Untitled Flashcards Set

Continental Coastlines

The shapes of certain continents’ coasts, such as South America and Africa, which fit together like a puzzle; evidence supporting plate tectonics.

Fossil Evidence

The presence of identical fossils across separate continents, supporting the theory of plate tectonics.

Earthquake Distribution

The concentration of earthquakes around plate boundaries, indicating movement of tectonic plates.

Divergent Boundaries

Areas where tectonic plates move apart, resulting in the generation of new seafloor.

Mid-Ocean Ridges

Underwater mountain ranges where fresh magma rises and the crust is slightly elevated.

Subduction Zones

Regions where old seafloor is recycled as tectonic plates slip downwards, leading to earthquakes and the rise of magma.

Transform Plate Boundaries

Boundaries where two tectonic plates slide past each other, often causing earthquakes.

Layers of the Earth

The three main layers of the Earth: crust, mantle, and core.

Body Waves

Seismic waves that travel deep into the Earth, faster than surface waves.

Surface Waves

Slower seismic waves that only travel on the Earth's surface.

S-waves Reaction

S-waves are reflected when they encounter different materials.

P-waves Reaction

P-waves are refracted when they hit varying materials.

Brittle Deformation

A type of deformation that results in the formation of faults.

Ductile Deformation

A type of deformation that results in the formation of folds.

Metamorphic Rocks

Rocks formed under conditions of high temperature and pressure.

Brittle Deformation Conditions

Occurs under cold and short conditions.

Ductile Deformation Conditions

Occurs under hot and long conditions.

Millimeters in Centimeter

10 millimeters are equivalent to 1 centimeter.

Half-rate Formula

The formula for calculating half-rate is Distance divided by time (km/ma).

Total Velocity Equation

Total velocity is calculated as 1/2 rate multiplied by 2.

Plate Tectonics Premise

The Earth's surface is composed of distinct plates, supported by fossil evidence and seismic activity.

Active Plate Boundary Types

Three basic types: divergent (move apart), convergent (come together), transform (slide past each other).

Divergent Boundary Characteristics

Associated with mid-ocean ridges; lava rises from faults created by plates moving apart.

Convergent Boundary Characteristics

Involves subduction zones; leads to volcanic activity and mountain formation.

Transform Boundary Characteristics

Plates slide past each other, causing earthquakes; typically no mountains or valleys formed.

Volcanic Island Chains Orientation

Indicates the presence of a convergent plate boundary and direction of plate movement.

Map and Elevation Data

Can be used to distinguish between different plate margins.

Convection in Geology

The heating and cooling of rock, creating a cycling motion that drives tectonic plate movement.

Convection Relevance to Plate Tectonics

Convection drives the movement of tectonic plates, causing them to move apart, converge, or slide past each other.

Seafloor Features

Affected by plate tectonics; for instance, mid-ocean ridges form from divergent boundaries.

Seafloor Spreading Process

Results from counterclockwise and clockwise convection zones driving tectonic motion.

Continent Growth

Continents grow larger as magma rises to the surface; no processes shrink continental size.

Earthquake Definition

A seismic wave generated by the slipping of rock along fault boundaries.

Earthquake Sources

Includes normal faults, reverse faults, strike-slip faults, volcanic eruptions, landslides, and explosions.

Earthquake Location Relation to Plate Boundaries

Earthquakes closely relate to three types of plate boundaries, each with distinct seismic patterns.

Earthquake Depth Differentiation

Deep earthquakes occur at subduction zones, while shallower earthquakes relate to strike-slip faults.

Lithosphere vs Asthenosphere

Lithosphere is rigid and solid (crust); Asthenosphere is partially molten and weak (mantle).

Fault Types

Vertical faults (normal and reverse), and strike-slip faults (left lateral and right lateral).

Epicenter vs. Focus

The epicenter is the point on the surface above where an earthquake occurs; the focus is the actual point within the Earth.

P-wave Speed

P-waves are the fastest seismic waves; they compress particles as they propagate.

S-wave Speed

S-waves arrive second, causing a shearing motion and cannot travel through liquids.

Earth Material Influence on Shaking

More compact earth materials experience more intense shaking than loose materials.

Magnitude Scale Definition

Scale measuring the maximum S-wave amplitude of an earthquake; each level is 10 times greater.

Magnitude Relation to Energy

Energy release increases by a factor of 31.7 between each whole number of the magnitude scale.

Magnitude and Earthquake Frequency

Higher magnitudes correspond to less frequent occurrences.

Tsunami Definition

Columns of ocean waves caused by large disturbances like earthquakes.

Fault Movement Waves

Columns of waves radiate from a fault until energy dissipates or collides with a surface.

Earthquake Locations

Typically occur along fault lines, such as the New Madrid fault and San Andreas fault.

Earthquake Prediction Capabilities

Estimated timeframes for patterns of earthquakes can be studied, but precise details cannot be predicted.

Refraction Definition

When seismic waves encounter materials of different densities and bend.

P-wave Shadow Zones

Areas where P-waves do not reach due to refraction through the core.

S-wave Shadow Zones

Areas where S-waves cannot reach because they cannot pass through liquid.

Seismic Velocity Discontinuities

Indicate the transition between different layers, such as the outer liquid core.

Earth's Large Scale Structure

Comprised of multiple layers with different compositions, as revealed by seismic waves.

Stress in Geology

The amount of force applied to an area.

Strain in Geology

The reaction to stress, leading to deformations like folds or faults.

Shear Stress Effect

Causes the two sides of an object to be pulled in opposite directions.

Tensional Stress Effect

Pulls an object apart.

Compressive Stress Effect

Pushes an object together.

Elastic Strain Definition

Strain that causes little long-term damage to the object.

Ductile Strain Definition

Strain causing a rock to flow like a liquid.

Brittle Strain Definition

Strain that results in the rock cracking or breaking.

Brittle-Ductile Transition

Transition zone where rocks change from brittle to ductile deformation due to heat and pressure.

Fold Definition

A bend in rock layers resulting from ductile deformation.

Ductile Compression Reaction

Bends or folds earth materials due to stress.

Fault Definition in Geology

A fracture resulting from tectonic forces that causes movement.

Joint vs Fault

Joints are cracks without movement; faults are larger and involve movement.

Strike-slip Fault Characteristics

Horizontal movement of rocks past each other.

Dip-slip Fault Characteristics

Vertical movement of rocks.

Hanging Wall Definition

The block of rock lying above a fault.

Footwall Definition

The block of rock lying below a fault.

Anticlines Definition

Upward-folded layers of rock, shaped like an 'A'.

Synclines Definition

Downward-folded layers of rock, shaped like a 'U' or 'V'.