Topic Quiz: Earth and Space Science

Where the answer comes from: the table row for 2018 reads "| 2018 | 85 | 88 | 41,000 |".

Step by step:

1. Find the column "Days with no rain, June–September" and look down it for 88.
2. The value 88 appears in the 2018 row.
3. Move right along the same row to "Acres burned": 41,000.
4. Watch out for 2020 and 2022: they show 88 in a different column (average summer high temperature, °F), not dry days.

The answer is 41,000 acres.

Check: No other year has 88 in the dry-days column (the others are 61, 70, 79, 65 and 92).

Tip: When a number appears in more than one column, say the column name to yourself before you read across.

Where the answer comes from: paragraph 3 defines storm surge as "a rise in sea level pushed ashore by the storm's winds." Paragraph 4 says "Raising homes on stilts or pilings keeps living space above floodwater, and restoring coastal marshes and barrier islands helps absorb some of the surge."

Step by step:

1. Identify the hazard: storm surge is flooding by seawater.
2. Sort the actions in paragraph 4: roof straps and shutters protect against wind; raised homes and restored marshes protect against water.
3. Only one choice combines the water-related actions.

The best plan is to raise homes on pilings and restore the marshes along the shore.

Tip: Match the solution to the specific hazard named in the question. A true statement about a different hazard (wind) is still a wrong answer.

Where the answer comes from: the passage says "All plots had the same soil and the same 4% slope, and all received the same natural rainfall for one year." It also says "each plot got a different winter treatment."

Step by step:

1. Independent variable (changed on purpose): the winter treatment (plowing or not, cover crop or not).
2. Dependent variable (measured): the soil lost.
3. Controlled variables (kept the same): soil type, slope and rainfall.
4. Only one answer choice is a controlled variable: the slope of the land.

The answer is the slope of the land.

Check: If one plot were steeper, water would run off it faster, and that plot might lose more soil for a reason unrelated to its treatment.

Tip: Sort every variable into three bins: changed, measured, kept the same. The controlled variables are the ones that make the test fair.

Where the answer comes from: the passage says Earth's axis is tilted 23.5° and "always points in the same direction in space," and the table shows Northern Hemisphere winter on January 3. The diagram shows that in December the Northern Hemisphere is "tilted away" from the Sun.

Step by step:

1. On January 3 the Northern Hemisphere is tilted away from the Sun, so it has winter.
2. Earth is one solid ball. If the north half tips away, the south half tips toward the Sun.
3. Tipped toward the Sun means a higher noon Sun and longer days, so Australia has summer.
4. Earth happens to be closest to the Sun then, but that is not the reason. The passage's data show distance does not cause seasons.

It is summer in Australia, because the Southern Hemisphere is tilted toward the Sun.

Tip: A choice can have the right fact and the wrong reason. Check both parts.

Where the answer comes from: the passage says that at new moon and full moon "the bulges add together. This gives spring tides, with the highest highs, the lowest lows and the largest tidal range." In the table, the lowest lows were −0.2 m (new moon) and −0.1 m (full moon), while the quarter moons had lows of 0.6 m and 0.7 m.

Step by step:

1. The group needs the lowest low tides.
2. The lowest lows come with spring tides, at new moon and full moon.
3. April 24 is a full moon, so the tides near April 24 should give the lowest lows.
4. About a week earlier is the first quarter moon, which gives neap tides with higher lows.

The best choice is April 24, at the full moon.

Tip: For tide questions, link the phase to the alignment: lined up (new or full) = extreme tides; right angle (quarters) = mild tides.

Where the answer comes from: the passage says ores "form over millions of years, so they are nonrenewable," and that "Recycling does not create new metal, but it lets the same metal be used again, so less new ore must be mined."

Step by step:

1. Aluminum is made from bauxite ore, which takes millions of years to form.
2. A resource is renewable only if nature replaces it on a human time scale. Nature does not replace mined bauxite that fast.
3. Recycling reuses aluminum that was already mined. It slows how fast bauxite is used up, and it saves about 95% of the energy, but it does not create new ore.
4. So the student mixes up recyclable with renewable.

The best response is aluminum is still nonrenewable, because its ore forms over millions of years; recycling only makes the existing supply last longer.

Tip: Renewable = nature makes more quickly. Recyclable = people can reuse what they have. A resource can be recyclable and still nonrenewable.

Where the answer comes from: the passage says "where the water spread into a pool at the bottom end, it slowed down. Gravel settled first, close to where the water entered the pool, and fine sand settled farther out." It defines deposition as "the dropping of sediment when the water, wind or ice slows down."

Step by step:

1. When the river enters the calm lake, the water slows down, just like in the model's pool.
2. Slower water cannot carry heavy particles, so the biggest, heaviest pieces (gravel) drop first, near the river mouth.
3. Smaller pieces (sand) are carried a little farther.
4. The finest particles (mud) stay in the water longest and settle farthest out in the lake.

The answer is gravel near the river mouth, sand farther out, and fine mud farthest into the lake.

Tip: Apply a model by matching its parts to the real case: tray = river, pool = lake. Then use the same cause (slowing water) to predict the effect.

Where the answer comes from: the passage says "Water warms up and cools down more slowly than land, so places near an ocean usually have milder winters and cooler summers than places far inland." It also says the cities are "at the same latitude (41° N) and almost the same elevation."

Step by step:

1. List the climate factors: latitude, elevation, nearness to water, ocean currents.
2. Latitude and elevation are the same for both cities, so they cannot explain a difference.
3. Port Harlow is on the coast; Dunmore is 900 km inland. That factor is different.
4. The ocean warms slowly in summer and cools slowly in winter, keeping Port Harlow's air milder in both seasons. Dunmore heats up and cools down much more.

The best explanation is Port Harlow is next to the ocean, which heats and cools more slowly than land.

Tip: To explain a difference, the cause must itself be different between the two cases. A factor that is the same for both cannot explain why they differ.

Where the answer comes from: the table pairs distance and age: "| W | 160 | 2.0 |", "| X | 320 | 4.0 |", "| Y | 480 | 6.0 |", "| Z | 640 | 8.0 |" (distance in km, age in millions of years).

Step by step:

1. Steady speed means the plate covers the same distance in each equal period of time.
2. Each extra 160 km of distance goes with an extra 2.0 million years of age.
3. So every island gives the same speed: 160 \div 2.0 = 320 \div 4.0 = 480 \div 6.0 = 640 \div 8.0 = 80 km per million years.
4. The heights of the islands tell how much they have sunk and eroded, not how fast the plate moved.

The best support is each additional 160 km of distance matches an additional 2.0 million years of age.

Tip: To support a claim about a rate, choose evidence that uses both quantities in the rate (here, distance and time).