Term
| D27: If the Sun’s insolation changed enough to increase Earth’s equilibrium temperature by 1 degrees C, how much would Earth’s actual temperature change (assume Earth’s Greenhouse thermostat operates). |
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Definition
| increase way less than 1 degrees |
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Term
| D27: If the Sun’s insolation changed enough to increase Earth’s equilibrium temperature by 1 degrees C in a very short time period (let’s say 10 years), how would Earth’s actual temperature respond? |
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Definition
| The temperature would increase by 1 degrees, then taper downward over 100,000 years |
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Term
| D27: How does the Earth’s surface, on an average, compare to its equilibrium temperature? |
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Definition
| Earth’s surface is 33 degrees Celsius (59 degrees F) warmer than its equilibrium temperature |
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Term
| D27: What is the approximate time scale over which the Earth’s Greenhouse thermostat operates (that is, what is its response time)? |
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Definition
|
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Term
| D27: If the Sun’s insolation changed enough to increase Earth’s equilibrium temperature by 1 degrees C, how much would Earth’s actual temperature change (assume Earth has no Greenhouse gases in its atmosphere). |
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Definition
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Term
| D27: Which process listed below could change the Sun’s insolation? |
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Definition
| A change in the Earth’s distance from the Sun |
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Term
| D28: Which of the following is evidence for glaciation events in the geological record? |
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Definition
| Rocks made up of unsorted, broken up fragment and rocks with scratches etched into them |
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Term
| D28: Why did Hazen entitle his discussion of the Great Oxygenation Event “Red Earth”? |
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Definition
| Oxygen release “rusted” iron in the rocks and ocean |
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Term
| D28: Approximately when did the Great Oxygenation Event begin? |
|
Definition
| End of the Archean/Beginning of the Proterozoic 2.5 BY ago |
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Term
| D28: When, approximately, do we find the first evidence of extensive glaciation on the Earth (transition from a hothouse to an icehouse state)? |
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Definition
| The Late Archean/Beginning of the Proterozoic 2.7-2.4 BY ago |
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Term
| D28: What cycle began during the “Boring Billion”? |
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Definition
|
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Term
| D28: Which statement best describes the “Great Oxygenation Event”? |
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Definition
| A geologically slow event (hundreds of millions of years) where atmospheric oxygen built from nearly 0 to about 1% of its current value |
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Term
| D29: Which of the following observations have field geologists discovered in rocks around the world with ages between 740 and 580 BY ago? |
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Definition
| Bedrock that are scratched and polished, erratic boulders, and moundlike moraines |
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Term
| D29: How do scientists interpret the carbon isotope signature in limestones deposited along the shores of Rodinia during its breakup period (790-740 MY ago)? |
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Definition
| It results from a lot of organic carbon burial |
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Term
| D29: What process/event do most scientists think primarily led to the Snowball Earth events? |
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Definition
| The breakup of Rodinia—proliferation of photosynthetic algae followed by organic carbon burial |
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Term
| D29: What evidence did Hoffman and his Harvard colleagues present that implied the presence of ice all the way down to the equator? |
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Definition
| Thick glacial tillite formations (of the correct age) coupled with magnetic data implying the rocks were close to the equator at the time of their deposition—and were deposited in coastal waters |
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Term
| D29: What do we observe about the carbon isotope signature in limestones deposited along the shores of Rodinia during its breakup period (790-740 MY ago)? |
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Definition
| These limestones are depleted in C-12 (enriched in C-13) compared to today |
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Term
| D29: . What did Hoffman and his Harvard colleagues discover about the carbon isotope signature in limestones that many considered the “smoking gun” for an extensive glaciation event at about 700 MY ago |
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Definition
| Carbonates deposited between 790 and 740 MY ago show enrichment in C-13; Carbonates deposited from 740 to about 680 MY show a depletion of C-13 |
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Term
| D30: Which statement best describes the “Cambrian Explosion”? |
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Definition
| It was the time when many new animal body plans rapidly developed |
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Term
| D30: Which statement below best represents the difference between prokaryotic and eukaryotic cells? |
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Definition
| Prokaryotes: smaller, few organelles, DNA spread throughout cell; Eukaryotes: larger, organelles, DNA confined (mostly) within a nucleus |
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Term
| D30: Approximately when did multicellular life develop? |
|
Definition
| During the Snowball Earth episodes (between 850 and 580 MY ago) |
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Term
| D30: Approximately when did eukaryotic cells develop? |
|
Definition
| Near the Archean/Proterozoic boundary (about 2.1-2.6 BY ago) |
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Term
| D30: What permanent change did the Snowball Earth episodes make in Earth’s systems that allowed the development of multicellular life? |
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Definition
| It led to the permanent buildup of oxygen in Earth’s atmosphere |
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Term
| D30: Describe the current theory about how eukaryotes developed. |
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Definition
| One bacterium engulfed another without digesting it. The resulting cell found it advantageous to be together |
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Term
| D31: How did land plants overcome the challenge of drying out (dessication)? |
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Definition
| Waxy outer coating (cuticule) |
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Term
| D31: Why did the development of trees potentially have climate-changing potential? |
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Definition
| Trees are huge, sequestering a lot of carbon from the atmosphere that could be potentially buried |
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Term
| D31: How did plants overcome the challenge of reproducing on the land? |
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Definition
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Term
| D31: Why is structural support a challenge that plants and animals had to overcome to live on the land? |
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Definition
| Organisms living in the water experience buoyancy that helps support their weight |
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Term
| D31: What potential effect did the creations of the Ouachitas, Northern Appalachians, and the Hercynian Mountains, formed by continental collisions during the late Devonian and Carboniferous, have Earth’s climate? |
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Definition
| Weathering of mountains release calcium ions that marine organisms can use to form calcium carbonate shells, which form into carbonate rocks when the organisms die |
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Term
| D31: How did animals overcome the challenge of locomotion? |
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Definition
| Development of limbs and appendages |
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Term
| D32: What do scientists mean by the term “extinction” as applied to life? |
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Definition
| The death of all members of a single species |
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Term
| D32: Approximately how many families and species went extinct at the end-Permian mass extinction? |
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Definition
| Families: 50%; Species: 90% |
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Term
| D32: How did the end-Permian mass extinction affect mammal-like reptiles? |
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Definition
| It had a severe effect. Only a few species survived. Mammals evolved from them later on. |
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Term
| D32: What were the climatic consequences of the events that caused the end-Permian mass extinction? |
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Definition
| They changed the climate from an icehouse during the Permian to a hothouse throughout the entire Mesozoic Era |
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Term
| D32: Which statement below best describes the difference between background extinctions and mass extinctions? |
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Definition
| Background: Low level, happens slowly all the time due to climate change, tectonic activity, etc; Mass: high level, occurs rapidly over “short” geological time periods of high environmental stress |
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Term
| D32: What caused the end-Permian mass extinction? |
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Definition
| We don’t know for sure, but it probably required multiple causes |
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Term
| D33: What are foraminifera? |
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Definition
| They are large, single-celled plankton organisms that create shells |
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Term
| D33: How do ocean sediment samples show when ice forms (or melts) on the Earth? |
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Definition
| Evaporation favors O-16 (preferentially leaving behind O-17 and O-18). When ice forms, the oceans are left with more O-17 and O-18. Foraminifera use this heavier O to make their skeletons |
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Term
| D33: What do scientists think the most likely caused the changes in Earth’s climate at the Eocene-Oligocene boundary, 33.6 MY ago? |
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Definition
| Uplift of the Himalaya Mountains by releasing more calcium and altering air currents |
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Term
| D33: Which statement below best describes the evidence showing that the far north was ice-free during the Eocene (50 MY ago)? |
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Definition
| Fossils of temperate trees, giant tortoises, early primates, and a hippopotamus-like mammal |
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Term
| D33: How do we know that Antarctica began to become ice covered 33.6 MY ago? |
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Definition
| Oxygen isotopes found in bottom dwelling foraminifera (in ocean sediments) showed an enrichment in O-18 |
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Term
| D33: Why are forams great climate indicators? |
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Definition
| The oxygen isotope composition of their shells reflects the oxygen isotope composition of the water they grow in |
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Term
| D34: Describe Lisiecki and Raymo’s reconstruction of the climate during the last 5 MY. |
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Definition
| It shows a world with variations of climate having a 40,000 year periodicity during the first part of the period and a 100,000 year periodicity during the latter part of the period |
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Term
| D34: What do the sharp up and downs in Lisiecki and Raymo’s recontstruction result from? |
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Definition
| The fluctuation in Earth’s temperatures due to operation of the Milankovitch cycles |
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Term
| D34: Describe the climate during Pleistocene. |
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Definition
| Earth has been in an icehouse state throughout the Pleistocene. During the first part of the period Earth experienced alternating warm and cold periods without the expansion of continental ice sheets; during the later part of the period Earth experienced the expansion and melting of vast continental ice sheets (glacial and interglacial periods) |
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Term
| D34: What are the differences between the “40,000 year world” that occurred during the first part of the Pleistocene and the “100,000 year world” that we’ve been in for the last 1½ million years? |
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Definition
| The overall temperature of the Earth has decreased (it was warmer on average, during the 40,000 year world) and the extremes have become larger |
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Term
| D34: What source do we use to discover information about the last glacial period, beginning 125,000 years ago? |
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Definition
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|
Term
| D34: What have we learned about that period? |
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Definition
| Atmospheric carbon dioxide and temperature have gone up and down nearly in lockstep with each other |
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Term
| D35: Which of the statements is true about how much time glacial and interglacial periods lasted during the Pleistocene? |
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Definition
| Glacials last a lot longer than interglacial periods |
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Term
| D35: Which statement is true about the length the interglacial periods of the Pleistocene? |
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Definition
| There is a lot of variation in the length of interglacial periods; the Holocene has, so far, been longer than most others |
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Term
| D35: Is the Holocene the longest of the interglacials we have record of? |
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Definition
| No, the 4th previous interglacial was longer |
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Term
| D35: Which statement best describes the Holocene? |
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Definition
| It was the latest glacial period in the sequence of the glacial-interglacial periods marking the Quarternary |
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Term
| D35: What characteristic marks the Holocene compared to the interglacial period of the Pleistocene? |
|
Definition
| Stability of temperatures and sea level |
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Term
|
Definition
| how much heat we reflect vs what we absorb - this has to do with positive feedback cycles |
|
|
Term
| What is a negative feedback cycle? |
|
Definition
| low albedo - hot house eventually - this is balanced |
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|
Term
| What is a postive feed back cycle |
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Definition
| high albedo -> snowball earth - this out of balance |
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|
Term
| You must have this to have feedback cycles. |
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Definition
|
|
Term
| What is happening in the carbon cycle when continents break up? |
|
Definition
|
|
Term
| What is happening when mountains are building during carbon cycles? |
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Definition
|
|
Term
| What is primarily responsible for climate change? |
|
Definition
|
|
Term
| Name the three parts of the Milankovitch cycle: |
|
Definition
| procession, obliquity, eccentricity |
|
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Term
|
Definition
| - wobble of tilt - 40,000 years |
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Term
|
Definition
|
|
Term
|
Definition
| ellongated vs circular - 100,000 years |
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|
Term
| What periods do milakovich cycles create? |
|
Definition
|
|
Term
| What happened during the boring billion? |
|
Definition
| This was pre-cambrian - supercontinent cycle - and cratons exsisted |
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|
Term
| What happened during the great oxygenatino event? |
|
Definition
| Oxygen build up in atmosphere - from photosynthetic bacteria in coastline - algae |
|
|
Term
| What do rocks older than 2.5 billion years lack? |
|
Definition
| iron banding from lack of oxygen |
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|
Term
| What do rocks 2.5 billions old or newer have? |
|
Definition
|
|
Term
| When did extensive glaction occur? |
|
Definition
| 6000 million years ago in the Pre-Cambian |
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|
Term
|
Definition
| Granite parts - Continental seeds |
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|
Term
| What do we have to have to form granite? |
|
Definition
|
|
Term
| What does convection cause in the earths crust? |
|
Definition
| Horizontal plate techtonics |
|
|
Term
| What is the Rodinia supercontinent effect? |
|
Definition
|
|
Term
| What is important about the Pangea supercontinent? |
|
Definition
|
|
Term
| Who discovered microbial mats that shows oxygenation? |
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Definition
|
|
Term
| Glaciation occurred during the late proterzoic and we know because? |
|
Definition
| tillites (conglomerate rocks made by glaciers) and magnet baned iron rocks and cap carbonates - high in carbon but inorganic |
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|
Term
| What is the does limestone enriched carbon 13 show? |
|
Definition
| That life that likes carbon 12 is eating it up - shows life exists |
|
|
Term
| What liberates the earth from snowball stage? |
|
Definition
| volcanic outgassing _> CO2 into atmosphere - warming = life |
|
|
Term
| What does the snowball earth do to life? |
|
Definition
|
|
Term
| What is the significance of the Burgess shale? |
|
Definition
| Coredates are found - and all modern phyla (animal body types) present |
|
|
Term
| What are prokaryotic organisms? |
|
Definition
|
|
Term
| What are eukaroytic organisms? |
|
Definition
| Multicellular - combined through phygosytosis |
|
|
Term
| What are problems that life would have to overcome to move to land? |
|
Definition
| gravity _> cells, movement/anchoring, drying out/dessication - (plants wax , animals skin)- transport of nutrients - oxygen - reproduction |
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Term
|
Definition
| coal forests of carboniferous period |
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|
Term
| What was the Devoinian period like? |
|
Definition
| early part was hot house and photosynthetic plants (lycopods) cause the second snowball earth during late in this period. |
|
|
Term
| How was the carboniferous period ended? |
|
Definition
| Mountains formed by Pangea - plants had too much oxygen |
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|
Term
| Describe background extinctions: |
|
Definition
| constant and small - hardly noticed |
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|
Term
| Describe mass extinctions - |
|
Definition
| Sudden major change - Big - rerely ever affect insects - do change course of life on earth - dinosaurs to mammals is example |
|
|
Term
| What does the end Permian Mass extincition involve? |
|
Definition
| Mammals evolved but didn't take over - increasing volcanic activity and syberian traps |
|
|
Term
| What does the Triassic Mass Extiction entail? |
|
Definition
| 76% of marine life died and 20% families - allowed dinasaurs to evolve |
|
|
Term
| What does the KT boundary (End Mesozoic) Mass extinction involve? |
|
Definition
| Killed off dinosaurs - mammals take the earth over! |
|
|
Term
| What happened during the Eocene to the Ogliocene climate transition? |
|
Definition
| Himalayan growth - increase weathering - stop air flow - cold dry climate |
|
|
Term
| What do forminifera mean? |
|
Definition
| increas in O18 (forams) - Antarctic ice increase in O17 |
|
|
Term
| What is the Zachos curve? |
|
Definition
| The huge drop in temperature from curacous to present day (10 % drop over 65 million years) |
|
|
Term
| Why do the Himalayas change weather so much? |
|
Definition
| Drastic change incloud formation and weathering patterns - less carbon in atmosphere more oxygen and more pland death buried = more cooling |
|
|
Term
| What chracterises ther Pleistocene Era? |
|
Definition
| Before holocene - had lots of little ice ages caused by Milankovitch cycles |
|
|
Term
| What are the 3 degrees of cooling periods? |
|
Definition
| Snowball earth(covered) - Icehouse Earth(little less) - Ice ages(less than that) |
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|
Term
| Holocene had what type of climate? |
|
Definition
|
|
Term
| What did Liesiecki and Raymo do? |
|
Definition
| Got ice core and lake bed sediments - climate reconstruction proving Climate forcing during pliestocene with the milankovitch cycles. |
|
|
Term
| Changes in Sea level - Why does it occur? |
|
Definition
| Last glacial period to Holocene - 130 meters lowar - Rising 45 milimeters per year Now rises about 1-2 meters withough changing drastiaclly - 20,2000 years |
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|
Term
|
Definition
|
|
Term
|
Definition
| Cold - high pressure - less winds/dry california / change coral records |
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|
Term
D26 Prep
| |
Approximately when did plate tectonics begin to take over for the older style “vertical” tectonics (massive hot spot volcanism)? |
|
|
Definition
| In the mid Archean (~3 BY ago, ~1.5 BY after Earth’s birth) |
|
|
Term
D26 Prep
Describe the theory of plate tectonics |
|
Definition
| The Earth’s crust and very uppermost mantle is broken up into a series of rigid plates that move horizontally and interact at their boundaries |
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Term
D26 Prep
Why do granitic composition mountain ranges tend to poke up above the ocean floor? |
|
Definition
| Granite is less dense than basalt |
|
|
Term
D26 Prep
Why was the development of the continental crust important in Earth’s history? |
|
Definition
| The granitic crust won’t sink back into the mantle, creating a permanent crust |
|
|
Term
D26 Prep
| |
The mid-ocean ridges represent which type of plate boundary? |
|
|
Definition
|
|
Term
| |
D26 Prep What is granite? |
|
|
Definition
| It is an igneous rock formed by partial melting of basalt (and the melt’s subsequent placement into the upper crust) |
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