Oceanography Midterm #1 – Flashcards

question
What is special about the Sargasso Sea?
answer
It is defined by the surrounding ocean currents
question
List Four Reasons to Care about the Ocean
answer
Lots of life (50% species), produces 70% of O2, 71% of Earth's surface, major source (20% animal protein)
question
Compare Ocean depths to land heights
answer
ocean is 4.5 times greater than average land elevation
question
what percent of Earth is covered with water?
answer
97%
question
What percent of Earth's water is found in the ocean
answer
71%
question
Compare and contrast the following (hypothesis, theory, law, fact)
answer
Hypothesis: Tentative explanations proposed Theory: Patterns emerge. If one or more of the relationships hold the hypothesis becomes a theory Law: Theories that evolve into larger constructs Facts: Law and theory can be statements of fact
question
The ocean compromises what percent of Earth's mass?
answer
0.02%
question
Largest animal to ever inhibit Earth. What does it eat?
answer
Blue Whale. Eats up to 40 million krill a day
question
Why do waves break as they come ashore?
answer
Water is slowed by contact with the sea bed while the top of the wave is still moving fast so it rolls over and breaks
question
Why is there so much life around volcanic islands (seamounts)?
answer
There's lots of nutrients because the deep ocean currents collide with the islands flanks
question
What do tuna eat and what eats them?
answer
Tuna eat plankton feeders and sharks eat tuna
question
Why do hammerhead sharks come to seamounts?
answer
The locals of the seamounts provide a cleaning service
question
what do sardines eat and what four organisms eat them?
answer
Sardines eat plankton and cape gullets, sharks (bronze whaler), dolphins, and whales eat them
question
Where do we find some of the roughest conditions? What does this do to the ocean productivity?
answer
Roughest conditions found near (south Atlantic) poles. it enriches the surface waters (food in abundance)
question
Basis of all life in the ocean?
answer
fighter plankton
question
largest migration of life on the planet. explain.
answer
Disappearance of the sun triggers 1,000 million tons of sea creatures searching for food near the surface (graze on fighter plankton)
question
Why do sea turtles lay their eggs on the same day?
answer
so predators on the beach are overwhelmed so many babies get to the water
question
why do herring go into shallow water?
answer
to breed
question
why do grey whales migrate such great distances?
answer
seeking the krill that came to feed off the herring eggs
question
how do killer whales kill a grey whale calf?
answer
they force themselves between mother and calf then leap onto it and push it under (drown it) and kill it
question
what is special about the North Star (Polaris) and why was it so important in early navigation?
answer
It doesn't move so you can refer to it for navigation
question
Where did the Cook voyages go and what were their contributions?
answer
Went to South Pacific. They found data on ocean depths, wind directions, water temperatures, and surface currents
question
What was the echo sounder and why was this important to oceanography?
answer
It allowed measurements of seafloor bathymetry
question
Satellites are being used more and more to sturdy the oceans- why are they so valuable?
answer
They gather large scale data over short time periods
question
What prompted colonization of Polynesia and Viking exploration
answer
economic reasons
question
why did the Chinese set out in the 1400's to launch "the greatest fleet the world had ever known"?
answer
To explore the other side of the world and convince nations China was the only civilized state
question
Why is meant by "reverse tribute"?
answer
Giving things to people to show their wealth
question
Who discovered North America?
answer
Vikings
question
What research question was the focus of the Glomar Challenge?
answer
To test a controversial hypothesis about the history of the ocean floor
question
When did oceanographic institutions get established and why?
answer
they evolved to ensure continuity of effort when demands became greater than any single voyages capability
question
Describe the initial surface of the Earth
answer
Sandy with lots of craters from collision
question
How and when did the moon form?
answer
3.9 billion years ago. Molten debris coalesced together after collision with something the size of Mars
question
"habital" zone
answer
right distance from the sun so the oceans don't boil away/ freeze
question
where did the water come from the eventually filled the oceans?
answer
Commets showered earth with water
question
What is a thermophile?
answer
Organisms that can live in extreme environments
question
Whats the oxygen revolution? what caused it?
answer
Photosynthetic organisms producing enough oxygen to oxidize minerals dissolved in ocean and surface sediments
question
what's the magnetic field do and how has it influenced how Earth developed?
answer
Magnetic field deflects solar wind and preserves our air
question
how do we think the planets formed and why do we have rocky and gases planets?
answer
Planets formed from space debris gravitating and being held together. We have rocky and gaseous planets because of their distance from the sun and solar winds
question
Three sources of hear that caused early earth to be molten?
answer
Frictional heating, impacts, radioactive decay
question
How does the composition of the crust differ from the whole-earth composition?
answer
The crust composition has light elements up and heavy elements down
question
Compare and contrast the lithosphere and asthenosphere
answer
Lithosphere: cool, outer layer, 70-200km, composed of continental/oceanic crusts and uppermost portion of mantle Asthenosphere: hot, partially melted, slowly flowing layer of upper mantle, 350-650km
question
Three types of plate boundaries and what occurs at each
answer
Divergent: spreading centers, new crust Convergent: sudbuction, crust destroyed Fault: sliding, lithosphere breaks
question
How old are the oldest ocean rocks- why so young?
answer
Less than 200 million years old because sediments are conducted at a plates leading edge
question
Greatest objections to Wegner's hypothesis?
answer
That he only selected data supporting his hypothesis, ignoring contrary evidence
question
Why is the Earth's interior still hot?
answer
Radioactive elements within Earth's core and mantle continue to decay and produce heat
question
What is a volcanic island arc? Where do they form?
answer
Curving chains of volcanic islands/ seamounts that occurs parallel to concave edges of trenches
question
Would the most violent earthquakes be associated with spreading centers or subduction zones? why?
answer
Subduction zones because there was no evidence of new crust spreading centers must be balanced by destruction the crust plunges into the mantle(subduction zones are deeper and more violent)
question
What's a hot spot and how can they be used to determine plate motion and rate?
answer
Plumes of magma rising from stationary sources of heat in the mantle
question
Why are tectonic terranes and how do they form?
answer
Isolated part of seafloor, island arc, plateau, continental crust, or sediment brought by seafloor spreading to a position adjacent to a larger continental mass
question
What does magnetic field do for us?
answer
It's a force field that protects us from space weather and radiation
question
how can ancient pottery be used to help us understand the magnetic field?
answer
Pottery records the Earth's magnetic field when it goes into the film. We know the rate of change in the magnetic field has been up and down but the last 300 years there has been a rapid fall
question
What would happen if the liquid core stopped moved?
answer
the dynamo would shut down
question
How fast is Earth's core cooling?
answer
100 degrees per billion years
question
How often have magnetic field reversals take place?
answer
Once every 200,000 years
question
What has happened in the South Atlantic?
answer
Magnetic anomalies have begun under the ocean (reversing direction and cancelling out the Earth's magnetic field)
question
Where do most earthquakes and volcanoes occur?
answer
Ring of fire and near the edges of tectonic plates
question
What's the significance of magnetic strips- what do they tell us?
answer
They hold a record of reversals in Earth's magnetic field
question
When did plate tectonics begin?
answer
3.2 billion years ago
question
What is the difference between an ocean and a sea?
answer
Seas are smaller than oceans and are located where land and ocean meet
question
What two instruments are needed to determine your longitude using the sun- why?
answer
sextant (determining latitude) and chronometer
question
What were the main stimuli to European voyages of exploration during the Age of Discovery?
answer
Trade, military one-upmanship
question
Why is the oldest ocean floor so young?
answer
Subduction. Oceanic crust gets colder and denser w/ age. It sinks into the upper mantle and is essentially a continuing cycle.
question
How could you convince a 10 yr old that the Earth is round?
answer
A. You could take them to the ocean and watch how ships don't just appear on the horizon but rise above the curve on the planet B. The fact that shadows change over time would not happen on a flat planet
question
How is plate tectonics related to the rock cycle
answer
Earth materials get melted, buried, lifted, weathers and is pushed by the plate tectonic process. Rocks are this way because of this.
question
What is the curie point and why is it important regarding paleomagnetism?
answer
Temperature when materials lose their magnetic properties, replaced by induced magnetism
question
Why was determining longitude so important? Why is it more difficult than determining latitude? How was the problem solved?
answer
It's the key to oceanic exploration and mapping. Inventing a sturdy clock that ran at a constant rate. A chronometer was the solution.
question
How is oceanography different from most of the other sciences?
answer
It involves many different kinds of sciences and not just one thing specifically. For example, oceanography involves geology.
question
Compare the five main oceans.
answer
Pacific= largest/ deepest Arctic= smallest, shallowest, ice-covered Atlantic= second largest, almost as deep Indian= mainly in southern hemisphere, almost as deep Antarctic Ocean= connects pacific, atlantic, indian oceans and is larger than the atlantic
question
What drives plate tectonics?
answer
Convection in the mantle
question
What did we learn about Mars (past and present)
answer
Today, Mars has no magnetic field but that it's not always been the case. It had 20 to 30x the strength of Earth
question
When did Darwin's voyage on the Beagle take place and what was it's focus?
answer
Focus was to discover many organisms and it took place from 1831-36
question
List four ways that early explorers navigated the ocean
answer
1) following the coast line 2) map of places and general direction 3) using the sun and time of day 4) using the stars
question
Who invented the first navigation compass and why was it such a big deal?
answer
Chinese, it used the magnetic field to determine location and was a reverse tribute
question
What was so special about the Challenger expedition in 1872?
answer
one of the first purely scientific oceanographic expeditions
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Unlock answers
question
What is special about the Sargasso Sea?
answer
It is defined by the surrounding ocean currents
question
List Four Reasons to Care about the Ocean
answer
Lots of life (50% species), produces 70% of O2, 71% of Earth's surface, major source (20% animal protein)
question
Compare Ocean depths to land heights
answer
ocean is 4.5 times greater than average land elevation
question
what percent of Earth is covered with water?
answer
97%
question
What percent of Earth's water is found in the ocean
answer
71%
question
Compare and contrast the following (hypothesis, theory, law, fact)
answer
Hypothesis: Tentative explanations proposed Theory: Patterns emerge. If one or more of the relationships hold the hypothesis becomes a theory Law: Theories that evolve into larger constructs Facts: Law and theory can be statements of fact
question
The ocean compromises what percent of Earth's mass?
answer
0.02%
question
Largest animal to ever inhibit Earth. What does it eat?
answer
Blue Whale. Eats up to 40 million krill a day
question
Why do waves break as they come ashore?
answer
Water is slowed by contact with the sea bed while the top of the wave is still moving fast so it rolls over and breaks
question
Why is there so much life around volcanic islands (seamounts)?
answer
There's lots of nutrients because the deep ocean currents collide with the islands flanks
question
What do tuna eat and what eats them?
answer
Tuna eat plankton feeders and sharks eat tuna
question
Why do hammerhead sharks come to seamounts?
answer
The locals of the seamounts provide a cleaning service
question
what do sardines eat and what four organisms eat them?
answer
Sardines eat plankton and cape gullets, sharks (bronze whaler), dolphins, and whales eat them
question
Where do we find some of the roughest conditions? What does this do to the ocean productivity?
answer
Roughest conditions found near (south Atlantic) poles. it enriches the surface waters (food in abundance)
question
Basis of all life in the ocean?
answer
fighter plankton
question
largest migration of life on the planet. explain.
answer
Disappearance of the sun triggers 1,000 million tons of sea creatures searching for food near the surface (graze on fighter plankton)
question
Why do sea turtles lay their eggs on the same day?
answer
so predators on the beach are overwhelmed so many babies get to the water
question
why do herring go into shallow water?
answer
to breed
question
why do grey whales migrate such great distances?
answer
seeking the krill that came to feed off the herring eggs
question
how do killer whales kill a grey whale calf?
answer
they force themselves between mother and calf then leap onto it and push it under (drown it) and kill it
question
what is special about the North Star (Polaris) and why was it so important in early navigation?
answer
It doesn't move so you can refer to it for navigation
question
Where did the Cook voyages go and what were their contributions?
answer
Went to South Pacific. They found data on ocean depths, wind directions, water temperatures, and surface currents
question
What was the echo sounder and why was this important to oceanography?
answer
It allowed measurements of seafloor bathymetry
question
Satellites are being used more and more to sturdy the oceans- why are they so valuable?
answer
They gather large scale data over short time periods
question
What prompted colonization of Polynesia and Viking exploration
answer
economic reasons
question
why did the Chinese set out in the 1400's to launch "the greatest fleet the world had ever known"?
answer
To explore the other side of the world and convince nations China was the only civilized state
question
Why is meant by "reverse tribute"?
answer
Giving things to people to show their wealth
question
Who discovered North America?
answer
Vikings
question
What research question was the focus of the Glomar Challenge?
answer
To test a controversial hypothesis about the history of the ocean floor
question
When did oceanographic institutions get established and why?
answer
they evolved to ensure continuity of effort when demands became greater than any single voyages capability
question
Describe the initial surface of the Earth
answer
Sandy with lots of craters from collision
question
How and when did the moon form?
answer
3.9 billion years ago. Molten debris coalesced together after collision with something the size of Mars
question
"habital" zone
answer
right distance from the sun so the oceans don't boil away/ freeze
question
where did the water come from the eventually filled the oceans?
answer
Commets showered earth with water
question
What is a thermophile?
answer
Organisms that can live in extreme environments
question
Whats the oxygen revolution? what caused it?
answer
Photosynthetic organisms producing enough oxygen to oxidize minerals dissolved in ocean and surface sediments
question
what's the magnetic field do and how has it influenced how Earth developed?
answer
Magnetic field deflects solar wind and preserves our air
question
how do we think the planets formed and why do we have rocky and gases planets?
answer
Planets formed from space debris gravitating and being held together. We have rocky and gaseous planets because of their distance from the sun and solar winds
question
Three sources of hear that caused early earth to be molten?
answer
Frictional heating, impacts, radioactive decay
question
How does the composition of the crust differ from the whole-earth composition?
answer
The crust composition has light elements up and heavy elements down
question
Compare and contrast the lithosphere and asthenosphere
answer
Lithosphere: cool, outer layer, 70-200km, composed of continental/oceanic crusts and uppermost portion of mantle Asthenosphere: hot, partially melted, slowly flowing layer of upper mantle, 350-650km
question
Three types of plate boundaries and what occurs at each
answer
Divergent: spreading centers, new crust Convergent: sudbuction, crust destroyed Fault: sliding, lithosphere breaks
question
How old are the oldest ocean rocks- why so young?
answer
Less than 200 million years old because sediments are conducted at a plates leading edge
question
Greatest objections to Wegner's hypothesis?
answer
That he only selected data supporting his hypothesis, ignoring contrary evidence
question
Why is the Earth's interior still hot?
answer
Radioactive elements within Earth's core and mantle continue to decay and produce heat
question
What is a volcanic island arc? Where do they form?
answer
Curving chains of volcanic islands/ seamounts that occurs parallel to concave edges of trenches
question
Would the most violent earthquakes be associated with spreading centers or subduction zones? why?
answer
Subduction zones because there was no evidence of new crust spreading centers must be balanced by destruction the crust plunges into the mantle(subduction zones are deeper and more violent)
question
What's a hot spot and how can they be used to determine plate motion and rate?
answer
Plumes of magma rising from stationary sources of heat in the mantle
question
Why are tectonic terranes and how do they form?
answer
Isolated part of seafloor, island arc, plateau, continental crust, or sediment brought by seafloor spreading to a position adjacent to a larger continental mass
question
What does magnetic field do for us?
answer
It's a force field that protects us from space weather and radiation
question
how can ancient pottery be used to help us understand the magnetic field?
answer
Pottery records the Earth's magnetic field when it goes into the film. We know the rate of change in the magnetic field has been up and down but the last 300 years there has been a rapid fall
question
What would happen if the liquid core stopped moved?
answer
the dynamo would shut down
question
How fast is Earth's core cooling?
answer
100 degrees per billion years
question
How often have magnetic field reversals take place?
answer
Once every 200,000 years
question
What has happened in the South Atlantic?
answer
Magnetic anomalies have begun under the ocean (reversing direction and cancelling out the Earth's magnetic field)
question
Where do most earthquakes and volcanoes occur?
answer
Ring of fire and near the edges of tectonic plates
question
What's the significance of magnetic strips- what do they tell us?
answer
They hold a record of reversals in Earth's magnetic field
question
When did plate tectonics begin?
answer
3.2 billion years ago
question
What is the difference between an ocean and a sea?
answer
Seas are smaller than oceans and are located where land and ocean meet
question
What two instruments are needed to determine your longitude using the sun- why?
answer
sextant (determining latitude) and chronometer
question
What were the main stimuli to European voyages of exploration during the Age of Discovery?
answer
Trade, military one-upmanship
question
Why is the oldest ocean floor so young?
answer
Subduction. Oceanic crust gets colder and denser w/ age. It sinks into the upper mantle and is essentially a continuing cycle.
question
How could you convince a 10 yr old that the Earth is round?
answer
A. You could take them to the ocean and watch how ships don't just appear on the horizon but rise above the curve on the planet B. The fact that shadows change over time would not happen on a flat planet
question
How is plate tectonics related to the rock cycle
answer
Earth materials get melted, buried, lifted, weathers and is pushed by the plate tectonic process. Rocks are this way because of this.
question
What is the curie point and why is it important regarding paleomagnetism?
answer
Temperature when materials lose their magnetic properties, replaced by induced magnetism
question
Why was determining longitude so important? Why is it more difficult than determining latitude? How was the problem solved?
answer
It's the key to oceanic exploration and mapping. Inventing a sturdy clock that ran at a constant rate. A chronometer was the solution.
question
How is oceanography different from most of the other sciences?
answer
It involves many different kinds of sciences and not just one thing specifically. For example, oceanography involves geology.
question
Compare the five main oceans.
answer
Pacific= largest/ deepest Arctic= smallest, shallowest, ice-covered Atlantic= second largest, almost as deep Indian= mainly in southern hemisphere, almost as deep Antarctic Ocean= connects pacific, atlantic, indian oceans and is larger than the atlantic
question
What drives plate tectonics?
answer
Convection in the mantle
question
What did we learn about Mars (past and present)
answer
Today, Mars has no magnetic field but that it's not always been the case. It had 20 to 30x the strength of Earth
question
When did Darwin's voyage on the Beagle take place and what was it's focus?
answer
Focus was to discover many organisms and it took place from 1831-36
question
List four ways that early explorers navigated the ocean
answer
1) following the coast line 2) map of places and general direction 3) using the sun and time of day 4) using the stars
question
Who invented the first navigation compass and why was it such a big deal?
answer
Chinese, it used the magnetic field to determine location and was a reverse tribute
question
What was so special about the Challenger expedition in 1872?
answer
one of the first purely scientific oceanographic expeditions