Reference Tables

Start here, because this is the biggest change. The older Earth Science tables opened with an equations page. The Reference Tables for Earth and Space Sciences do not. These formulas are still fair game on the exam, so they have to live in your head.

Practice these in the gradient lab, the density lab, and the eccentricity lab.

One table holds distance from the sun, period of revolution, period of rotation, orbital eccentricity, diameter, and axial tilt for every major body. Most solar system questions are lookups plus one comparison.

How to use it

1. Find the row for the object.
2. Read straight across to the column the question asks about.
3. For a comparison, read two rows and subtract or divide.

The Gravity and the Solar System chapter works from this table.

The H-R Diagram plots luminosity against surface temperature and sorts stars into families. Beside it is a key giving the temperature range of each spectral class, and page 5 models how stars of different masses live and die.

What to notice

• Temperature increases to the left, not the right. Blue O and B stars sit at the hot left edge; red M stars at the cool right.
• The main sequence runs diagonally from hot and bright down to cool and dim. Our sun sits on it.
• Giants and supergiants sit above the main sequence: cool but very luminous, because they are enormous.
• White dwarfs sit below: hot but dim, because they are tiny.

See it in the star color lab in Stars and the Universe.

This two-page spread is the busiest in the booklet and the most rewarding. It carries the eras, periods, and epochs with their dates, the events in New York, index fossils and their time ranges, and small maps showing where Earth’s landmasses sat.

How to work it

1. Find the time column first and locate the age or period in question.
2. Read across for life on Earth, New York events, and the rock record.
3. For a fossil question, find the fossil letter in the time distribution band and read the range it spans.

The Geologic History chapter builds on this spread.

Three maps in a row do most of the New York work on the exam, and they are meant to be read together.

• Page 8, Generalized Surface Bedrock Geology. Color gives the age and rock type of the bedrock. The oldest, Mesoproterozoic gneisses and marbles, are in the Adirondacks and the Hudson Highlands; the youngest, weakly consolidated gravels and sands, are on Long Island.
• Page 9, Energy and Mineral Resources. Where salt, gypsum, garnet, talc, iron, and the gas and oil fields are.
• Page 10, Geographic Province and Landscape Regions. The landscape regions, including the trap: the Catskills sit inside the Appalachian Plateau province.

The New York regions section in Landscapes walks all three maps.

Page 11 carries two models side by side: a layered model of Earth’s interior with depths and densities, and a cross section showing how that interior drives the surface.

Numbers worth knowing off this page

• Oceanic crust: about 5 to 15 km thick, near 3.0 g/cm³, basaltic.
• Continental crust: about 30 to 50 km thick, 2.7 to 2.9 g/cm³, granitic.
• The mantle reaches to 2900 km, where the fluid outer core begins.
• Density climbs with depth, reaching 12.8 to 13.1 g/cm³ in the solid inner core.

Explore it in the Earth interior visualization.

The radiometric dating table lists each parent isotope, its daughter product, its half-life, and what it can date. Below it, a world map marks selected hot spots.

Half-lives to recognize

• Carbon-14 to nitrogen-14: 5730 years, good to about 70,000 years, for organic material.
• Uranium-238 to lead-206: 4.5 billion years, for zircon and other uranium minerals.
• Potassium-40 to argon-40: 1.3 billion years.

Try the half-life lab, and see hot spots in Volcanoes.

This world map shows plate boundaries, their type, the direction plates move, and spreading rates in centimeters per year.

How to read it

1. Find the location and identify the nearest boundary.
2. Read the key to classify it: divergent, convergent, or transform.
3. At a convergent boundary, the symbol shows which plate overrides and which subducts.
4. Numbers along divergent boundaries give the total spreading rate.

Classify boundaries yourself in the boundary explorer.

Page 14 pairs Bowen’s Reaction Series with the Mineral Composition of Igneous Rocks chart. Page 15 is a single large Rock Cycle Infographic that names rocks from all three families and shows where each forms.

The igneous chart

• Read left to right, felsic to intermediate to mafic to ultramafic.
• Felsic rocks (granite, rhyolite) are high in silica, light colored, and lower in density.
• Mafic rocks (gabbro, basalt) are richer in iron and magnesium, dark, and denser.
• Each pair names the intrusive rock and its extrusive twin: granite and rhyolite, gabbro and basalt.

Bowen’s Reaction Series

Minerals crystallize in order as magma cools, from olivine near 1400°C down to quartz near 650°C. The first minerals to crystallize are also the first to weather at the surface.

Sort rocks in Rock Families and follow a path in the rock cycle journey.

This replaces the old properties chart, and it works differently: it is a decision tree you walk from the top, not a table you scan.

The path

1. Start with luster: metallic or nonmetallic.
2. Then hardness, using the Mohs scale printed on page 16: harder or softer than glass (5.5).
3. Then cleavage: how many directions, and at what angles.
4. Then the final clue: streak color, a reaction with acid, a soapy feel, magnetism, or taste.

Practice in the mineral ID lab.

Page 18 decodes everything on a weather map: the station model, wind speed and direction, sky cover, weather symbols, fronts, and pressure coding.

The two tricks worth drilling

• Pressure code. Sea-level pressure is printed in tenths of a millibar with the leading 10 or 9 dropped. Put a decimal before the last digit, then add 10 or 9, whichever lands in the realistic range of about 950 to 1050 mb. The page gives worked examples: 410 is 1041.0 mb and 872 is 987.2 mb.
• Wind. The staff points in the direction the wind is blowing from. Barbs give speed: a half barb is 5 knots, a full barb 10, a pennant 50.

Decode real ones in the station model decoder.

The last three models explain why climates sit where they do. Page 19 has the planetary wind belts and a cross section of the lower atmosphere; page 20 maps the surface ocean currents.

What to take from them

• Air rises at the equator (the Intertropical Convergence Zone), making it wet, and sinks near 30°, making the world’s great deserts.
• New York sits in the belt of prevailing westerlies, which is why weather generally arrives from the west.
• The troposphere holds our weather and thins from the equator toward the poles; the tropopause caps it, and jet streams run along it.
• Warm and cold currents are drawn separately on page 20. The Gulf Stream carries tropical warmth north past New York toward Europe.

Test the factors in the climate lab.