Geology Flashcards

Flashcards covering vocabulary from geology lecture notes, including topics from the universe and solar system to the lithosphere and atmosphere.

Universe or Cosmos

Contains everything around us: galaxies, stars, planets, nebulae, supernovas, pulsars, black holes, quasars, interstellar dust

Astronomical Unit (AU)

A unit used to measure distances in our solar system, equivalent to the Earth-Sun distance. It is approximately 150 x 10^6 km.

Light-year (LY)

The distance traveled by light in a vacuum during one year. Approximately 9.47 x 10^12 km.

Big Bang

The event that occurred 13.7 billion years ago, creating space, time, matter, and energy.

Galaxies

Regions of the Universe where there are billions of celestial bodies (planets, asteroids, comets), gases, interstellar dust, stars, and so on.

Galactic Clusters

Small groups that galaxies are grouped into.

Superclusters

Bigger structures that Clusters are clumped into

Elliptical Galaxies

Galaxies containing few young stars, little gas and dust but many old red stars with little rotation and no star formation.

Spiral Galaxies

Galaxies containing a lot of bright young stars, rich in gas and interstellar dust, with huge rotating, flattened systems.

Irregular Galaxies

Galaxies located near large galaxies, disturbed and changed in appearance.

Stars

Giant balls of gas that represent the building blocks of galaxies, responsible for the production and distribution of elements.

Luminosity

Expresses the total amount of energy that a star radiates into space per unit of time (power).

Absolute Magnitude

Brightness a star would appear if placed at a standard distance of 32.6 LY from Earth.

Apparent Magnitude

A star's brightness as seen from Earth, depending on absolute magnitude and distance.

Hertzsprung-Russell (H-R) Diagram

A diagram showing the relationship between a star's temperature and absolute magnitude, indicating its physical properties.

Population I stars

Stars located in the central disk of the galaxy with all ages and many young stars; richer in heavy elements.

Population II stars

Stars located in the halo of the central zone of the galaxy, mainly old and poorer in heavy elements.

Nebulae

Clouds composed mostly of Hydrogen and Helium with small amounts of heavier atoms (C, N, O) where stars are born.

Protostar

A star in its early stages of formation, resulting from the collapse and rotation of a nebula.

Main Sequence

The phase when a star gets its energy from hydrogen fusion reactions into helium, maintaining hydrostatic equilibrium.

Red Giant or Red Supergiant

A star that has expanded, with decreased surface temperature, after depleting hydrogen reserves in the core.

White Dwarf

The state when a star shrinks after passing through the red giant phase. Can shine for billions of years and eventually stop shining turning into black dwarf

Supernova

The explosion when a massive star undergoes causing the formation of heavy elements.

Neutron Star

The end form a massive star takes. It is a very dense body.

Kuiper Belt

A zone of icy debris beyond Neptune's orbit, between 30 to 50 AU from the Sun.

Oort Cloud

A large, spherical region of icy debris that surrounds the solar system, ranging from 5,000 to 100,000 AU from the Sun.

Comets

Debris from the formation of the solar system formed of rocky materials, dust and ice with elliptical orbits.

Differentiation of the Earth

The process by which Earth settled into organized layers with the densest materials sinking to the center and less dense materials floating to the surface.

Mohorovicic Discontinuity (MOHO)

The boundary between the Earth's crust and the mantle.

Gutenberg Discontinuity

The boundary between the Earth's mantle and the core.

Lehmann Discontinuity

The boundary between the Earth's inner core and the outer core.

Lithosphere

The Earth's outer shell, composed of the crust and the uppermost solid part of the mantle.

Asthenosphere

A hot, plastic layer in the upper mantle that behaves like a very thick liquid.

Continental Drift

Theory by Alfred Wegener that all land masses were once united in one megacontinent called Pangea.

Plate Tectonics

A theory that states that deformations of the lithosphere are related to convection cells in the plastic mantle (asthenosphere).

Divergent Boundary

Where two plates are moving away from each other, with new crust rising up to fill the gap.

Convergent Boundary

Where two plates are moving towards each other which may cause one plate to slide under another.

Subduction

The process where the oldest and densest oceanic plate sinks under the other to form a subduction zone.

Transforming Boundary

Where two plates move laterally against each other; crust is neither created nor destroyed.

Earthquake

Sudden movement of large blocks of the Earth’s crust

Focus Point (Earthquake)

The place of rupture where the earthquake actually occurs.

Epicenter (Earthquake)

The point on the Earth's surface vertically above the focus point.

Body Waves

Seismic waves that cross both the interior of the Earth.

P Waves

Seismic waves that are compression waves; the soil particles move in a forward-backward motion in the direction of wave motion.

S Waves

Seismic waves that are shear waves; the particles oscillate in a vertical plane with respect to the propagation of the wave. They can only move through solid materials.

Surface Waves

Seismic waves that appear last and can produce the strongest vibrations, especially in densely populated areas.

Tsunami

A destructive phenomenon caused by an underwater movement related to an earthquake, a volcanic eruption, or a landslide.

Volcanoes

Are systems that relate the surface of the globe to internal areas where the materials are at a temperature that allows them to fuse.

Hotspot Volcanism

Intraplate volcanism, found mostly on oceanic plates that produces the melting of the mantle to create chains of volcanoes.

Eruptive or Magmatic Rocks

Rocks that crystallize from magma (a melted mixture of mineral matter and gas).

Sedimentary Rocks

Rocks formed on the surface of the Earth that result either from the precipitation of elements dissolved in water or the accumulation of debris from the erosion of surface rocks.

Metamorphic Rocks

Rocks, which come from the transformation in depth, under the effect of the increase of temperature and pressure, of the two other groups of rocks, with crystallization of new minerals.

Deformation of Rocks

When subjected to stress, the earth's crust is deformed plastically or brittlely.

Tension Constraints

These have the effect of stretching the material when deforming rocks.

Compression Constraints

These are caused when forces converge when deforming rocks.

Shear Stresses

These push a rock in two opposite directions when deforming rocks, causing a breakage or a change of shape.

Folds (Rock Deformation)

Formed by compression forces. Most visible in rocks containing layers.

Faults (Rock Deformation)

May be due to stress of tension, compression or shear when deforming rocks.

Erosion and Isostacy

Removal of a quantity of materials on the surface of a continent that leads to a rebalancing of the masses by the rise of the continental lithosphere.

Earth's Atmosphere

Atmosphere is an extremely thin gaseous envelope surrounding the globe.

Troposphere

The Earth's lowest atmospheric layer, where temperature generally decreases with altitude and where most weather occurs.

Stratosphere

The Earth's second atmospheric layer, containing the ozone layer that protects life from ultraviolet radiation.

Mesosphere

The Earth's third atmospheric layer, which is characterized by decreasing temperature with height.

Thermosphere

The uppermost layer of the atmosphere, in which temperature increases as altitude increases.

Greenhouse Gases (GHGs)

Gas that plays an important role in the terrestrial biosphere

Atmospheric and oceanic Circulation

It is the atmospheric and oceanic circulation that distributes excesses energy from low latitudes to high latitudes

Hadley cell

Cell characterized by the strong ascending hot and humid equatorial air and the descent of dry air around the latitude 30 of the tropics.

Ferrel's cell

Part of the tropical air that continues its path north to latitudes 60. LP areas.

The Polar Cell

Cell type characterized by the upward current (LP) at latitudes 60 which descends at the poles (HP). .