Notes, summaries, assignments, exams, and problems for Geology

The Seismic Method

An indirect method of study that looks at the variations in the propagation speed of seismic waves as they travel through different materials inside the geosphere.

What are Seismic Waves?

Vibrations generated inside the Earth at the point where an earthquake takes place. They propagate in all directions, and the more rigid the material they pass through, the more quickly they travel. There are three types:

• P waves: Cause the material to vibrate, alternating between compression and dilation. These waves propagate through solids and liquids.
• S waves: Cause the material to oscillate perpendicular to the direction of propagation. They are slower and cannot travel through liquids.
• Surface waves: Generated when P and S waves reach the

... Continue reading "Earth's Interior Structure: A Seismic and Geochemical Perspective" »

Key Concepts in Geology

(exam3)1:superposition=the oldest on the bottom, youngest on top/2:original horizontality=sedimentary layers/lava flows are deposited as flat layers/3:lateral continuity=rocks extend in all directions until they reach the edge of a basin or pinch out/4:cross-cutting=faults and fractures are younger than the rocks they cut through/5:unconformities=missing time/6:inclusions=chunks of weathered rock are older than the rock they are contained in/7:continental drift=Alfred Wegener/8:Alfred Wegener=Pangaea/9:not a major tectonic plate/Juan de Fuca Plate/10: lithosphere=composed of crust and upper mantle/11:continental crust=composed of granite and basalt/12:transform boundary=one colliding plate will be forced because of difference... Continue reading "Understanding Geology: Key Concepts and Terms" »

Mooring Line

A rope or wire used to make a ship fast to a quayside.

Traffic Separation Scheme

A routing measure aimed at separating opposing streams of traffic by appropriate means and establishing traffic lanes.

Liferaft

A small, inflatable watercraft without a motor, carried for emergency evacuation in the event of a disaster aboard a ship.

Immersion Suit

A special type of waterproof dry suit that protects the wearer from hypothermia from immersion in cold water after abandoning a sinking or capsized vessel, especially in the open ocean.

Lifeboat

A small, rigid watercraft fitted with a motor, carried for emergency evacuation in the event of a disaster aboard a ship.

Island

A land mass, especially one smaller than a continent, entirely surrounded by... Continue reading "Essential Maritime Terms: Safety and Navigation Rules" »

Igneous:form.Melting Magma(surface),Lava:magma extruded to surface,Granite&Basalt. Intrusive(below surf pluton-100km2batholith)Extrusive(above surf)90% crust,Jointing-parallel cracks,Exfoliation-peel-off.(Ex.Dome)

Sedimentary:compounds settling(weathering,compaction,cementation-Limestone&SandStone)strata=layers,Clastic sediments=transported water,wind,ice,grav.Chemical sediments=minerals dissolved solution.

Metamorphic:altering processes(heat&pressure)Harder,compression, crushed,cooked,shear and stress.Ex:Marble,Gneiss,slate.Foliated=texture distinct wavy lines of min. Plate tectonics:adrift cause convection currents in upper mantle 6cm/y,Pangae=allEarth-225mil y Triassic Period,Tectonic=building-constr.Sea-floor-spreading-64miKm... Continue reading "Comparing the surface wind to the 3000ft wind:" »

Essential Concepts in Earth's Atmosphere and Oceans

Thermodynamics and Heat Transfer

Temperature

The average kinetic energy of molecules or atoms in a material, representing the kinetic energy of a substance.

Heat

The total energy of molecules or atoms in a material. You can have a large amount of heat but low temperatures, or high temperatures but little heat (depending on the mass of the substance).

Latent Heat

The amount of heat required to completely change a quantity of water from phase A to phase B with no corresponding change in temperature. The term “Latent” means “hidden.”

Latent Heat vs. Sensible Heat

Latent and sensible heat are types of energy released or absorbed in the atmosphere.

• Latent Heat: Related to changes in phase (e.

... Continue reading "Essential Concepts in Meteorology and Oceanography" »

Planetary Origins and Earth's Structure

1.1 The Formation of Earth

Our solar system was formed from a solar nebula, or cloud of gas and dust, that collapsed and condensed about 4.56 billion years ago.

Most of this matter compacted together to form the Sun, while the remainder formed planets, asteroids, and smaller bodies.

Terrestrial vs. Jovian Planets

The outer planets—Jupiter, Saturn, Uranus, and Neptune—condensed at cold temperatures and are made mostly of hydrogen and helium. In contrast, the terrestrial planets (Mercury, Venus, Earth, and Mars), formed closer to the Sun, contain large amounts of iron, silicates (silicon and oxygen), magnesium, and other heavier elements that condense at high temperatures.

About 4 billion years ago, conditions... Continue reading "Planetary Formation, Geologic Time, and Earth's Core Composition" »

1. Non-Ferrous Metals and Their Alloys

1.1 General Non-Ferrous Metals

• Medium Melting Temperature: Cu, Ni
• Low Melting Temperature: Zn, Cd

1.2 Light Metals

• Medium Melting Temperature: Al, Mg, Be
• Low Melting Temperature: Li, Na

1.3 Noble (Precious) Metals

• Medium Melting Temperature: Ag, Au
• High Melting Temperature: Ru

1.4 High Melting Temperature Metals

• BCC Lattice: W, Ta
• HCP Lattice: Ti, Zr

1.5 Rare Earth Metals

• Trace Metals: Sc, Y, La
• Lanthanides: Ce, Pr

1.6 Radioactive Metals, Transuranides, and Transactinides

• Naturally Occurring Radioactive Metals: Po, Fr
• Transuranides and Actinides: Np, Pu
• Transactinides and Superactinides: Rf, Db

Metal Purity Levels:

• Raw Metal: 3-5% of impurities
• Technically Pure Metal: Up to 1% of impurities (fluxing)
• Electrolytically Refined

... Continue reading "Non-Ferrous Metals and Their Alloys: An In-Depth Guide" »

Proctor Compaction Test

1. Obtain air-dry soil on which the compaction test is to be conducted.

2. Sieve the soil.

3. Add enough water.

4. Determine the weight of the Proctor mold + base plate.

5. Attach the extension to the top of the mold.

6. Pour the moist soil into the mold in three equal layers.

7. Remove the top attachment from the mold.

8. Using a straight edge, trim the excess soil above the mold.

9. Determine the weight of the mold + base plate +- compacted moist soil in the mold, W2 (lb).

10. Remove the base plate from the mold. Using a jack, extrude the compacted soil cylinder from the mold.

11. Take a moisture can and determine its mass, W3 (g).

12. From the moist soil extruded in Step 10, collect a moisture sample in the moisture can (Step... Continue reading "Proctor Compaction Test Procedure and Equipment" »

... Continue reading "Material Science: Strengthening Mechanisms and Fracture" »

Understanding Water Pollution

Water pollution is any chemical, physical, or biological change in water quality that has a damaging effect on anything living that consumes that water. When humans drink contaminated water, they often have health problems. Water contamination can also make it unsuitable for its intended use.

Common Types of Water Pollutants

There are several kinds of water pollutants. The first of these are disease-causing agents. These include bacteria, viruses, protozoa, and parasitic worms that are incorporated from sewage systems and raw sewage.

Oxygen-Consuming Agents

A second category of water pollutants are oxygen-consuming agents; these are residues that can be decomposed by oxygen-consuming bacteria. When the bacterial populations... Continue reading "Impacts and Causes of Water Contamination" »