9/8 Flashcards
What is science?
Science is an evidence based process that we use to understand the natural world
How does the scientific method work?
-We make observations
-come up with a hypothesis to explain observation
-use the hypothesis to make predictions
-test the predictions
-discuss the results
What is a hypothesis?
A testable statement that is supported or not supported
Why must a hypothesis be testable?
If it is not testable, it is just a speculation and not science
Why do changes in a hypothesis represent the success, rather than the failure, of the scientific method?
They represent the progress of science to continually improve and provide more meaningful solutions
What are the differences between scientific hypothesis, theories, and scientific facts?
-A hypothesis is a testable statement
-theories are major ideas that are supported by many years of experiments and observations (strongest scientific idea)
-facts are direct and repeatable evidence
Why is it important to look at the credentials and biases of anyone making a scientific claim?
People can make claims because they are being paid to do so, or are profiting off of the claim, or they may not be qualified to make the claim or speak about the subject
What is the difference between primary literature and secondary literature? Why is it important to check these sources when you are evaluating a scientific claim?
Primary literature includes research and secondary literature Interprets and analyzes the primary sources. When evaluating a scientific claim you want to make sure that you have a primary source
What is the difference between correlation and causation?
Correlation does not always show causation. Just because two things happen at the same time it doesn’t mean that one cause the other to happen we need to find more evidence of causation then just closeness in time
What is pseudoscience?
Pseudoscience is a proposition, a finding or a system of explanation that is presented as science but that lacks the rigor essential to the scientific method. Pseudoscience can also be the result of research that is based on faulty premises, a flawed experimental design or bad data
How are the ways that Geoscientists study the earth different from the ways that a physicist or a chemist might?
Earth scientist combine concepts from other disciplines. Studying the earths system is unique because you study the range of scale, the range of time, and the need to visualize what cannot be seen.
How does qualitative data differ from quantitative data?
Quantitative data are data about numeric variables (e.g. how many; how much; or how often). Qualitative data are measures of ‘types’ and may be represented by a name, symbol, or a number code. Qualitative data are data about categorical variables (e.g. what type).
How are interpretations different from data?
Data collection is the systematic recording of information; data analysis involves working to uncover patterns and trends in datasets; data interpretation involves explaining those patterns and trends.
What is the principle of uniformitarianism?
the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in the past and apply everywhere in the universe.
How does the modern view of uniformitarianism embrace natural phenomena that we can’t directly observe?
If you can understand the geological process that are responsible for things you presently see in nature, you can infer that similar processes are responsible for similar features in ancient rocks and landscapes.
What is the system? What are the components of a system?
Hey system is a group of interrelated parts that function as a complex whole. The components of a system or reservoir of matter or energy, an attribute of a system (such as temperature or pressure), or a sub system that can have its only components
Reservoir, stock, flux
The contents of a Reservoir are called a stock. Movement of matter or energy from one reservoir to another is called a flux. For example a reservoir is a holder, stock is the content that is being held, flux is the contents that are flowing out of the reservoir
Earth subsystems and major spheres
-atmosphere: envelope of gas surrounding earth
-hydrosphere: reservoirs of liquid water
-cryosphere: reservoirs of frozen water (snow and ice)
-biosphere: all living organisms
-geodphere: solid and molten minerals and rocks
The interactions of different components make up the subsystems of the earth system.
-climate system: interactions between the atmosphere, hydrosphere, cryosphere, biosphere, and geosphere. Controls the surface environment and temperature.
-plate tectonic system: interactions between the lithosphere, asthenosphere, and deep mantle. Create mountains and produce volcanos that resupply the atmosphere and oceans with water and gases.
-geodynamo system: interactions between the earths fluid outer core and solid inner core. Generates the magnetic feild
Describe the two heat engines that power the earth system
 Internal heat is powered by heat energy deep within the interior of the planet. The system drives movement in the mantle and core, supplying the energy that melts rocks, moves continents, and lifts up mountains. The internal heat engine powers the plate tectonics system and the climate system.
Earths external heat engine is powered by the sun. It energizes the atmosphere and oceans and is responsible for earths climate and weather
Describe balancing feedback versus reinforcing feedback and be able to recognize which is which
Reinforcing feedback (positive) diminishes the stability of a system. They force accelerated change in the system. They promote a cascade of events that propels the system towards accelerating change.
Bouncing feedbacks enhance the stability of a system. They counteract the fact of the initial event and help to regulate the system
Reinforcing feedbacks amplify change and balancing feedbacks resist change
What is the electric blanket system
When you turn up the controller, the temperature of the blanket increases, which causes your body temperature to increase. This is a positive coupling because when the blank a temperature increases your body temperature also increases. If your body temperature increases above its comfort level, you decrease the heat coming from the blanket by turning down the controller. This is a negative coupling because when your body temperature increases, the blanket temperature decreases.
What is the definition of a rock
Rocks are naturally occurring solids composed of one or more minerals. Rocks Our a record of the environment in which it is formed
How do igneous rocks form?
Igneous rocks are formed when molten material cools and crystallizes.
What is magma and how is it different from lava?
When molten rock is below earth surface it is called magma. When molten rock is at earths surface it is called lava.
Lava cools quickly at the earth surface and produces small crystals (extrusive). Magma cools slowly And produces large crystals (intrusive).
What is the difference between an intrusive igneous rock in an extrusive igneous rock? How could you recognize each one?
Extrusive igneous rocks extrude onto the surface. Extrusive igneous rocks are dark. Intrusive igneous rocks intrude into previously existing rocks. intrusive igneous rocks are light colored.
How do metamorphic rocks form?
Metamorphic rocks form when previously existing rocks undergo physical and mineralogical changes by intense heating, intense pressure, or exposure to hydrothermal fluids. Think of them as being cooked and or squashed
How could you recognize a Metamorphic rock?
They contain unusual minerals that only form incredible temperatures and pressures like large crystals. They can also have a layer like fabric called foliation which is a sign of intention pressure.
Give an example of each class of sedimentary rock and explain how it forms
-Solid chunks such as gravel, sand, silt, and mud are cemented to form clastic sedimentary rocks.
-Dissolved ions in solution, which can be precipitated out as chemical sedimentary rocks.
-Dissolved ions in solution can also go into living tissues of organisms and make them into hard parts like shells and then deposit when the organism dies to form biochemical sedimentary rocks.
-Organic matter like carbon that is varied can be heated and compressed and transformed into organic sedimentary rock.
Explain the process that transforms a rock into sediment and then into sedimentary rock
Sediments are created by weathering and erosion when rocks are broken down at earths surface and moved away from their source. The sediment is then transported by water, wind, ice etc. and are deposit at depositional environments. The sediment becomes compacted and compaction and cementation cause sediments to lithify into sedimentary rocks (Lithification).
What is the difference between depositional environment and erosional environment?
Depositional environments are places where sediment collects. Erosional environments are sources of sediment, material is being lost from there rather than accumulating there
Why aren’t original environments usually preserved in the rock record?
Because material is being washed from there rather than accumulating there they won’t be preserved. Organisms that live in erosional environments are less likely to be preserved as fossils
What are sedimentary structures and give an example
Sedimentary structures show interactions between sediments in the depositional environment. For example, ripple marks form in currents of water, sand dunes are formed by winds, mud cracks form when wet sediment dries out.
What is a rock formation?
Packages of similar strata (layers) formed over a region are called formations.
What does the transition from one rock formation to another represent?
Transitional lines from one formation to another show that environments have changed dramatically over time
Explain how rocks can move through the rock cycle
Any rock type, under the right circumstances, can be recycled and transformed into any other rock type. The rock cycle is a consequence of plate tectonics. New rocks are produced from magma, old material can be taken back into the mantle at subduction zones
What is paleontology?
The study of fossils
What are fossils?
The physical traces of past life, any remains of an ancient organism or his behavior preserved in rock record
What are trace fossils, what do they record?
The record of an organisms behavior preserved in rock. Includes foot prints, bite marks, feces
What are body fossils? What are macrofossils and microfossils?
The physical remains of an organism preserved in rock. Usually skeleton.
macrofossils- large enough to see with naked eye
Microfossils- can only be seen with a microscope 
What conditions are necessary for an organism to become a fossil?
-hard parts: shell, bones, teeth, woody tissue
-buried rapidly: sediment accumulates fast
-buried in anoxic (oxygen poor) environment
What is taphonomy? What is diagenesis?
Taphonomy: the processes that occur between death and burial
Diagenesis: processes that occur after burial
What eight main processes preserve most fossils?
-freezing or drying: wooly mammoth with soft tissue and hair
-tar or amber: preserves hard parts, soft tissue lost (tar). Preserves hard parts and soft tissue (amber)
-recrystallization: calcite in hard parts reorder themselves and regrow. The mineral biology of the hard parts stays the same. Common with clams and snails
-replacement: hard parts are replaced by other minerals. Mineralogy is different
-carbonization: organic material is distilled under heat and pressure of burial. Carbon film is left behind (how coal is formed)
-molds or casts: molds are impressions of organisms, casts are the 3d filled version of molds
How does per-mineralization preserve a fossil?
Bone and woody plant tissues are porous and after burial those pores fill with groundwater, minerals in the groundwater precipitate and eventually turn the bone or woody tissue into a solid rock.
Why are fossil useful for ecological and environmental studies?
Use them to reconstruct ecosystems and understand climate change over time.
What is the difference between relative and numerical age dating?
Relative age- ordering events without exact time
Numerical age- dates or durations of events
What are strata?
Flat-lying layers
Principles of stratigraphy
-principle of original horizontality: strata are originally deposited in uniform, horizontal sheets
-principle of superposition: in a sequence of strata, each bed is younger than the one below it
-principle of cross-cutting: more recent rocks or structures can cut across older ones
-unconformities: gaps in rocks caused by erosion
Principle of fossil succession
Allows us to determine the relative ages of strata that are far away from eachother. Fossils show a non repeating pattern through time
Why are fossils a good indicator of relative age?
The range (time in which the organism was alive) is useful for relative dating
How do geologists correlate rock outcrops that are far apart?
Strata can be matched together if they contain the same groups of fossils
How did geologists construct the geological time scale
They used fossils to correlate strata all over the world and arrange them in a sequence
How is the geological time scale divided?
Eons, eras, periods, epochs
How were the boundaries for the divisions of the geological timescale chosen?
They mark the times when the fossil record changed dramatically
What is radioactivity? What rules does radioactive decay follow?
-Rate of decay is unique to each radioactive element
-no matter how many there are, half the number of radioactive atoms in a sample will decay
-period of time is called the half life
Parent and daughter atoms
Parent is the more unstable radioactive element that decays into the daughter cell which release energy and particles
Which rock is the best candidate for radiometric dating methods?
Igneous rocks. They form by cooling and locking atoms into place
How to calculate the age of sedimentary rock relative to igneous rocks?
Principles of stratigraphy: sedimentary rock above igneous= younger, intrusion that cuts through both is youngest, the age of sedimentary rock is between the intrusion and igneous ages
How old is the earth?
4.55 billion yo
What are isotopes? How are different isotopes of elements different from each other
Isotopes are different categories of elements. They have different numbers of neutrons
What are the differences between stable isotopes and radioactive isotopes?
Stable means they last forever, radioactive isotopes are unstable and decay over time and change into a different element
What are the two most important stable isotopes used to study earths climate?
Carbon and oxygen
