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Oceanography Study Guide:
red=NEED to know
(The first 10 pages of this study guide are all the answers from Prelims 1 + 2) 1/3 of the Final will be questions from Prelims 1 & 2
Prelim 1:
It’s been roughly 15 billion years since the big bang
Our Solar system formed about 4.6 billion years ago
Stars form when cold hydrogen and helium (and sometimes other heavy elements) condense under gravity to form very large masses that generate great internal pressure and temperatures ignite thermonuclear fusion to produce, among other things, visible light and heat energy.
The carbon atoms in your body were originally formed inside a star! ^YOU ARE MADE OF STARDUST!!
How the Moon was formed:
A giant, Mars-sized asteroid knocked into Earth, giving it the 23 degree axis is has today
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Global Warming is the Earth’s mid-life crisis. Right now the Earth is about 4 billion years old and has roughly 4 billion years of life left. The sun will burn out after about 4 billion more years and then, before dying, its outer layer will expand beyond the orbit of the earth and completely incinerate the earth back to dust.
Don't forget about the age old question of make me o lord thy spinning wheel complete
If you were on a boat at 10N and 30W,
you would be in the Atlantic Ocean.
around
here
Latitude is the degree from the equator
to any given lateral line
(with the globe center as the center point)
Longitude is the degree from the prime meridian (London) to any given vertical line (with the globe center as the center point)
The earliest known fossil is aChemical fossil We also discuss several other topics like uconn psych
Life on earth transitioned from being
just simple prokaryotic organisms in the ocean to more complex eukaryotic organisms about 2 billion years ago.
The Cambrian Explosion occurred about 550 million years ago.
Mammals began to rise to greater prominence/became the dominant large animals on earth 65 million years ago (after the meteor).
Mass extinctions:
• typically clear niche space and allow previously minor groups of organisms to fill the space and become prominent components of the global biota (just like 65 million years ago)
• there have been 5 mass extinction events in the geologic past • humanity is now powerful enough to cause a mass extinction event If you want to learn more check out nsg 320 class notes
Earth’s outer crust is thin, rigid, and floats on higher density mantle
The symmetric banding of magnetic anomalies as you move away from a mid ocean ridge axis is really a proxy for the symmetrical increase in age of ocean crust as you move away from the ridge axis.
^Magnetic anomalies are a proxy measure of geologic time - each anomaly can be assigned a specific geologic date. (proves to us that new crust is formed from the bottom and spreads out to the sides.) We also discuss several other topics like whimmm
Continents will continue to move and will eventually all collide again to form a new super continent. [When continents repeatedly break apart and collide together, it’s known as the Wilson Rock Cycle. (Pangaea to individual continents to Pangaea again).]
1. Divergent Boundary (when plates move apart)
????continent-continent
????ocean-ocean
examples include: Mid-Atlantic Ridge and the Red Sea.
When ocean crust collides with continental crust, the ocean crust slides underneath because it’s only slightly lighter than the mantle, while the continents are much lighter than mantle.
An example of ocean crust colliding with an
ocean crust is the Japanese Islands.
When India collided with Eurasia, it did not
slip back down into the mantle because the If you want to learn more check out ori rodriguez
continental crust of the Indian Continent is
too buoyant to sink into the mantle.
Ocean sediment cores can record these Earth processes over millions of years: • Ocean Temperature
• Ocean Productivity
• Large Volcanic Events
• Ice Ages and Iceberg Formation
Siliceous and Calcerous oozes are typically found in biologically productive open-ocean regions.
Scientists obtained information about past ocean temperatures from sediment cores using chemical isotope ratios of the fossil shells.
A wave crest moving across the ocean surface is an important mechanism by which energy is propagated across large distances (not mass!!)
A bunch of waves with a 25-meter wavelength (deep) and a bunch of waves with a 1-meter wavelength (shallow) propagate southward out from under a big storm system in the Gulf of Alaska. The 25-meter wave will reach Hawaii first!
Wave energy gets focused on the headland and spreads out in an embayment as it approaches a coastline.
There are strong laws and regulations against building rock walls/jetties that extend outward from a beach and into the ocean on someone’s private property because it could block longshore transport of sand and shrink an adjacent property owner’s beach.
If you’re ever caught in a rip current, swim parallel to shore for 10-20 meters. Then swim back to shore and call Bruce!!!
Wind Speed sets the maximum upper limit on
ocean wave height.
The definition of wind fetch = the unobstructed
distance over which the wind blows
Oceanographers decide that a tsunami has been
generated by the detection of a passing tsunami wave using moored buoys that are fitted with bottom pressure sensors and can detect small change in sea-surface height as the tsunami wave passes overhead
If you ignored a tsunami warning and went to the beach you would be a sad, stupid, and pathetic idiot
Other than gravity, the centrifugal force is the other key player involved with the creation of the two tidal bulges that make up the tides.
If you went down to the beach on Saturday at 5:00am to dig clams at low tide, in order to catch the same low tide to dig more clams, you would need to go down to the beach on Sunday at 5:50am. Remember, the tide is 50 min slower.
To get all three daily tidal patterns (diurnal, semi-diurnal, and mixed semi diurnal) on earth you need two tidal bulges and a lunar orbit at 28 degrees from the equator.
If you are on the beach and the moon is full, then the tide range is exceptionally large.
We get rotary tides because the continents block the propagation of the tidal wave and the Coriolis force acts on the tidal wave.
There is almost zero tidal range in Hawaii because it is near an amphodromic point.
There is an exceptionally large tidal range in the Bay of Fundy because tidal forcing is at resonant frequency for the bay’s length.
The Westerlies are a global surface wind pattern that is contained within the 30-60 degree latitude band.
The pattern of atmospheric pressure at sea level (sea level pressure) that alternates with latitude between low and high levels and the Coriolis force both are needed to explain the three main wind bands on Earth.
The ocean’s mixing depth is shallower in the summer because warm surface waters in summer are very buoyant and buoyant surface waters cannot be mixed downward very easily by the wind. Remember the beach ball analogy Bruce used.
The Ekman Transport is the movement of a relatively thin slab of ocean surface water (50-100meters deep) in response to wind forcing. This slab moves exactly to the right or left of the direction of the wind in the northern or southern hemisphere, respectively.
Fully developed Geostrophic Currents move along lines of constant pressure.
The mound of surface water in the middle of a subtropical gyre is formed by Trade Winds and the Westerly winds that drive the Ekman Layer towards the center of the subtropical gyre.
When the surface waters mound up in the center of the subtropical gyre in the northern hemisphere, it creates a center of pressure under the mounded water. The response of the water below the mound is to move out away from the high pressure at first, but then to turn until it moves along lines of constant pressure in a clockwise direction around the center of high pressure.
Vertical upwelling of deep water along the Equator is caused by divergence of the Ekman Layer that is driven by the trade winds.
If the wind is blowing from the south along the west coast of the USA, then the Ekman Layer would move onshore.
The main water masses in the ocean interior are identified based on temperature and salinity signatures.
The speeds of deep currents are determined by measuring the rate of decrease in the abundance of 14C (a radioactive form of carbon) in deep-ocean seawater.
It takes about 2000 years for deep ocean water that sinks in the north Atlantic to make its way down around the Southern Ocean and up into the deep north Pacific.
Oceanographers care so much about the conveyor belt circulation because it moves a lot of heat away from the equator to higher latitudes to moderate temperatures at both low and high latitudes. (contributes to melting of the polar ice caps)
Prelim 2:
Net Primary Production is the difference between CO2 gained through photosynthesis and CO2 lost through respiration.
The compensation light level refers to the light level where photosynthesis and respiration are equal.
Nitrogen, phosphorous, silica, and iron are the principle nutrients studied by oceanographers because they are the elements that, from time to time, can be in short supply and limit the growth of phytoplankton.
Subtropical gyres have low levels of primary production per square meter because there is a persistent lens of warm low-nutrient surface water that depresses the thermocline and associated nutricline.
Trade winds that force the Ekman Layer divergence in combination with a relatively shallower thermocline in the eastern equatorial Pacific (off Peru) causes primary production along the equator to be high in the eastern equatorial Pacific and low in the western equatorial Pacific.
Enhanced tidal mixing over shallow continental shelf regions account for year-round high levels of primary production in coastal regions.
The Critical Depth= depth to which phytoplankton can mix whereby the time they spend below the compensation depth losing carbon just balances the time they spend above the compensation depth gaining carbon and resulting in net primary production over the course of the day being zero.
50% of the oxygen you breathe each day comes from the ocean. Aka, 50% of global primary production takes place in the ocean.
To make sense of all organisms that make up pelagic communities, oceanographers classify organisms into broad groups based on: • Autotrophic
• Heterotrophic
• Body size
Exploitation Efficiency of the copepod community that has just come out of winter diapaus (hibernation) at the start of the North Atlantic spring phytoplankton bloom is expected to be low
Question:
Main reason coastal upwelling regions have much higher amounts of harvestable fish production each year is because of….
• Close to fishing port cities and are therefore efficiently harvested • Have largest number of trophic steps between primary production + harvestable fish
• Upwelled waters are colder so fish mature more slowly and thus grow larger before reaching adulthood
• NONE OF THE ABOVE
Walker Circulation Cell in transition from normal to El Nino conditions slows down or reverses
The Cold Tongue (cold sea surface temperature along the equator) becomes less cold and shrinks back towards Peru in the eastern Pacific during El Nino conditions.
Global average temperature during an El Nino year rises pretty dramatically.
The effects of El Nino conditions in the Pacific can be transmitted to the far reaches of the globe by variation in the position of the Jet Stream in the atmosphere.
A pelagic environment that has naturally very low plant nutrient is called Oligotrophic and can be found in vast subtropical gyres.
Growth requirements for heterotrophic bacteria ???? need dissolved organic matter.
Prochlorococcus is the main contributor to primary production in open-ocean oligotrophic environments. It’s also a type of autotrophic bacteria.
Biological Carbon Pump is at its most efficient in Eutrophic conditions (high nutrient conditions).
As a general rule, carbon is found to be efficiently recycled in a given pelagic ecosystem, nitrogen is also efficiently recycled.
Competition with other species or predation by other species typically sets the lower limit in the vertical elevation of a given species living in the rocky intertidal.
Some sort of intermediate physical disturbance such as a drift log smashing on the rocks, or big storm waves crashing on the rocks, wipes the rock clean and restarts the whole process of competition among all species. This prevents single rocky intertidal species from eventually out-competing all other species and becoming the only species in the rocky intertidal.
Exceptionally warm coastal waters is an underlying environmental factor thought to be causing the massive starfish die-off from Alaska to Baja California.
Kelp forest declines when sea otters are removed.
60-90% of coral’s overall nutrition comes from their Zooxanthellae symbionts.
Coral bleaching occurs as a result of the breakdown in symbiotic relationship between the coral and its Zooxanthellae.
Coral bleaching begins when normal ocean temperatures are increased by about 1oC for a few weeks.
A wolf comes closest to representing the earliest form of whale (Pakicetus).
Whale vocalizations can be used for:
• Prey detection
• Communication
• Sexual selection
• Navigation
A bar of written music is a reasonable analogy for a Spectogram that whale researchers use to visualize the pattern of whale vocalization.
Professor Christopher Clark thinks ambient noise from commercial ship traffic may be the greatest threat to whale population survival.
Norway, Iceland, and Japan are currently hunting whales in large numbers. Viruses can often play a positive role in pelagic ecosystems.
Viruses vary as a fixed proportion of the abundance of bacteria so they are high near the ocean surface and low at great depth.
In order for a viral infection to propagate, the host must be highly abundant (i.e. during a large phytoplankton bloom) and the viruses must be in high abundance in order to overcome the high probability of viral decay due to destructive enzymes in seawater.
Professor Ian Hewson recently discovered the type of virus that is causing the die-off of starfish along the west coast of the USA.
H-bonds and Thermal-Kinetic Energy are the two opposing forces/energies that determine the three phases of water (solid, liquid, and gas).
If you added an equal amount of heat energy to the ocean, atmosphere, and land, the ocean would experience the smallest temperature change.
93% if excess heat that accumulates in the earth system as a result of human-caused greenhouse gas emissions has been taken up by the ocean.
When winds blow over the surface ocean to cause evaporative cooling, the heat that leaves the ocean surface is then transferred from the ocean to the atmosphere as latent heat in the form of atmospheric water vapor.
If you have 1000-gram sample of seawater that has a salinity of 34%o, and you boiled away all of the water, 34 grams would still remain. (34/1000)
The surface ocean salinity is typically the highest in the subtropical gyres.
Conveyor belt circulation explains, in part, why nitrate and phosphate concentrations in the deep oceans are low in the deep North Atlantic and high in the deep North Pacific.
Oxygen concentration reaches a minimum level just below the sunlit layer (euphotic zone) of the ocean because microbial respiration fueled by dead organic material raining down from above consumes oxygen down to low levels.
The concentration of oxygen will decline in response to global warming n the oxygen minimum zone.
CO2 is high in the deep ocean because microbial consumption of organic matter and associated respiration produces CO2.
CO2 would diffuse out of the ocean if deep water were brought up to the surface an into contact with the atmosphere.
The ocean has taken up about 30% of the total CO2 emitted by fossil carbon emissions since the star of the industrial era.
Coral reef growth will begin to decline/stop and polar seas will be corrosive to calcium carbonate shells of marine plankton within a matter of decades as a result of ocean acidification.
Unit 3: Climate Change
2/3 of the Final will be questions on this material
To figure out if an organism is Autotrophic or Heterotrophic, simply ask whether or not it has chlorophyll. Yes???? autotroph. No???? heterotroph.
Two major types of Methane:
• Methane formed in rock
formations over
geological time frame
• Methane formed by
decomposition of organic
matter by bacteria in
absence of oxygen
DANGEROUS TIPPING POINT IS ONLY 15-30 YEARS IN THE FUTURE!
Controlling methane is critical to the solution!!
Climate is stable to a point, but rapid, radical change can tip it over the edge!
Natural gas is not the solution!
Natural gas is mostly methane.
Methane is much more potent greenhouse gas than carbon dioxide, so even small emissions matter.
When it comes to ocean pollution, Nitrogen and Phosphorus are both detrimental to aquatic ecosystems. Phosphorus is a bigger problem in freshwater lakes.
summary:
P is major cause of eutrophication in lakes
N is major cause of eutrophication in coastal marine ecosystems
Critical N:P ratio for needs of phytoplankton = 16:1 (Redfield ratio)
Climate influences N pollution from the landscape – wetter climates deliver more nitrogen pollution to the coast. Climate also influences the sensitivity of coastal ecosystems to N pollution.
Dead zone= great lakes
Pasta > Burgers
Summary:
Coastal nutrient pollution
(particularly nitrogen) is a
severe problem. Nitrogen
comes from many sources,
but agriculture dominates
globally.
Technical solutions exist, including some that are relatively inexpensive. Policy considerations of diet (meat, overconsumption) and energy (liquid biofuels!) are critical.
High quality science is essential to understanding and solving the problem.
Coral bleaching is loss of symbiotic algae usually from heat stress Most of corals’ food comes from photosynthesis
Because of this, Elkhorn coral, once the commonest coral in the Caribbean, has now been added to the endangered species list!
• El Nino 2015-16 is already a big warming event
• Coral bleaching and disease will increase with this event, thus endangering sustainability of these ecosystems
• Other surprising outbreaks, like the sea star epidemic, might also increase
Two fundamental types of Geoengineering:
1. Solar Radiation Management (SRM) - Altering the Earth's radiation budget to affect temperatures directly; a climate intervention approach. 2. Carbon Dioxide Reduction (CDR) - extracting CO2 from atmosphere and storing it elsewhere; a CO2 remediation approach.
Carbon Dioxide Reduction:
Carbon dioxide reduction refers to the
extraction of carbon dioxide from the
atmosphere and its long-term storage
underground, in the ocean, in the
terrestrial biosphere, or in the built
environment.
LOL no
2014-warmest
year in global
record.
2000-2010 -
warmest
decade in
global record.
2012 - warmest
year in the US
record.
2015 - on track
for warmest
year in global
record.
Warming in the Pipeline: Ocean has absorbed most of the heat from greenhouse warming over the past 50 years, and as it equilibrates with the atmosphere, the atmosphere’s temperature will rise.
“Hurricane” (Superstorm)
Sandy was a hybrid storm
formed from convergence
of tropical hurricane and
extra-tropical storm
systems.
^Changed the politics of
global climate change;
politicians were once again
willing to talk about it.
Sustainable Development
Definition:
Development that meets
the needs of the present
generation without
compromising the ability
of future generations to meet their own needs.
Review of Unit 3:
The ecological footprint expresses how much of nature's renewable
bioproductive capacity is currently being appropriated.
SO if the ecological footprint (area) resulting from consumption by the entire global population exceeds the actual area of the planet, then we are withdrawing more from earth than earth can replenish…
The UN estimates that humanity’s total Ecological Footprint is now 1.6 planet Earths. UN scenarios also show that if our current consumption trends continue, by 2030 we’ll need two Earths to support humanity.
Human Population Growth We reached 7-billion in 2011 and we are expected to add another billion by 2024!
Sea level rise since Industrial Era:
IPCC* 5 report that came out about a year ago has placed the expected rise to 1 meter above pre-industrial level by the end of this century…
Many scientists now think the arctic summers will be completely ice-free by 2030!
1. With business as usual rates of CO2 emissions ocean acidity will increase by 170% by the end of the century
2. Within decades polar oceans will be corrosive to unprotected calcareous shells of marine organisms
3. Within decades tropical coral reef growth will be hampered or stopped altogether.
4. The far-reaching effects of ocean acidification are predicted to impact food webs
5. People who rely on the ocean’s ecosystem services are especially vulnerable and may need to adapt or cope with ocean acidification impacts within decades.
We have 500 Gt (1015 grams) of CO2 remaining while still keeping the planet surpassing the 2 oC warming above the pre-industrial level that is thought to be “safe”.
We have two options:
1. Keep emitting at 50 Gt per year for 20 years (if the oceans and land takes up 50%) and then go instantly to zero?
2. Slow down emissions starting now and make the 500 Gt last a bit longer while we switch to a zero carbon emission society.
The Millennium Ecosystem
Assessment Report, 2005:
It provides an assessment on the
state of the planet's health. It
was five years in the making. It
was put together by about 390
experts and peer-reviewed by an
additional 1000 experts.
The bottomline is that solving
the global emissions problem
MUST address the emission of
China and India for the climate
change issue will be solved.
“Copernicus Transformation” ???? the idea of convincing humans that they are not separate from nature (not the center of the universe), but rather just one part of nature does not seem too far fetched to me
There are about 20 slides just telling you that YOU can make a difference, so don’t forget that!!
Good luck!!