World Geography Lecture Flashcards

A Comprehensive collection of vocabulary flashcards covering Earth's origin, celestial objects, geology, atmospheric systems, and global physical geography based on the lecture notes.

Nebular Hypothesis

The early theory given by Immanuel Kant and revised by Laplace stating that the Sun and planets formed from a large rotating cloud of gas and dust.

Planetesimals

Small solid bodies formed from cooled material pulled from the Sun, which combined to form the planets according to Chamberlain and Moulton's hypothesis.

Big Bang Theory

The modern theory by Georges Lemaitre stating the universe began $13.8\,\text{billion years}$ ago with a huge explosion from a single point.

Dwarf Planets

Celestial objects that orbit the Sun and are nearly round but do not clear their orbital path, such as Pluto, Eris, and Ceres.

Quasars

Very bright and powerful centers of distant galaxies powered by supermassive black holes.

Geoid

The actual shape of the Earth, described as an oblate spheroid that is slightly flat at the poles and bulging at the equator.

Goldilocks Zone

The habitable region around a star where temperatures are such that liquid water can exist on a planet's surface.

Earth's Axial Tilt

The specific angle of $66\frac{1}{2}^{\circ}$ that Earth's axis makes with its orbital plane.

Tropic of Cancer

The northern boundary of the tropics located at $23\frac{1}{2}^{\circ}\,N$ latitude.

International Date Line

The line at $180^{\circ}$ longitude where crossing from West to East results in gaining one day.

Perihelion

The point in Earth's elliptical orbit where it is closest to the Sun, occurring on $3\,\text{January}$.

Equinox

Occurring on $21\,\text{March}$ and $23\,\text{September}$, when the Sun shines directly over the equator and day and night are equal.

SIAL

The composition of the continental crust, primarily consisting of silica and aluminium with an average density of $3\,\text{g/cm}^3$.

SIMA

The composition of the oceanic crust, primarily consisting of silica and magnesium with an average density of $2.7\,\text{g/cm}^3$.

Asthenosphere

The layer within the upper mantle that serves as the main source of magma for volcanic activity.

Lithosphere

The layer consisting of the Earth's crust plus the uppermost solid mantle, ranging from $10$ to $200\,\text{km}$ in thickness.

NIFE

The composition of the Earth's core, primarily consisting of nickel (Ni) and iron (Fe).

Lithification

The geological process through which sediments are deposited, compacted, and hardened into sedimentary rocks.

Focus

Also known as the hypocentre, the specific point inside the Earth where an earthquake originates.

P-Waves

Primary seismic waves that are longitudinal, the fastest to travel, and can move through solids, liquids, and gases.

S-Wave Shadow Zone

The area beyond $105^{\circ}$ from an earthquake's epicentre where S-waves cannot be detected because they do not pass through the liquid outer core.

Batholiths

Very large, deep-seated granite bodies that are the remnants of old magma chambers.

Pangaea

The ancient supercontinent that Alfred Wegener proposed existed before splitting into Laurasia and Gondwanaland.

ITCZ

The Intertropical Convergence Zone; a low-pressure zone near the equator where NE and SE trade winds meet and rise.

Jet Streams

Fast, narrow upper-air westerly winds traveling at $400$ to $500\,\text{km/h}$ formed by temperature differences and the Coriolis force.

Albedo

A measure of surface reflectivity that affects the amount of solar energy absorbed by Earth.

Relative Humidity

The moisture present in the air expressed as a percentage of the air's moisture-holding capacity at a specific temperature.

Cirrus Clouds

Thin, feather-like white clouds made of ice crystals found at high altitudes between $8,000$ and $12,000\,m$.

Taiga

Also known as the Siberian climate, a cool temperate continental region characterized by coniferous forests and extremely cold winters.

Abyssal Plain

A gently sloping flat area of the deep ocean floor covering about $40\%$ of its area at depths between $3,000$ and $6,000\,m$.

Halocline

The vertical zone in the ocean where salinity increases sharply with depth.

Spring Tides

Exceptionally high and low tides that occur when the Sun, Moon, and Earth align in a straight line during Full or New Moon.

49th Parallel

The international border line separating the USA and Canada.

Radcliffe Line

The international boundary line between India and Pakistan.

Mariana Trench

The deepest part of the world's oceans, located at a convergent plate boundary in the Pacific Ocean.