄).

What are the most common silicate minerals? (ch.2)

-Feldspar group (51%)

-Quartz (12%)

What is an example of a carbonate mineral and its composition? (ch.2)

Calcite (CaCO3)

What are examples of native element minerals? (ch.2)

Gold (Au) and Silver (Ag)

What are some common uses of minerals? (ch.2)

• Feldspar: Ceramics, cement

• Quartz: Glass, electronics

• Muscovite: Paints, cement

• Gypsum: Plaster, wallboard

• Talc: Cosmetics

• Halite: Table salt

• Diamond: Cutting tools

Mineral Matter can be made by an organism (ch.2)

True

The silicate Tetrahedron consists of (ch.3)

One central silcon ion surrounded by four oxygen ions

What are the three types of rocks? (ch.3)

Igneous, Sedimentary, Metamorphic

What is the rock cycle? (ch.3)

The continuous process of rock formation and transformation between igneous, sedimentary, and metamorphic rocks

Igenous Rock (ch.3)

What is their source?

• Formed from magma (molten rock beneath Earth's surface).

• If magma reaches the surface, it becomes lava.

Igenous Rock (ch.3)

What is the difference between intrusive (= plutonic) and extrusive (= volcanic) rocks?

• Intrusive (plutonic) rocks:

  • Formed underground from magma; course-grained with large circles (≥1 mm)

  • Example: Granite

• Extrusive (volcanic) rocks:

  Volcanic rocks formed from lava at the surface; fine-grained with small crystals

  • Examples: Basalt, Obsidian, Porphyry

Igenous Rock (ch.3)

How are igneous rocks named and identified?

Based on texture (grain size) and composition (minerals present).

Igenous Rock (ch.3)

Examples for intrusive/extrusive rock pairs, their approximate composition:

• Granite (intrusive) & Rhyolite (extrusive) – felsic (high silica)

• Gabbro (intrusive) & Basalt (extrusive) – mafic (low silica)

• Diorite (intrusive) & Andesite (extrusive)

• Peridotite (ultramafic) & Komatiite (rare, ultramafic)

Igenous Rock (ch.3)

What is obsidian?

• A volcanic glass

• Forms when lava cools extremely fast

• Has no crystal structure

Sedimentary Rocks (ch.3)

What are the four types of sedimentary rocks?

Clastic, Organic, Chemical, BioClastic

Sedimentary Rocks (ch.3)

What are Clastic Rocks made of, how are they formed?

Made of: Weathered rock particles (gravel, sand, silt, or clay)

Formed: Deposition of sediments → Compaction under pressure → Lithification (turning into rock)

Examples: Conglomerate, Sandstone, Shale, Siltstone, Mudstone

Sedimentary Rocks (ch.3)

Sedimentary Structures: What is bedding (stratification)?

Horizontal layers formed during sediment deposition

Sedimentary Rocks (ch.3)

Sedimentary Structures: What is cross-bedding?

Small layers at an angle to main bedding, caused by wind or water

Sedimentary Rocks (ch.3)

Sedimentary Structures: What do ripple marks indicate?

Water or wave movement over sediment

Sedimentary Rocks (ch.3)

Sedimentary Structures:How do mud cracks form?

From drying and cracking of muddy sediment in shallow, intermittently dry environments

Sedimentary Rocks (ch.3)

Sedimentary Structures: What do raindrop imprints tell us?

That sediment was exposed to the atmosphere and rain between deposition events

Metamorphic Rocks (ch.3)

What causes metamorphism?

Heat, pressure, and/or chemical changes from hot fluids

Metamorphic Rocks (ch.3)

Does the rock melt during metamorphism?

No, it remains solid

Metamorphic Rocks (ch.3)

What is metamorphic grade?

The intensity of metamorphism (low to high), depending on temperature and pressure

Metamorphic Rocks (ch.3)

What types of changes occur during metamorphism?

Textural and mineralogical changes

Metamorphic Rocks (ch.3)

What is an example of a textural change?

Limestone → Marble (both are calcite but have different textures)

Metamorphic Rocks (ch.3)

What causes foliation in metamorphic rocks?

Growth and alignment of minerals like mica under tectonic pressure

Metamorphic Rocks (ch.3)

Example of mineralogical and textural change in metamorphism?

Shale → Gneiss

Metamorphic Rocks (ch.3)

What is contact metamorphism?

Caused by heat from nearby magma intrusion

Metamorphic Rocks (ch.3)

What is burial metamorphism?

Caused by pressure from overlying sediments

Metamorphic Rocks (ch.3)

What is regional (dynamothermal) metamorphism?

Caused by widespread heat and pressure from plate motion

Metamorphic Rocks (ch.3)

What is hydrothermal metamorphism?

Caused by chemical alteration from hot fluids, often forming ores (Au, Ag, Cu, Zn)

Metamorphic Rocks (ch.3)

—- — occurs when hot magma intrudes cooler rock of any type

Contact Metamorphism