Comprehensive Study Guide for NYS Regents Earth Science Exam (January 2026)

Examination Overview and Administrative Protocols

• Examination Title: Regents High School Examination: Physical Setting Earth Science.

• Date and Time: Friday, January 23, 2026, from $9:15\,a.m.$ to $12:15\,p.m.$

• Required Materials:

  • $2011$ Edition Reference Tables for Physical Setting/Earth Science.

  • Four-function or scientific calculator.

  • Pencil (for graphs and drawings).

  • Pen (for all other written responses in the answer booklet).

• Prohibited Items: Possession or use of any communications devices is strictly prohibited. Use will result in invalidation of the examination and no score being calculated.

• Examination Components:

  • Part A and Part B–1: Multiple-choice questions recorded on a separate answer sheet.

  • Part B–2 and Part C: Short-answer and constructed-response questions recorded in a separate answer booklet.

• Declaration: Students must sign a declaration on the answer sheet stating they had no unlawful prior knowledge of questions/answers and provided/received no assistance.

Astronomy and Celestial Mechanics

• Heliocentric Model: This model describes planets traveling around the Sun in eccentric orbits.

• Nuclear Fusion: The energy-producing process inside the Sun that combines lighter elements into heavier elements, specifically converting hydrogen into helium.

• Foucault Pendulum: Provides evidence of Earth's rotation on its axis as the swing appears to change direction over time.

• Star Trails: Circular paths of stars captured in time-exposure photography. When looking North, stars appear to rotate around Polaris due to Earth's rotation.

• Constellations: The seasonal visibility of various constellations (such as Aries, Pisces, Aquarius, etc.) is caused by Earth's revolution around the Sun in its orbit.

• Earth's Orbit and Tilt:

  • Earth's axis is tilted at $23.5^\circ$ relative to its orbital plane.

  • During the December solstice (December $21$), the North Pole is tilted away from the Sun, while the South Pole is tilted toward it.

• Planetary Comparisons:

  • Terrestrial Planets: Higher density, smaller mass, and composed mainly of rock.

  • Jovian Planets: Lower density, larger mass, and composed mainly of gases/ices.

• Halley's Comet:

  • Perihelion: The point in an orbit closest to the Sun.

  • Gravitational Force: The force between the comet and the Sun increases as the distance between them decreases (approaching perihelion) and decreases as they move apart.

• The Moon:

  • Cycle of Phases: It takes approximately $29.5$ days for the Moon to complete one full cycle of phases.

  • Lunar Eclipse: Occurs when the Moon is in the Full Moon position (position E, where Earth is between the Sun and the Moon).

  • Syncronous Rotation: The same side of the Moon always faces Earth because its period of rotation is equal to its period of revolution around Earth.

Meteorology and Atmosphere

• Ocean Tides: Cycles of high and low tides occur approximately every $6$ hours and $12.5$ minutes. If a high tide occurs at $7:49\,p.m.$, the next low tide will occur roughly $6$ hours and $40$ minutes later at around $8:29\,a.m.$

• Earth's Early Atmosphere: Inferred to have formed primarily through the outgassing of gases from Earth's interior.

• Atmospheric Structure:

  • Stratosphere: Contains approximately $90\%$ of atmospheric ozone.

  • Ozone Altitudes: Most ozone is located between the altitudes of $12\,km$ and $50\,km$.

• Meteorological Data and Instruments:

  • Psychrometer: An instrument with a wet-bulb and dry-bulb thermometer used to determine relative humidity and dew point.

  • Relative Humidity: When relative humidity is $100\%$, the dry-bulb and wet-bulb temperatures are identical.

  • Station Models: Represent weather data. A model showing overcast skies with drizzle and visibility of $\frac{1}{4}$ mile indicates specific symbols for cloud cover and precipitation.

• Water Cycle and Energy:

  • Latent Heat of Vaporization: The process of water gaining $2260\,J/g$ of heat energy to change into water vapor.

  • Latent Heat of Fusion: Involves $334\,J/g$ of heat energy (used for melting or released during freezing).

• Climate Factors:

  • Elevation: High elevation (e.g., Chimborazo volcano) allows for snow at the equator.

  • Proximity to Water: Bodies of water (like those surrounding Long Island) moderate temperatures, creating a smaller temperature range compared to inland areas like central New York.

  • Insolation Absorption: Light-colored and smooth surfaces absorb the least amount of solar radiation.

  • Transpiration: The process by which water vapor exits the leaves of trees.

• El Niño Events:

  • Characterized by a weakening of the trade winds.

  • Causes a change in air pressure over Australia (tending toward higher pressure compared to normal conditions).

  • Causes rising moist air to expand and cool to the dew point, resulting in condensation and cloud formation.

Plate Tectonics and Geophysics

• Lithospheric Plate Movement: Driven by convection currents located in the plastic mantle (asthenosphere).

• Crustal Characteristics:

  • Oceanic Crust: More dense and thinner than continental crust; primarily basaltic.

  • Continental Crust: Less dense and thicker; primarily granitic.

• Plate Boundaries:

  • Convergent (Subduction): Found at the South Sandwich Trench where one plate sinks beneath the Sandwich Plate.

  • Divergent: Represented by spreading centers like the Mid-Atlantic Ridge.

  • Transform: Where plates slide past each other.

• Magnetic Reversals: Earth's magnetic poles last reversed approximately $780,000$ years ago; evidence is preserved in oceanic basaltic bedrock patterns near spreading centers.

• Seismology:

  • P-waves: Primary/compression waves that arrive first at a recording station.

  • S-waves: Secondary/shear waves that arrive after P-waves.

  • Epicenter: Location on the surface directly above the earthquake focus. The British Isles earthquake epicenter featured in the exam is located at $51^\circ N, 1^\circ E$.

Earth History and the Fossil Record

• Geologic Progression: Preserved life-forms show a progression from simple to more complex organisms, providing evidence for the evolution of life.

• Organism Longevity: In terms of total geologic time, humans have existed for the shortest period compared to birds, dinosaurs, or placoderm fish.

• Index Fossils:

  • Criteria: To be useful for correlation, a fossil must have been geographically widespread and existed for a short period of geologic time.

  • Example: Elliptocephala is an index fossil classified as a Cambrian-age trilobite.

• Relative Dating: Uses principles like superposition (oldest layers on bottom) and cross-cutting relationships. The sequence from oldest to youngest for the provided cross-section is Z, V, W, X, Y.

• Radioactive Decay (Uranium-238):

  • $U-238$ decays into Lead-206 ($Pb-206$).

  • As the amount of the original radioactive isotope decreases, the amount of the disintegration product increases.

  • After $1$ half-life: $50\%$ parent, $50\%$ daughter product.

  • After $5$ half-lives: $3.125\%$ parent, $96.875\%$ daughter product.

Mineralogy and Petrology

• Identification Properties:

  • Hardness: Graphite is much softer than magnetite.

  • Streak: Graphite leaves a black/gray streak; magnetite leaves a black streak but is magnetic.

  • Luster: Both can exhibit metallic luster.

• Rock Textures:

  • Vesicular: Describes igneous rocks containing gas pockets (e.g., scoria, vesicular basalt).

  • Foliated: Describes metamorphic rocks with alignment of minerals or banding (e.g., gneiss).

  • Gneiss: Typically exhibits a foliated texture and a coarse grain size.

• Bluestone (New York State):

  • A Devonian-age sandstone found in southeastern New York.

  • Composition: Primarily quartz-feldspar sandstone, making it dense and durable.

  • Color: Varies from greenish gray to grayish-red purple (blue is not a diagnostic property).

  • Formation Processes: Compaction and cementation following the deposition of sand grains.

• Travertine: A variety of limestone found in Saratoga Springs; its primary mineral constituent is calcite.

Surface Processes and Landscapes

• Weathering and Erosion:

  • Roundness: Sediments become rounded through the process of abrasion as they are transported by water.

  • Meanders: Erosion occurs on the outside of a curve where water velocity is higher; deposition occurs on the inside of the curve where velocity is lower.

  • Glacial Evidence: Parallel gouges (striations) on bedrock are formed by large boulders dragged across the surface by glaciers.

• Deposition in Lakes: When a river enters a lake, larger particles settle first (near the shore), and smaller particles settle further out (horizontal sorting).

• Landforms: Rivers entering large bodies of water produce deltas.

• Hydrology:

  • Watersheds: Areas of land that drain into specific rivers. In New York, Watershed B is the Mohawk River and Watershed J is the Susquehanna River.

  • Velocity: A minimum stream velocity is required to move particles of specific sizes. For particles $0.05\,cm$ in diameter, a specific velocity must be maintained according to the Reference Tables.

• Topographic Maps:

  • Contour Interval: The vertical distance between contour lines (e.g., $20\,ft$ or $100\,ft$ depending on the map scale).

  • Gradient: Closely spaced contour lines indicate a steeper slope.

  • Stream Flow: Streams flow opposite to the ‘V’ shape formed by contour lines crossing the stream channel.

Environmental Change and Projects

• The Great Green Wall:

  • Goal: To combat desertification (the expansion of deserts) in the Sahel region, south of the Sahara Desert.

  • Scope: A line of trees $10$ miles wide and $4815$ miles long.

  • Carbon Sequestration: Trees absorb $CO_2$ during photosynthesis; by $2030$, it is expected they will absorb $250$ metric tons of carbon dioxide.

  • Erosion Control: Roots hold soil in place, and stone barriers help raise the water table.

• Weather Hazards:

  • Blizzards: Emergency preparedeness actions include stocking up on food/water, ensuring a backup heat source, and staying off the roads.