Earth Science Regents Review Sheet

The Earth Science Regents is a reading test in disguise — of the ESRT. Learn to navigate it and you're already 40% there.

Practice Earth Science free Reference & formulas

Big ideas

Every layer of Earth's story is written in rocks and stars. The ESRT is your codebook.
Weather is short-term, day-to-day. Climate is long-term average. Don't confuse them.
Plate tectonics powers earthquakes, volcanoes, and mountain-building. Learn the three boundary types cold.

Astronomy & Earth in space

Earth spins, orbits, tilts. Every 'why is it colder in December?' answer traces back to axial tilt.

Rotation vs revolution

Rotation = Earth spinning (24 hr, day/night). Revolution = orbit around sun (365.25 days, years).

Example: Cause of seasons? → Axial tilt (23.5°) + revolution — NOT distance from sun

Kepler's laws

Orbits are ELLIPSES with the sun at one focus. Planets move FASTER when closer to sun.

Example: Earth in January (closer to sun) — faster or slower? → Faster

Moon phases

Depend on Sun-Earth-Moon geometry. New (moon between Sun & Earth) → Waxing → Full (Earth between) → Waning.

Example: Full moon — where's the moon? → Opposite side of Earth from the sun

Eclipses

Solar: moon between Sun & Earth (new moon). Lunar: Earth between Sun & moon (full moon).

Example: Lunar eclipse phase? → Full moon

Trap: Distance from sun doesn't cause seasons. Northern hemisphere's summer coincides with Earth being FARTHER from sun.

Tip: The North Star (Polaris) sits directly above the North Pole. Its altitude equals your latitude.

Weather & climate

Air masses, fronts, and the water cycle. Read the station model and everything else follows.

Air mass types

cP = cold + dry. mT = warm + moist. Continental (c) = dry, Maritime (m) = moist. Polar (P) = cold, Tropical (T) = warm.

Example: 'mT' is what? → Warm and moist — comes from tropical ocean

Fronts

Cold front: cold air pushes warm up FAST → thunderstorms. Warm front: warm slides over cold → drizzly and long.

Example: Sudden intense thunderstorm? → Cold front passing

Water cycle

Evaporation (liquid → gas, needs energy) → condensation (gas → liquid, releases energy) → precipitation → runoff/groundwater.

Example: Fog forming = ? → Condensation

Station model

Center circle = cloud cover. Number to upper-left = temperature. Lower-left = dew point. Right = pressure (last 3 digits).

Example: Pressure code '045' → 1004.5 mb (prepend 10 or 9)

Trap: High pressure = clear, dry, fair weather. Low pressure = clouds and precipitation. Don't confuse them.

Tip: Wind blows FROM high pressure TO low pressure. Isobars close together = strong wind.

Plate tectonics

Earth's surface is cracked into plates that move. All three boundary types are in the ESRT.

Divergent boundary

Plates PULL APART. Mid-ocean ridges. New crust forms. Mostly non-explosive volcanoes.

Example: Mid-Atlantic Ridge? → Divergent

Convergent boundary

Plates COLLIDE. Ocean + continent → subduction, trench, mountains. Continent + continent → giant mountains (Himalayas).

Example: Deepest ocean trenches? → Convergent (subduction)

Transform boundary

Plates SLIDE past each other. Earthquakes but no volcanoes. San Andreas fault.

Example: California earthquakes? → Transform

Hot spots

Fixed plume of magma under moving plates. Creates island chains (Hawaii).

Example: Why do Hawaiian islands get older going west? → Plate moved west over hot spot

Trap: Volcanoes ONLY at divergent and convergent boundaries. Not at transform.

Tip: The ESRT has a map of tectonic plates. Every plate-tectonics question is a lookup — practice locating fast.

Rocks, minerals, and the rock cycle

Three rock families: igneous (magma cools), sedimentary (bits stick together), metamorphic (heat + pressure).

Igneous

Cooled magma/lava. Intrusive = slow-cooling underground → LARGE crystals (granite). Extrusive = fast-cooling on surface → small crystals (basalt).

Example: Rock with tiny crystals — where'd it form? → Surface (extrusive)

Sedimentary

Layers of sediment compacted and cemented. Contains fossils. Grain size tells you where it formed.

Example: Shale is made of what grain size? → Clay-sized (very fine)

Metamorphic

Any rock + heat + pressure = new rock. Foliated (banded, like gneiss/schist) or non-foliated (like marble/quartzite).

Example: Limestone under heat & pressure? → Marble

Mineral identification

Use the ESRT mineral chart: color, hardness, cleavage/fracture, luster, specific properties.

Example: Very hard, no cleavage, common in beach sand → Quartz

Trap: Grain size is about CRYSTAL size in igneous rocks — slow-cool = BIG crystals, fast-cool = small.

Tip: For rock cycle questions, remember: any rock can become any other rock with the right conditions.

Landscapes, erosion, and using the ESRT

Wind, water, ice sculpt the land. And every problem is a table lookup.

Agents of erosion

Water (most common), wind, ice (glaciers, huge boulders), gravity (landslides).

Example: U-shaped valley? → Carved by a glacier

Streams

Fast water carries LARGER particles. Slower water drops them first. Meanders form on flat land.

Example: River slows down. What settles first? → Boulders (heaviest first)

Landscape regions of NYS

Adirondacks, Catskills, Tug Hill, Allegheny Plateau, Erie-Ontario Lowlands, etc. — Learn the ESRT map cold.

Example: Highest elevations in NYS? → Adirondacks

Percent error

\text{Percent error} = \dfrac{|\text{measured} - \text{accepted}|}{\text{accepted}} \times 100

On the reference tables. Used constantly on the exam.

Example: Measured 4.9, accepted 5.0 → |4.9 − 5|/5 × 100 = 2%

Trap: Percent error uses ACCEPTED in the denominator, not measured. Regents will trick you.

Tip: Every Earth Science Regents has 5+ ESRT lookup questions. Time yourself to find any table in under 15 seconds.

Frequently asked questions

How should I study for the Earth Science Regents?

Work real past-exam questions by topic, review this one-page summary of the must-know concepts, and read the worked solution every time you miss one. The exam reuses the same ideas year after year.