The Reference Tables Are an Open-Book Cheat Sheet You Must Learn to Read
The single biggest score swing on the New York Earth Science Regents is not how much you memorized. It is how fast and accurately you can read the Earth Science Reference Tables (ESRT) under time pressure. Roughly half of the multiple-choice questions can be answered directly from a chart, graph, or equation in the booklet, and many constructed-response answers live or die on whether you pulled the correct value from the correct page.
This guide is a page-by-page tour of the ESRT as a problem-solving tool. For each chart, you will learn what it answers, how to read it, the exact question types it unlocks, and the mistakes that cost students points every June. If you are still deciding which exam version and which booklet you sit, read our companion guide on the Earth and Space Sciences transition and 2024 Reference Tables first. This article focuses on the table-reading skill itself, which transfers to either booklet.
The current legacy edition is the 2011 Edition Reference Tables for Physical Setting/Earth Science, still used for the Physical Setting exam through the transition. You can download it free from the NYSED reference tables page. The new Earth and Space Sciences exam uses a 2024 booklet with reorganized pages, but the reading moves below apply to both.
The Equations Page: Memorize Where, Not What
The ESRT prints every formula you need, so you should never rederive density, gradient, or eccentricity. You only need to know which page they live on and how to plug in.
- Eccentricity = distance between foci / length of major axis (d/L). This measures how flattened an orbit's ellipse is. A perfect circle has eccentricity 0; the closer to 1, the more stretched the orbit. Worked example: if the foci are 4 cm apart and the major axis is 10 cm, eccentricity = 4 / 10 = 0.40. The answer is always a decimal between 0 and 1 with no units. A common trap is dividing by the minor axis or forgetting it is unitless.
- Gradient = change in field value / distance. Use it for slope of the land on a topographic map or for any contour field. Worked example: two points 600 m and 200 m elevation that are 8 km apart give a gradient of (600 - 200) / 8 = 50 m/km.
- Rate of change = change in field value / time. Use it for how fast a stream rose or a temperature dropped.
- Density = mass / volume. A rock's density does not change when you break it, a classic distractor.
- Percent deviation from accepted value appears here too, for lab-style items.
Question types this unlocks: any "calculate the eccentricity/gradient/density" item, plus conceptual items that ask which orbit is most eccentric or which slope is steepest.
Radioactive Decay and Half-Lives: The Absolute-Age Page
The Radioactive Decay Data table lists the isotopes the exam uses and their half-lives. Know these four cold so you can sanity-check answers:
- Carbon-14: half-life 5,700 years, used to date once-living material up to roughly 50,000 years.
- Potassium-40: half-life 1.3 billion years, used for older rocks.
- Uranium-238: half-life 4.5 billion years, paired with lead-206.
- Rubidium-87: half-life 48.8 billion years, the longest on the table.
The companion decay graph shows the fraction of original radioactive material remaining versus number of half-lives. Worked example: a fossil contains 1/8 of its original Carbon-14. One eighth is three halvings (1 → 1/2 → 1/4 → 1/8), so three half-lives have passed: 3 × 5,700 = 17,100 years. The deadliest mistake is mixing isotopes: you cannot use Carbon-14 to date a billion-year-old granite, and you cannot use Uranium-238 to date a 10,000-year-old bone. Match the isotope's half-life to the age range in the question.
The Earthquake P-Wave and S-Wave Travel-Time Graph
This graph plots how long P-waves and S-waves take to travel a given distance from an epicenter. It answers three classic question types.
- Find distance to the epicenter from the time gap. Measure the difference in arrival times between the S-wave and P-wave, then slide that gap vertically on the graph until it fits exactly between the two curves; read the distance below. A larger S-minus-P gap means a farther epicenter.
- Find travel time for a known distance. Go up from the distance axis to a curve and read the time.
- Find origin time. Subtract the P-wave travel time from the recorded arrival time.
Worked example: if P arrives at 10:00:00 and S arrives 3 minutes 20 seconds later, find the S-P interval on the graph and read the epicenter distance (about 2,000 km). Common mistakes are confusing the P (faster, lower) and S (slower, upper) curves and reading minutes as seconds.
Generalized Landscape Regions of New York State
This map divides New York into plateaus, lowlands, and highlands. It pairs with the Geologic History and Bedrock pages. Question types: identify the landscape region of a city, infer the bedrock type and likely surface features, and explain why a plateau has horizontal layers while a highland shows distorted, metamorphosed rock. A frequent error is confusing landscape regions with the bedrock geology map; they are related but separate pages, and the exam tests both.
Rock and Mineral Identification Charts
Three linked charts do the heavy lifting for the rock cycle.
- Scheme for Igneous Rock Identification. Read it by grain size (top: coarse intrusive, bottom: fine or glassy extrusive) and by mineral composition and color (left: felsic and light, right: mafic and dark). To find granite, go to the coarse-grained, felsic, light-colored corner. Its extrusive twin with the same composition is rhyolite.
- Scheme for Sedimentary Rock Identification. Separates clastic rocks by particle size (conglomerate, sandstone, siltstone, shale) from chemical and biochemical rocks like limestone and rock salt.
- Scheme for Metamorphic Rock Identification. Distinguishes foliated (slate, schist, gneiss) from non-foliated (quartzite, marble) and ties each to its parent rock.
- Properties of Common Minerals. Use hardness, cleavage, luster, streak, and distinguishing characteristics to identify an unknown mineral, exactly as a geologist keys it out.
Question type: "A rock is coarse-grained, light-colored, and 60% feldspar; name it." Trace the chart rather than guessing from a memorized list. The biggest trap is jumping straight to the rock name without confirming both grain size and composition.
Rate of Deposition and the Relationship of Transported Particle Size to Water Velocity
This graph relates stream velocity to the largest particle a stream can carry. Faster water carries larger particles; as a stream slows, it deposits the largest particles first and the smallest last. Worked example: a stream flowing at 200 cm/s can transport pebbles and cobbles; slow it to 1 cm/s and only clay and silt stay suspended, so sand and larger sediment drop out. Question types: predict which sediment is deposited when velocity changes, or explain graded bedding and horizontal sorting in a delta. The classic mistake is reversing the relationship; remember that high energy carries big particles.
Properties of Water, Specific Heats, and the Dewpoint and Relative Humidity Tables
The Properties of Water box gives values such as the energy released or absorbed during freezing, melting, and vaporization, plus the specific heat of water (about 4.18 J/g·°C), the highest of the common Earth materials. That high specific heat is why coastal climates are milder than inland climates and why water heats and cools slowly.
The Dewpoint and Relative Humidity tables are read with two thermometer readings: the dry-bulb temperature and the difference between the dry-bulb and wet-bulb temperatures. Worked example: a dry-bulb of 20°C with a 6°C wet-bulb depression gives a dewpoint near 7°C and a relative humidity near 51%. When the depression is 0, the air is saturated and relative humidity is 100%. Question types: find dewpoint, find relative humidity, predict when condensation or fog forms, and relate dewpoint to actual moisture content. The most common error is using the wet-bulb temperature directly instead of the dry-bulb-minus-wet-bulb difference.
Planetary Data and Solar System Charts
The Solar System Data table lists each planet's mass, diameter, distance from the Sun, period of revolution, period of rotation, and eccentricity. Question types: compare orbital periods, identify which planet has the most eccentric orbit, or relate distance from the Sun to period of revolution. Pair this page with the eccentricity formula above. A common mistake is confusing period of revolution (one orbit around the Sun, a year) with period of rotation (one spin, a day).
Other High-Yield Pages
- Geologic History of New York State. A time scale of eras, periods, and index fossils. Use it to date a rock layer from its fossils or to order events.
- Tectonic Plates and Inferred Properties of Earth's Interior. Read plate boundaries, the depth and temperature of Earth's layers, and pressure with depth.
- Surface Ocean Currents and Planetary Wind and Moisture Belts. Explain climate, prevailing winds, and why deserts cluster near 30° latitude.
- Electromagnetic Spectrum and Selected Properties of Earth's Atmosphere. Read temperature, pressure, and altitude of atmospheric layers.
A Reference-Table Routine That Earns Points
Before you guess on any quantitative or chart-based item, run this loop:
- Name the quantity the question wants: eccentricity, gradient, age, distance, dewpoint, density, or rate.
- Ask, "Which ESRT page holds this?" and turn to it before you reason from memory.
- Pull the exact value or read the exact point off the graph.
- For constructed response, write the value, the page or relationship you used, and one sentence of Earth-science reasoning.
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