Comprehensive Fall 2024 Science Exam Flashcards: Astronomy, Geology, Oceanography, and Climate

Q1: Which is true about star formation?

A: b) Stars formed about 500 million years after the Big Bang when cold hydrogen gas condensed into large masses due to gravity, leading to nuclear fusion.

Q2: Where did the heavy elements in your body (e.g., carbon, nitrogen) originate?

A: c) 100% created in stars or when stars exploded.

Q3: How do we know the sun is made from a previously exploded star?

A: c) The sun is composed of hydrogen along with heavier elements.

Q4: How was the moon formed?

A: d) A Mars-sized object hit the Earth, and the ejected material coalesced into the moon.

Q5: If Earth were scaled to a 0.5 m beach ball, how thick would the ocean be?

A: b) 0.15 millimeters.

Q6: At 10°S, 20°W, which ocean are you in?

A: a) Atlantic.

Q7: Which is true about Earth's rigid outer crust?

A: d) Floats on top of the mantle like a cork on water.

Q8: What evidence led Alfred Wegener to continental drift?

A: c) Fossil and mineral belts on different continents aligned when moved together.

Q9: Why is symmetric magnetic banding evidence for seafloor spreading?

A: b) Anomalies show crust is symmetrically older away from ridges.

Q10: How are continents moved around on Earth?

A: b) Whole tectonic plates containing continents move.

Can a tectonic plate be both continental and oceanic crust?

Yes

What is the driving mechanism for plate tectonic motion?

Both b and c (Mantle convection and Slab pull)

Are divergent boundaries only found at mid-ocean ridges?

No

Where is ocean crust colliding with ocean crust?

Aleutian Islands (Alaska)

Why didn't India sink during collision with Eurasia?

Too buoyant to sink.

How were the Hawaiian Islands created?

Mantle hot spot upwelled magma to surface, forming islands.

What kind of history is preserved in marine sediments?

All of the above (Past climate change, Past biological productivity, Past volcanic activity, Past extinction events)

Can isotope ratios in shells reveal past ocean temperatures?

True

How many mass extinctions have occurred (including today)?

6

What triggered the Cambrian Explosion?

Snowball Earth + genetic innovations.

Which geologic period is represented by Ithaca rocks?

Devonian

Where did atmospheric oxygen come from?

Bacterial photosynthesis

What drove increases in large predators during the Mesozoic Marine Revolution?

More dissolved oxygen

Where can we trace the origin of backbones?

Fish

*************** on a beach and watch a set of large waves of similar wavelength coming ashore. What does this tell you about the storm that created them?

Storm occurred far away from the beach.

Why is wave energy focused on a headland and dispersed in a bay?

Wave refraction

If caught in a rip current, what should you do?

Swim 10-20 m along the shore, then back.

Factors determining wave height

Wind speed, duration, and fetch.

Tsunami wave propagation speed

~500 mph (jetliner).

Difficulty in predicting tsunami wave height

Bottom depth affects height and we lack detailed seafloor maps.

Force creating the 2nd tidal bulge

Centrifugal force.

Location of semi-diurnal tides

Mid-latitude.

Occurrence of Spring Tides

During a Full Moon.

Cause of rotary tides

Coriolis + blocking by continents.

Tidal range near an Amphidromic Point

Small.

Air column producing lower pressure at sea level

Air with water vapor.

Direction of Trade Winds

Low pressure at equator, high at 30° → winds move high to low, deflected by Coriolis.

Surface mixing depth in temperate regions during fall/winter cooling

Deeper.

Ekman Transport

Horizontal transport of thin slab of surface water due to wind.

Coastal upwelling with strong south-to-north winds along the U.S. west coast

Yes.

Cause of subtropical gyres rotation

Winds pile water into center → high pressure → outward flow turned by Coriolis.

Identification of deep-water masses

Temperature and salinity.

Time for deep water to move from North Atlantic to North Pacific

2000 years.

Effect of Meridional Overturning Circulation collapse

Decreases equator-to-pole heat transport.

Status of Atlantic Meridional Overturning Circulation

Yes.

Walker Circulation Cell

East-West across the Pacific.

Trade winds behavior during El Niño

Reverse direction.

Reason for decreased primary production off Peru during El Niño

Thermocline deepens off Peru.

Global reach of El Niño effects

Variation in Jet Stream position.

Global average temperature during El Niño years

Increases.