Exam 1 Flashcards
(129 cards)
1
Q
Sea-Ice Belt
A
Ice surrounding Antarctic
Changes with seasons
Makes Ross Sea waters calm and clear
2
Q
Pack Ice
A
an expanse of large pieces of floating ice driven together into a nearly continuous mass, as occurs in polar seas.
3
Q
Fast Ice
A
ice that extends out from the shore and is attached to it.
4
Q
Keeling Curve
A
The Keeling Curve is a graph which plots the ongoing change in concentration of carbon dioxide in Earth’s atmosphere since 1958. It is based on continuous measurements taken at the Mauna Loa Observatory in Hawaii that began under the supervision of Charles David Keeling.
5
Q
Anthropogenic
A
(chiefly of environmental pollution and pollutants) originating in human activity.
6
Q
Anthropocene
A
relating to or denoting the current geological age, viewed as the period during which human activity has been been the dominant influence on climate and the environment.
7
Q
Laurentide Ice Sheet
A
The Laurentide Ice Sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the northern United States
Maximum extent of glacial ice
8
Q
Last Glacial Maximum
A
The Last Glacial Maximum (LGM) was the last period in the Earth’s climate history during the last glacial period when ice sheets were at their greatest extension. Growth of the ice sheets reached their maximum positions 24,500 BCE. During the LGM, vast ice sheets covered much of North America, northern Europe and Asia. These ice sheets profoundly affected Earth’s climate, causing drought, desertification and a dramatic drop in sea levels
9
Q
Terra Australis Incognita
A
a hypothetical continent first posited in antiquity and which appeared on maps between the 15th and 18th centuries. The existence of Terra Australis was not based on any survey or direct observation, but rather on the idea that continental land in the Northern Hemisphere should be balanced by land in the south
10
Q
Remote Sensing
A
Observing glaciers through satellites?
11
Q
Sea-level equivalent of ice
A
The change in global average sea level that would occur if a given amount of water or ice were added to or removed from the oceans.
12
Q
LC-130 Hercules Aircraft
A
The primary mission of the LC-130 is supporting the scientific community in Antarctica by transporting cargo and personnel from the McMurdo Station to field stations and camps, including the Amundsen–Scott South Pole Station.
The aircraft are equipped with retractable skis that allow the aircraft to land on snow and ice as well as on conventional runways.
13
Q
Vostok ice cores
A
Show changes in CO2 and temperature, correlated together
14
Q
EPICA Ice Cores
A
obtain full documentation of the climatic and atmospheric record archived in Antarctic ice by drilling and analyzing two ice cores and comparing these with their Greenland
15
Q
Greenland Ice core record
A
Ridges represent years
Oxygen/hydrogen isotopes
Methane
Carbon Dioxide
16
Q
Nunatak
A
an isolated peak of rock projecting above a surface of inland ice or snow.
Often landmarks in regions with ice sheets
17
Q
IPCC
A
Intergovernmental Panel on Climate Change
dedicated to the task of providing the world with an objective, scientific view of climate change and its political and economic impacts
18
Q
Gaia Hypothesis
A
Earth is a superorganism that has the ability to regulate its body chemistry and temperature through natural feedback systems
19
Q
What types of ice melting won’t result in sea level changes?
A
Ice shelves or iceburgs under the water
20
Q
Which ice sheet is larger and thicker in Antarctica?
A
East
21
Q
Northern Hemisphere Deglaciation
A
Ice retreat within the last 20,000 years
22
Q
CO2 levels natural
A
Vary between 180 and 280 ppm in natural glacial and interglacial cycles
23
Q
Recent CO2 Levels
A
Increase by 40% to >400 ppm
24
Q
Insolation
A
solar radiation that reaches the earth’s surface. It is measured by the amount of solar energy received per square centimetre per minute.
25
Larsen B Ice Shelf Collapse
January 2002 partially collapsed (area of Rhode Island) with in 3 weeks
Disintegrate by end of the decade
Hotspot of global warming
Weddell Sea by Peninsula
Connected to inland glaciers - impact sea level
26
Wilkins ice shelf collapse
2008 a large portion disintegrated
Rising temperature and earthquakes played a role
Not connected to inland glaciers - negligible impact on sea levels
Effected by global warming
Antarctic peninsula
27
Infrared radiation
Heat radiation
| 49% of the heating of the Earth
28
Uniformitarianism
the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.
Charles Lyell
29
Biosphere
the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms
30
Cryosphere
The cryosphere is the frozen water part of the Earth system. One part of the cryosphere is ice that is found in water. This includes frozen parts of the ocean, such as waters surrounding Antarctica and the Arctic. There are places on Earth that are so cold that water is frozen solid.
31
Exosphere
In the case of bodies with substantial atmospheres, such as Earth's atmosphere, the exosphere is the uppermost layer, where the atmosphere thins out and merges with interplanetary space.
32
Lithosphere
the rigid outer part of the earth, consisting of the crust and upper mantle.
Divided into tectonic plates
33
Phytoplankton
Play a critical role in Earth's regulation of carbon dioxide levels because they use much of the atmospheric CO2 for photosynthesis. With warming temperatures, the ocean current is unable to circulate and provide these organisms with the nutrients needed to thrive, and therefore begin to die, in turn affecting a very large portion of the biological cycle and the earth's temperature.
34
How fast is Arctic ocean sea cover disappearing?
Faster than model predictions
35
What parallels increasing CO2 levels?
Population, GDP, fossil fuels, land use changes
36
Svante Arrhenius
mid 1890s
examined CO2 possible role in glacial-interglacial cycles but ended up predicting a warmer future for Earth's CO2 values continued to increase
37
How does the biosphere impact CO2 in the global carbon cycle?
On short and long time scales
38
How does the lithosphere impact CO2 in the global carbon cycle?
On long time scales
39
Superposition
states that sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top
40
Milankovitch Cycles
Precession, obliquity and eccentricity of earth provide the timing for climate cycles by influencing the amount of insolation reaching areas of Earth
41
Eccentricity
Orbit shape
of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle
42
Obliquity
Tilt
axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane
Earth is 23°
43
Precession
Wobble
precession refers to any of several gravity-induced, slow and continuous changes in an astronomical body's rotational axis or orbital path. Precession of the equinoxes, perihelion precession, changes in the tilt of Earth's axis to its orbit, and the eccentricity of its orbit over tens of thousands of years are all important parts of the astronomical theory of ice ages.
44
Ice House Earth
the earth as it experiences an ice age. Unlike a greenhouse earth, an icehouse earth has ice sheets present, and these sheets wax and wane throughout times known as glacial periods and interglacial periods. During an icehouse earth, greenhouse gases tend to be less abundant, and temperatures tend to be cooler globally. The Earth is currently in an icehouse stage,[5] as ice sheets are present on both poles and glacial periods have occurred at regular intervals over the past million years.
45
Green House Earth
a period in which there are no continental glaciers whatsoever on the planet, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures (SSTs) range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions
46
Snowball Earth
A "snowball earth" is the complete opposite of greenhouse earth, in which the earth's surface is completely frozen over; however, a snowball earth technically does not have continental ice sheets like during the icehouse state.
47
Estuaries
a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea
48
Proxy data
Nonmeteorological data
Ice cores, lake sediments
temperature, moisture, sea level, and chemical composition of the atmosphere
49
Proxy data
Nonmeteorological data
Ice cores, lake sediments
temperature, moisture, sea level, and chemical composition of the atmosphere
50
Reservoirs of Carbon
Ocean, rock, atmosphere, permafrost and biosphere
| Store and release at different rates
51
Primary moderators of atmospheric and oceanic chemistry
Photosynthetic primary producing microorganisms
| Past several billion years
52
2050 Greenhouse gases
Higher than they have been in the last 10 million years
53
Earth may be headed into...
Warm conditions like
a. Pliocene Climate Optimum
b. Mid-Miocene Climatic Optimum
3. warm Eocene
54
When can major ice sheets develop?
When landmasses are positioned close to the polls
55
How is the addition of GHGs to the atmosphere balanced?
Added by volcanic activity and sea floor spreading
Balanced by erosion of mountains and chemical weathering of eroded sediment particles, through which CO2 is extracted from the atmosphere
56
Relative dating
is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. estimated age)
57
Oxygen isotope curves
A graphical plot of values for the relative proportions of two isotopes of oxygen. Correspond to levels of glaciation
58
Paleocene-Eocene Thermal Maximum
The Paleocene-Eocene Thermal Maximum (PETM), which occurred around 56 million years ago, is the most recent event that we can compare today's warming to. Global temperatures rose at least 5°C (9°F), and the PETM warmth lasted 200,000 years before the Earth system was able to remove the extra CO2 from the atmosphere.
In line with current global warming
59
Mid-Miocene Climate Optimum
(from around 17 to 15 million years ago, also known as the MCO for short) – a period of global warmth (perhaps as much as 4-5 oC warmer than today) punctuating the overall cooling trend that has characterised the last 50 million years. Notably, the MCO is associated with (amongst other things) a smaller than modern Antarctic Ice Sheet. This is therefore a very useful period to study as it may serve as an analogue for our warm future, or at the very least, as a vital guide to how the Earth system functions when it’s warmer than today.
60
Pleistocene Glaciation
a series of glacial events separated by interglacial events during the Quaternary period from 2.58 Ma (million years ago) to present. During this period, ice sheets expanded, notably from out of Antarctica and Greenland, and fluctuating ice sheets occurred elsewhere (for example, the Laurentide ice sheet).
61
The Younger Dryas
12,900-11,700 years ago
It was the most recent and longest of several interruptions to the gradual warming of the Earth's climate since the severe Last Glacial Maximum
Caused by ocean currents
62
Medieval Warm Period
also called medieval warm epoch or little climatic optimum, brief climatic interval that is hypothesized to have occurred from approximately 900 ce to 1300 (roughly coinciding with the Middle Ages in Europe), in which relatively warm conditions are said to have prevailed in various parts of the world, though predominantly in the Northern Hemisphere from Greenland eastward through Europe and parts of Asia.
63
Little Ice Age
a period of cooling that occurred after the Medieval Warm Period (Medieval Climate Optimum)
cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, an inherent variability in global climate, or decreases in the human population.
64
Glacial Lake Agassiz
Lake Agassiz was a very large glacial lake located in the middle of the northern part of North America. Fed by glacial meltwater at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined though its mean depth was not as great as that of many major lakes today.
Larger than any lake existing today
65
Global Ocean Conveyor Belt
a constantly moving system of deep-ocean circulation driven by temperature and salinity.
Thermohaline
66
Stratigraphic Principles
1. Law of Superposition
2. Principle of original horizontality
3. Principle of lateral continuity
4. Law of Cross-Cutting Relationships
5. Law of Inclusions
67
Law of Cross-Cutting Relationships
is a principle of geology that states that the geologic feature which cuts another is the younger of the two features.
68
Law of Inclusions
if inclusions (or clasts) are found in a formation, then the inclusions must be older than the formation that contains them.
69
Principle of Lateral Continuity
states that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. As a result, rocks that are otherwise similar, but are now separated by a valley or other erosional feature, can be assumed to be originally continuous
70
Principle of Original Horizontality
states that layers of sediment are originally deposited horizontally under the action of gravity
71
Goldilocks Effect
the Goldilocks zone refers to the habitable zone around a star. The Rare Earth Hypothesis uses the Goldilocks principle in the argument that a planet must neither be too far away from, nor too close to a star and galactic center to support life, while either extreme would result in a planet incapable of supporting life
72
Subduction
the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
73
Transform Fault
a strike-slip fault that offsets a mid-ocean ridge in opposing directions on either side of an axis of seafloor spreading
74
Supercontinent Cycles
the quasi-periodic aggregation and dispersal of Earth's continental crust.
75
Rodinia
The first supercontinent
| assembled 1.3–0.9 billion years ago and broke up 750–600 million years ago
76
Continental Accretion
Oceanic-continental convergence: The required conditions for plate accretion. Accretion is a process by which material is added to a tectonic plate or a landmass. This material may be sediment, volcanic arcs, seamounts or other igneous features.
77
Craton
is an old and stable part of the continental lithosphere, where the lithosphere consist of the earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates.
78
Shield
Craton in which the basement rock crops out at the surface
79
Platform
Craton in which the basement is overlaid by sediments and sedimentary rock
80
Igneous Rocks
Igneous rock is formed through the cooling and solidification of magma or lava.
81
Sedimentary Rock
are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water
82
Metamorphic Rock
is a result of a transformation of a pre-existing rock. The original rock is subjected to very high heat and pressure, which cause obvious physical and/or chemical changes. Examples of these rock types include marble, slate, gneiss, schist
83
Bowen's Reaction Series
Norman L. Bowen who was able to explain why certain types of minerals tend to be found together while others are almost never associated with one another.
one can infer from the minerals present in a rock the relative conditions under which the material had formed
84
Andesite
a dark, fine-grained, brown or grayish volcanic rock that is intermediate in composition between rhyolite and basalt.
85
Basalt
a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow
86
Ring of Fire
a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur. In a 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes)
87
What did early scientists believe about the oceans and continents?
They were permanently fixed and did not move
88
Rivers prior to North American ice sheet
Flowed up to Hudson Bay and into the North Atlantic
89
Rivers after North American ice sheet
Ice melt water flowed to the south, out the Mississippi and Missouri rivers
90
What marks tectonic plates?
Mountain ranges and associated metamorphic and igneous rocks
91
How do continental cratons grow?
Outward by the addition of new material at the edges through continental collision
92
Paleocene-Eocene Thermal Maximum Time
20,000 years to develop
| 250,000 years to recover naturally
93
Upwelling
Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away.
Upwelled water is typically cooler and richer in nutrients
94
Thermohaline Circulation
a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes
95
Downwelling
occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom
96
Ocean gyres
any large system of rotating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis effect
Clockwise in Northern Hemisphere, counter in Southern
97
Surface circulation
Driven by winds
98
Deep-water circulation
Driven by cooling and sinking of water in the polar regions
| Density differences in water masses, controlled by temperature and salinity
99
Hadley cell
Caused by energy gradients between the equator and the poles
Warm air rises at the equator, cools off in the atmosphere and sinks at 30°
Carries heat from equator to poles
100
Pancake Ice
If the ocean is rough, the frazil crystals accumulate into slushy circular disks. A signature feature of pancake ice is raised edges or ridges on the perimeter, caused by the pancakes bumping into each other from the ocean waves.
101
Salt Exclusion
Once it begins to freeze, salt is excluded from the ice crystal in a process known as “brine rejection”, and the surrounding seawater becomes saltier and denser (Ruddimann 2001). The fresh ice floats on the dense water, creating a barrier between the ocean and the atmosphere.
102
Brine Channels
When sea ice forms, freshwater ice is formed first, leaving behind droplets of salty liquid called brine. This brine can get trapped in pockets or channels in the ice. Microscopic organisms in the water get trapped in the brine.
103
Glossopteris
one of the major features of the flora of Gondwana. The distribution of this plant was among the first evidence for continental drift.
104
Lystrosaurus
herbivorous genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica, India, and South Africa.
105
Sea-ice diatoms
Diatoms are likely the most important primary producers within Arctic sea ice. These single celled algae are characterized by their silica frustules and may occur as single cells or in colonies. Diatoms account for about 50 to 75% of all protist species occurring with ice.
106
Frazil ice
soft or amorphous ice formed by the accumulation of ice crystals in water that is too turbulent to freeze solid.
107
Congelation ice
On seawater, congelation ice is ice that forms on the bottom of an established sea ice cover, usually in the form of platelets which coalesce to form solid ice
108
Brine-cicle
forms beneath sea ice when a flow of extremely cold, saline water is introduced to an area of ocean water, being the undersea equivalent of a hollow stalactite or icicle
109
Radiolarians
Biostratigraphic tools
Calibration to published time scales
Hard shells of calcite or aragonite
110
Foraminifera
Biostratigraphy
Give age to surrounding rocks
Affected by changing climate and ocean acidification
111
Mesosaurus
Provided evidence for continental drift
| Land animal - couldn't have crossed Atlantic ocean between Africa and South America
112
Is continental or oceanic crust higher?
Continental because it is thicker and less dense
113
What is the distribution of pelagic life limited by?
Temperature, water-mass locations and boundaries
114
Antarctic Convergence and Polar Frontal Zone Boundary
Separates warm water (calcareous) microorganisms and cold water (siliceous) microorganisms
115
Surface ocean circulation is driven by
Wind stress, Earth's rotation and the Coriolis Effect
116
Circum-Antarctic Current
Continent motions away from Antarctica caused
| Mix the Indian, Atlantic and Pacific oceans
117
Wegener
Proposed changes in plate position, but not the mechanism
Mechanism: C-floor spreading and subduction
Antarctic rocks and fossils were key to confirming Wegener's theory
118
Past levels of CO2
Cenozoic: Glaciation, low levels of CO2
Mesozoic: No glaciation, high levels of CO2
Paleozoic: Glaciation, low levels of CO2
119
Greenhouse Gases
H2O, CH4, CO2
120
How is carbon stored?
Limestone
Fossil Fuels (coal and oil)
Organic shale
Methane hydrate
121
Lake Agassiz
Melt water flowed into Atlantic and stopped heat exchange
Kept heat in the oceans
Gulf stream couldn't reach Europe
Cooled to glacial conditions (YOUNGER DRYAS)
122
Young Dryas was a ____ event
Northern Hemisphere
| NOT Antarctica
123
Venus Goldilocks
No liquid water, no way to remove atmospheric CO2
| Too hot for life
124
Mars Goldilocks
All water is frozen
| No atmospheric CO2 to trap heat
125
Flowing volcanoes
Less silica, magma flowing up from mantle
| Felsic
126
Exploding volcanoes
Subduction zones
More silica and gases
Erupt
Mafic
127
What moves tectonic plates?
1. Gravity
2. Convection currents
3. Rising magma
128
Intrusive Rock
Cool slowly under ground
Form large crystals
Coarse texture
129
Extrusive Rock
Cool quickly at surface
Fine texture
Volcanic
