Overview
This lecture reviews and explains all questions from the January 21st, 2025 Earth Science Regents exam, covering key earth science concepts, test strategies, and how to use the reference tables.
Astronomy & Space
- Ceres, a dwarf planet, is located between Mars and Jupiter.
- Most galaxies show a red shift, indicating they are moving away from us.
- Terrestrial planets are small, rocky, and high density; Jovian planets are large and low density.
- Foucault pendulum demonstrates Earth's rotation.
- Changing constellations during the year is due to Earth's revolution around the Sun.
- The altitude of Polaris in NY changes with latitude.
- The shadow of a stick is always cast in the direction opposite the Sun.
- All stars appear to revolve around Polaris, which is above the North Pole.
- Time zones shift by 1 hour for every 15° longitude (east increases, west decreases).
Earth's Atmosphere & Weather
- Evaporation and transpiration add water vapor to the atmosphere.
- Dew point and relative humidity can be determined using the reference table's psychrometric chart.
- Air pressure code on station models: add 10 if first digit is 0–4; add 9 if 5–9; place decimal before last digit.
- Jet streams and weather in the US flow west to east.
- Improved extreme weather prediction is due to advanced computer models.
- Dark, rough surfaces absorb more insolation; light, smooth surfaces reflect more.
- Ocean currents are caused by uneven heating and Coriolis effect: clockwise in the Northern Hemisphere and counterclockwise in the Southern.
- Burning fossil fuels adds greenhouse gases.
Geology & Earth Processes
- Water moderates temperature due to higher specific heat compared to land.
- Geologic time divisions are mainly based on fossil evidence.
- Thick evaporite layers in NY were deposited during the Silurian period.
- S-waves only travel through solids; their absence in the outer core indicates it's liquid.
- The Pacific Plate is subducting under the Philippine Plate at the Mariana Trench.
- Harder minerals, like olivine, resist weathering the most.
- Glaciers cause parallel scratches; wind causes pits; water rounds rocks.
- Leeward (downwind) side of mountains is drier and warmer due to rain shadow effect.
Earth’s Surface & Mapping
- Oldest bedrock is furthest from the ridge in oceanic crust.
- Differences in NY state landscapes are due to bedrock structure and composition.
- Water flows fastest where contour lines are closest (steepest slope).
- Metamorphic rocks with banding are called foliated.
- The internal arrangement of atoms determines mineral hardness.
- Organic sedimentary rocks: limestone and bituminous coal.
Hydrology & Landscapes
- Sand dunes are formed by wind erosion.
- Delta forms at the mouth of a river entering an ocean.
- Increasing bead size decreases water retention (inverse relationship).
- Pebbles, sand, silt, and clay can be transported at 100 cm/s stream velocity.
Plate Tectonics & Earth History
- Convection currents beneath divergent plates cause plates to move apart.
- The Antarctic Circumpolar Current influences Bouvet Island's climate.
- India moved northeast after Pangaea began breaking up.
- Index fossils identify specific geologic periods.
Meteorology & Climate Patterns
- Warm air forced above a cold front forms clouds (100% relative humidity inside).
- Draw isotherms by connecting equal temperature values.
- High elevation causes colder climates, e.g., Rocky Mountains.
The Moon & Tides
- The Moon’s phase cycle is 29.5 days.
- The Moon has an elliptical orbit (distance from Earth varies).
- Gravitational pull of the Moon causes tides; high tides are roughly 13 hours apart.
Key Terms & Definitions
- Red Shift — Light from objects moving away is shifted to longer (red) wavelengths.
- Foucault Pendulum — A device demonstrating Earth's rotation.
- Insolation — Incoming solar radiation.
- Dew Point — Temperature at which air becomes saturated with moisture.
- Subduction — One tectonic plate moves under another.
- Specific Heat — Amount of heat needed to raise the temperature of a substance.
- Isotherm — Line connecting points of equal temperature.
- Metamorphism — Change in rocks by heat and pressure.
- Foliation — Banding in metamorphic rocks.
Action Items / Next Steps
- Review Earth Science reference tables (planet data, rock charts, tides, etc.).
- Memorize key processes: nuclear fusion, weathering, rock cycle steps, tides.
- Practice using maps, reading graphs, and interpreting diagrams.
- Complete any assigned readings or practice exams as directed by your teacher.