Geology, Meteorology & Astronomy Review

90 question-and-answer flashcards covering key concepts in geology, hydrosphere, atmosphere, meteorology, and astronomy.

What science studies the Earth's structure, history, and processes?

Geology

Name the three principal parts of the Earth system.

Geosphere, Hydrosphere, Atmosphere

What is the outermost solid layer of Earth?

The crust

Approximately how deep does the Earth’s crust extend below sea level?

Up to about 100 km

Which crust type forms the continents and is rich in silica and aluminum?

Continental crust (sial)

Which crust type lies beneath the oceans and is rich in silica and magnesium?

Oceanic crust (sima)

What rigid region includes the crust and the uppermost mantle?

Lithosphere

What semi-solid layer beneath the lithosphere allows rocks to flow?

Asthenosphere

Which layer of Earth extends to ~2,900 km depth and is mostly molten rock?

The mantle

Which Earth layer is composed mostly of molten iron and nickel?

Outer core

Which innermost layer is solid despite its high temperature?

Inner core

What are the rigid pieces of crust and upper mantle that move over Earth’s surface called?

Tectonic plates

What theory explains large-scale motion of Earth’s lithosphere?

Plate tectonics

What was the name of the single supercontinent proposed by Wegener?

Pangea

What vast ocean surrounded Pangea?

Panthalassa

What process creates new ocean floor when plates move apart?

Sea-floor spreading

At which boundary do plates move away from each other, creating new crust?

Divergent boundary

Which boundary destroys crust as plates collide?

Convergent boundary

What landform commonly forms at an oceanic-continental convergent boundary?

A trench

What landform results from continental-continental convergence?

Mountain ranges (and volcanoes)

At what boundary do plates slide past each other without creating or destroying crust?

Transform boundary

What is the point beneath Earth’s surface where an earthquake originates?

Focus

What is the surface point directly above an earthquake’s focus?

Epicenter

Which seismic waves are compressional, travel fastest, and move through all media?

Primary (P) waves

Which seismic waves are shear, slower than P waves, and travel only through solids?

Secondary (S) waves

Name the two main types of surface seismic waves.

Rayleigh waves and Love waves

Which numerical scale measures earthquake magnitude using seismographs?

Richter scale

Which earthquake scale is based on human observations of damage?

Mercalli scale

What term describes huge sea waves caused by sudden water displacement?

Tsunami

What steep, symmetrical cone volcano is built of alternating lava and ash layers?

Composite (stratovolcano)

What small, steep volcano is made of loose cinders around a single vent?

Cinder cone

What broad, gently sloping volcano is built almost entirely of fluid lava?

Shield volcano

Which rock type forms when molten magma or lava solidifies?

Igneous rock

What igneous rocks crystallize underground and have large crystals?

Intrusive igneous rocks

What igneous rocks cool at the surface and may form volcanic glass?

Extrusive igneous rocks

Which rock type forms from accumulated sediments or chemical precipitation?

Sedimentary rock

Which rock type is altered by heat and pressure within Earth?

Metamorphic rock

What model illustrates how rocks transform from one type to another?

The rock cycle

What naturally occurring inorganic solid has a specific composition and properties?

A mineral

What scale ranks minerals from 1 (talc) to 10 (diamond) for hardness?

Mohs scale of hardness

What mineral property is its color in powdered form?

Streak

What term describes the way a mineral reflects light?

Luster

What percentage of Earth’s water is contained in the oceans?

About 97 %

What proportion of Earth’s water is freshwater?

About 3 %

Where is roughly two-thirds of Earth’s freshwater stored?

In glaciers and ice caps

What is the underground region that is always filled with water called?

Zone of saturation (groundwater)

What name is given to the upper surface of groundwater?

Water table

Which water-cycle process converts liquid water to vapor?

Evaporation

Which process forms clouds by converting water vapor to liquid droplets?

Condensation

What term covers rain, snow, or hail falling to Earth?

Precipitation

What gases constitute about 78 % and 21 % of the atmosphere, respectively?

Nitrogen and oxygen

In which atmospheric layer does almost all weather occur?

Troposphere

Which layer contains the ozone layer?

Stratosphere

Which layer slows meteors and has very low temperatures?

Mesosphere

Which very hot layer above 85 km contains the ionosphere?

Thermosphere

What outermost atmospheric layer gradually merges with space?

Exosphere

What magnetic field region shields Earth from solar wind?

Magnetosphere

Define weather.

The average atmospheric conditions at a specific place and time

Define climate.

The average atmospheric conditions of a region over a long period

During the day, what local wind blows from sea to land?

Sea breeze

At night, what local wind blows from land to sea?

Land breeze

What rotating low-pressure storm with strong winds and rain forms over large areas?

Cyclone

What violent, twisting funnel of air forms over land?

Tornado

How many categories are in the Philippine Public Storm Warning System (PSWS)?

Five

What wind-speed range corresponds to PSWS Signal #3?

121–170 kph

Which Philippine department oversees PAGASA and PHIVOLCS?

Department of Science and Technology (DOST)

Which agency is responsible for disaster rehabilitation and recovery?

National Economic and Development Authority (NEDA)

How long does one complete rotation of Earth on its axis take?

About 24 hours (23 h 56 m 4 s)

How long is one revolution of Earth around the Sun?

About 365.25 days

According to Steno’s principle of superposition, which sedimentary layer is youngest?

The topmost undisturbed layer

What date marks the longest day in the Northern Hemisphere?

Summer solstice (around June 21)

What term describes the Moon’s farthest point from Earth?

Apogee

Which tide features very high high tides and very low low tides?

Spring tide

Which eclipse occurs when the Moon blocks the Sun?

Solar eclipse

What is the alignment for a lunar eclipse?

Sun — Earth — Moon

Which two elements compose most of the Sun?

Hydrogen and helium

Name the four terrestrial planets.

Mercury, Venus, Earth, and Mars

Which planet is famous for its Great Red Spot?

Jupiter

Which planet has the most extensive ring system?

Saturn

Which blue planet shows the Great Dark Spot?

Neptune

What icy objects develop visible tails when near the Sun?

Comets

What galaxy contains our Solar System?

The Milky Way

List the four main galaxy shapes.

Spiral, barred spiral, elliptical, and irregular

What life-cycle stage describes most stars fusing hydrogen steadily?

Main sequence

What compact remnant is left when a small-to-medium star dies?

White dwarf

What explosive event marks the death of a massive star?

Supernova

What extremely dense object, from which not even light can escape, can remain after a supernova?

Black hole

What theory says the universe began from a singular, massive explosion?

The Big Bang theory

What distance does light travel in one year, equal to 9.46 × 10¹² km?

One light-year