Eaos weekly quizes Flashcards
Because the earth is a closed system
The mineral resources on this planet are all we have and - for the foreseeable future - all we will ever have
When vegetation washes off the landscape and settles to the floor of a Fiordland fjord carbon is transferred from the ______ to the _______
Biosphere; Geosphere
When westerly winds blow over the southern ocean, energy is transferred from the ______ to the ______
Atmosphere; hydrosphere
The situation where material has a very long residence time in a reservoir is called
Sequestration
Sedimentary rocks provide clues about
- Geologic activity at the time of deposition
- Past climates
- Surface conditions at the time of deposition
What rock type results from lithification of magma/lava
Igneous rock
What rock type results from heat and pressure
Metamorphic rock
Observations that developed into the principle of uniformitarianism led scientists to conclude that earth must be much ______ than previously thought
Older
What are geological unconformities
- They are contact surfaces between rocks of very different ages
- They represent gaps in the continuity of the geologic record
- They can form through erosion or non-deposition
You will find fossil remains in what type of rock
Sedimentary rock
What is the origin of the element hydrogen in the universe?
The big bang
What is the origin of the element oxygen in the universe?
Nuclear fusion in stars
The color of a star is mainly an indication of its
Temperature
Planets within a stars habitable zone
Receive an amount of solar energy appropriate for liquid water to be present
How did earth get its water
Accretion of meteors
What is the principle evidence for oceans having been present on earths surface throughout most of its history
Marine sedimentary rocks
In addition to earth being within the suns habitable zone, what additional factors have allowed this to be the case
- Earths composition
- Earths magnetic field
- Earths mass
How is Mars currently in ice house climate
- Uv radiation splits atmospheric H2O into H2 and O2 due to weak magnetic field
- Both these can escape easily due to weak gravitational field
- O2 also consumed by oxidization of Iron on surface, hence mars red color
- H2O frozen in the polar ice caps and beneath the surface
What factors have made it difficult for liquid water to be present on the surface of Venus for most of its history
- Venus distance from the sun
- Runaway greenhouse
- Weak magnetic field
Why does the oceanic lithosphere of the pacific plate subduct beneath continental lithosphere of the Australian plate at the Hikurangi convergent plate boundary in the eastern North island of New Zealand
The oceanic lithosphere (pacific plate) is denser than the continental lithosphere (Australian plate) it subducts beneath
What causes mid-ocean ridges to rise high above the surrounding seafloor
Upwelling of hot, buoyant asthenosphere under mid-ocean ridges
Plate motion relative to mid-ocean ridge equation
Kilometres/millions of years = millimetres per year
What kind of plate boundaries occur at mid-ocean ridges
Divergent and Transform plate boundaries
How does paleomagnetism support the theory of plate tectonics
It reveals marine magnetic anomalies which result from seafloor spreading
Evidence used in Alfred Wegener’s continental drift hypothesis
- Fit of the continents
- Locations of past glaciations
- Paleoclimate evidence
- Fossil distribution
- Matching geological units on separate continents
Exposures of Haast schist often show planar cracks that form when overlying rock is removed by erosion. The removal of overburden reduces the pressure acting on the rock, allowing it to expand and crack. What type of weathering mechanism does this process describe
Jointing
When limestone undergoes chemical weathering to produce Ca2+ and 2HCO3-, what type of reaction is occuring
Dissolution
When igneous rocks undergo chemical weathering to produce Kaolinite clay, what type of reaction is occuring
Hydrolysis
Which mineral is most stable at earths surface and weathers slowest
Quartz
True or false: soil forms when rates of erosion are greater than rates of weathering
False
True or False: In biogeochemical cycling, generally the larger the reservoir size (i.e concentration of the element in the reservoir), the slower the flux of the element in/out of the reservoir
True
What sort of timescales do carbon reservoirs in the deep ocean operate on
100 to 1000 years
What are the three main processes that control the removal of CO2 from the atmosphere into long-term sinks
- Chemical weathering of silicate rocks
- Burial of organic matter
- Burial of calcareous rocks
What does the term “stream discharge” refer to
The volume of water flowing past a certain point in the stream per unit of time, typically measured in cubic meters per second (m3/s)
Lateral accretion surfaces in meandering rivers are formed by:
The deposition of sediments on the inner bends of meanders, contributing to point bar growth
What best describes a braided river channel
Multiple channels that intertwine, seperated by temporary sediment deposits known as bars
Helicoidal flow in a meandering river refers to
A corkscrew-like, spiral movement of water from the river bottom to the surface and along the meander bend
If the cross-sectional area of a stream channel is 10 square meters (m2) and the average velocity of water flow is 2 meters per second (m/s), what is the streams discharge
20 m3/s
A hydrograph of a small, urban catchment area shows a rapid rise to peak discharge following a rainfall event, compared to a hydrograph from a large, forested catchment. What is the most likely explanation for this difference
The impermeable surfaces in urban areas increase surface runoff, leading to faster peak discharge
What is stream capture
The process by which one stream erodes the land separating it from another stream, eventually diverting the flow of the captured stream
What characterises an antecedent stream
A stream that has maintained its original course and valley while the surrounding landscape has been uplifted
Which sedimentary particles are most easily transported by water
Clay
Which sedimentary particles are most easily eroded by water
Sand
Marine sediments are generally thickest on the
Continental slope
Marine sediments are generally thinnest on the
mid-ocean ridges
Using understanding of longshore drift, predict the general direction of sediment migration along the Otago coastline
From southwest to northeast
Pelagic sediments are dominated by
Clay particles and the microscopic remains of phytoplankton and zooplankton
Which acoustic tool would you use if you wanted to seismically image up to 200 meters below seafloor
Boomer