GEOS 170 Exam #3
About what % of world population lives in cities?
(~50%); in US? (~80%)
What are possible causes of mass extinctions? What about the one 65 million years ago (K‐T extinctions) that wiped out the dinosaurs?
Climate change; asteroid impact; massive volcanism, Steroid impact; found it in Gulf of Mexico
Which is denser, cold or warm water?
Cold
Does rising air get wetter (rain) or drier? How about sinking air?
Cold air can hold less moisture so when it rises it becomes more saturated and creates rainclouds while sinking air dries out while it warms.
Why are the poles considered deserts?
Cold air doesn't hold much water, so cold places tend to be very dry - also descending air
Which water sinks to the bottom, cold and salty or warm and fresh?
Cold and salty
How does ocean water temperature cause deserts?
Cold water reduces evaporation and humidity and rainfall
Where do we find carbon on earth?
Everywhere
Where do ocean gyres transport heat to?
From equator toward the poles in both hemispheres
How is global warming different from the greenhouse effect?
Greenhouse always existed, warming is caused by increasing greenhouse gases in the atmosphere
What effects energy going out?
Greenhouse gases
Does visible light/energy come in or out from the sun?
In
Where is carbon mostly stored?
In the ocean
Which kinds of radiation are affected by greenhouse gases? Which are not?
Infrared (heat energy) is, but visible light is not.
Why do we need the ozone?
It blocks ultraviolet radiation from reaching the surface which is a good thing.
How is biodiversity (# of species) affected by a mass extinction? How long does it take for biodiversity to recover? Does everyone lose in a mass extinction?
It decreases and takes up to 100 million years to recover. Not everyone loses in a mass extinction, mammals rapidly evolved when dinosaurs wiped out
How is the CO2 in the atmosphere changing?
It is increasing
Where does air rise and where does it sink?
It rises at the equator or 60 degrees. It sinks at the poles or 30 degrees.
How would the difference between summer and winter temperatures change if the Earth's orbit around the sun were more elliptical?
It would increase
Is the greenhouse effect natural or man made? What temperature does it keep the earth's surface at?
It's natural. It keeps the earth 60 degrees warmer than it would without an atmosphere.
What causes the ozone hole?
Man-made chlorofluorocarbons (CFC) in the stratosphere
How are sea level and ice volume on land related?
More ice means lower sea level
Where does ozone live? Why is it helpful in this layer? Is ozone always helpful to us?
Mostly lives in the stratosphere. It's helpful in the stratosphere because it helps protect life from UV. It isn't always helpful to us because near the ground it is a pollutant.
Troposphere
The bottom layer, 10 km thick, weather occurs here
Why does tilt cause seasons?
The hemisphere tilted toward the sun gets a more direct hit from the sun's energy and thus more solar energy. Also, the hemisphere tilted toward the sun has longer hours of sunlight. Thus, the hemisphere tilted toward sun get summer
How long have we been in an Ice Age and what's different between glacial and interglacial periods?
The last 2 million years, glacial periods are colder.
What causes seasons?
The tilt of the earth's rotation axis
What are postulates of evolution?
There is genetic variation in a population; Certain traits or characteristics are genetically determined, passed from parent to offspring; More individuals are born than can survive, due to limited resources; and Advantageous traits help survival, and are therefore passed on to more offspring
How do glaciers tell us about global warming?
They are retreating due to increased melting everywhere
Why is the atmosphere not too thick or too thin for life?
Thin=no heat and can't breathe Thick=too much pressure, too much heat
Mesosphere
Third layer
Why is there a Coriolis force and how does it deflect moving objects?
This force is because the earth is round and spinning. It deflects moving objects to the right in the northern hemisphere and to the left in the southern.
What small changes in Earth's orbit around the sun account for enough variation in solar energy received on Earth to move from glacial (cold) to interglacial (warm) parts of an Ice Age?
Tilt; eccentricity (how elliptical the orbit is); precession (wobbling of rotation axis)
Thermosphere
Top layer
True or false: the majority of all species that have ever existed are now extinct.
True; by some estimates 1000 species have gone extinct for every one alive today
What kind of radiation does ozone interact with?
UV only and not visible or infrared
Other atmospheres
Venus has VERY thick, mostly CO2 atmosphere so HUGE greenhouse effect. Mars has VERY thin, mostly CO2 atmosphere but practically NO greenhouse effect
What is the difference between weather and climate?
Weather changes rapidly, climate changes slowly.
How do the surface currents (gyres) flow?
With the wind, and turned by the coriolis force and running into land. Clockwise in the northern hemisphere and counter clockwise in the southern hemisphere
Is CO2 natural and are humans causing a change in the CO2 found in the air?
Yes and yes
Is it possible that we are in a mass extinction now?
Yes; role of humans lead some to call this the Anthropocene
What are other alternative energy sources, and current contribution to US energy?
hydroelectric, ~7%; wind, ~3.5%, solar, ~0.1%, biofuels, 1.4%, geothermal, 0.4%
What are the main wind belts on Earth?
-Trade winds: (come from the east) and from 30 degrees south to 30 degrees north. -Mid-latitude westerlis: (come from the west) and are 30-60 degrees in both hemispheres
What are the 6 processes that remove CO2 from the atmosphere?
1. Breathing 2. Rotting vegetation 3. Burning of fossil fuels 4. Volcanic eruptions 5. Forest fires 6. Exchange with the ocean
What level does the UN expect world population to reach its carrying capacity and stop growing?
10 billion
What is the molecule ozone formed from and where is it mostly found?
3 atoms of oxygen, mostly found in the stratosphere
How salty is sea water?
3.5%
About what % of world's population lives within 100km of a coast?
40%
How deep is the ocean on average?
4000m (13,000 ft)
How many mass extinctions have happened in Earth's history?
5
What's the world population today? What are the populations of the two most populated countries (China and India)? Are any of largest 15 cities worldwide in the US?
7 million 1.2 billion No, New York is number 17.
How much of all the water is in the ocean? How much of the earth's surface is covered with water?
97% 70%
What's a good definition of evolution?
A description, based on multiple forms of evidence, of the processes that drive change in living systems/populations over time.
What is the ozone layer like?
An umbrella, protecting us from harmful UV rays.
What is the ozone hole?
Area of low ozone formed over Antarctica every spring since 1979
What does the ozone near the ground cause to humans?
Asthma
What are the 5 main ocean basins?
Atlantic, Pacific, Indian, Arctic and Southern
How do greenhouse gases affect the temperature of the earth?
By absorbing heat emitted by the surface and then re-radiating it, so energy stays in atmosphere longer and warms the atmosphere
Which gases are needed in the atmosphere by living things?
CO2 for plants and O2 for animals
Which gases in the atmosphere are greenhouse gases? Which aren't?
CO2, methane, water, CFCs are greenhouse gases Nitrogen and O2 aren't
Where does water sink to the bottom, near the equator or near the poles?
Near the poles
Which gases were early in the atmosphere and which weren't?
Nitrogen, CO2, and water occurred first and oxygen didn't come until later.
What are the main gases that make up the earth's atmosphere and what percentage do they take up?
Nitrogen: 78% Oxygen: 21% CO2: barely anything 0.04% or 400 ppm
Does CO2 affect the ozone hole?
No
Does ozone or the ozone hole cause global warming?
No
Is any energy source perfect and are some better than others?
No energy source is perfect but yes, some are better than others. It depends on lots of things, like access to water, sunshine, few people around, etc.
Do seasons have anything to do with the distance that earth is from the sun?
No! The northern hemisphere is closest to the sun in January
If ice in the ocean melts, does sea level rise?
No; only ice melted on land that then runs to the ocean will raise sea level
What's the main alternative energy source? About what % of US energy is supplied by nuclear? What's wrong with nuclear?
Nuclear; (~20%) or globally (~16%); no storage plan for waste; rarely fails, but when it does, it does so spectacularly, long time from idea to functional power plant (up to 20 years)
What are the main fossil fuels? About what % of US energy is supplied by fossil fuels? Why are fossil fuels such a large part of US/world energy? What's wrong with fossil fuels.
Oil, natural gas, and coal; 70%; Relatively inexpensive; lots of existing infrastructure; They return CO2 to atmosphere, now at 400 ppm, the highest levels in at least the last 800,000 years, and CO2 correlates with global temperatures
Does infrared light/energy come in or out from the earth?
Out
What is the relationship between life on earth and the history of breathable oxygen?
Oxygen is a biproduct of photosynthesis so there is essentially no relationship between the two because plants created it all.
Does evolution happen to individuals or populations?
Populations; in biological sense individuals don't evolve ... some survive and reproduce better
Which is denser, salty water or fresh water?
Salty
Stratosphere
Second layer, 40 km thick, ozone layer
Do deserts form under rising air or sinking air?
Sinking (and therefore drying air)
What does "fittest" mean in evolution?
Strictly - reproductive success; or best adapted to one's environment; fittest isn't biggest, strongest, smartest unless these traits increase reproductive success
What is the net effect of greenhouse gases?
Sunlight comes through easily, but heat energy escapes slowly, making the planet warmer
What determines the density of sea water?
Temperature and salinity, hence thermohaline circulation
How does the atmosphere protect the earth and what from?
The atmosphere is the bubble of gases that surrounds the planet. It protects the earth from rocks (meteorites) and harmful UV radiation.
What determines the length of a glacier?
The balance between snowfall (accumulation) at the top and the rate of melting at the bottom
What things affect energy coming in?
sun output, albedo (reflectiveness) of the Earth, distance of earth from sun