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GIS

renske koets English 115 cards

GIS

Cards in this deck (115)

  1. 1—
  2. 2Lithospherecool and rigid
    does not deform
  3. 3Asthenospherehot and viscous
    deform freely
  4. 4oceanic crust6 km
    BASALT volcanic rocks
    Silicate and magnesium
    > dense than continental crust
  5. 5continental crust35 km
    GRANITES hard rocks
    Silicate and aluminum
    < dense than oceanic crust
  6. 6Seafloor spreadingDivergence of adjacent plates at ocean ridges
  7. 7accreting plate boundaryOcean ridges
    1. plate divergence
    2. hot mantle rock ascends to fill gap
    3. cools down and becomes rigid
  8. 8Divergent Margin<- ->
    Spreading
    creation of oceanic lithosphere
    Ridge / Rift
    Volcanic activity
    Extension
  9. 9relationship between mean oceanic depth (d) and lithosphere age (t)d = 2500 + 350 sqrt [t]
    t is Ma
    d is in meters
  10. 10Convergent-><-
    Subduction
    oceanic lithosphere destroyed
    Trench
    Volcanic activity
    Compression
  11. 11Tranform->
    <-
    Earthquakes within crust
    Strike-slip
  12. 12plate boundaries 1. divergent 2. convergent 3. transformplate boundaries 1. divergent 2. convergent 3. transform
  13. 13Trench pullplate tectonic force that pushes the slab near trench downward
  14. 14Plate boundaries classified on increasing energy required to sustain tectonic system 1. 2. 3.Plate boundaries classified on increasing energy required to sustain tectonic system
    1. Diverent (extension)
    2. Transform (strike slip)
    3. Convergent (compression)
  15. 15Continental driftrelative motion of continents draged by the movement of the lithosphere.
  16. 16isostatic rebound post-glacial rebound1. Ice sheets melted
    2. weight of lithosphere became less
    3. lithosphere began to rise up
    4. back to isostatic equilibrium
    all possible due to liquid asthenosphere
  17. 17Active margin (subduction zone)- convergent
    - narrow continental margin
    - withour or not much sediment
    - tectonically active
  18. 18Andean type subduction zonesubduction of oceanic lithosphere under continental lithosphere
    forms trench
  19. 19Oceanic arc type of subduction zonesubduction of oceanic lithosphere under oceanic lithosphere
    forms trench
  20. 20Passive margin- wide continental margin
    - thick sediment accumulation
    - no plate boundary
    -little tectonic activity
  21. 21IsostasyThe earth's outer layer thends towards gravitational equilibrium by height adjustments between areas of different relative bouyancy.
    oceanic crust is below sealevel, whereas continental crust is higher.
  22. 22submarine canyoncut in continental slope
    channel to transport sediment into deep ocean
  23. 23turbidity currenterosive action of sediment and water mixture that are denser than seawater
    flow and scour out canyons.
  24. 24marginal basin back-arc basinsmall ocean basin opens up on the far side of island arc from trench.marginal basin back-arc basin
  25. 25—
  26. 263 sources of Earth's internal heat:;1. heat remaining from initial accretion
    2. gravitational energy released from the formation of the core
    3. radiogenic heating within the mantle and crust
  27. 27Major heat component: radiogenic heat get to surface by?conduction
    convection
    advection
  28. 28heat flow equationq = k delta (T) / d
    where k is thermal conductivity
  29. 29What does the heat flow in Earth's surface reveal?information abuot the nature of the rocks and processes that affect the lithosphere
  30. 30As newly formed lithosphere moves away from an oceanic ridge, heat flow ( decreases / increases ) ?Heat flow decreases
  31. 31Thermal evolution: Plate modellithosphere is produced at a mid-ocean ridge with constant thickness
    T at the base of the plate corresponds to its temperature of formation
  32. 32Thermal evolution: Boundary-layer modellithosphere does not have a constant thickness
    thickens and subsides as it cools and moves away from ridge
  33. 33Why does the plate model fits better for older lithosphere?after cooling the thickness remains more or less constant from a certain thickness until the plate is subducted.
  34. 34thermal evolution models predict variation between?ocean depth and age^(1/2)
  35. 35Main flaw of theoretical model for the thermal evolution of the oceanic lithosphere?The thermal models are based on the assumption that heat is lost by conduction only, whereas other mechanisms; such as convenction and advection operate aswell.
  36. 36The isotherm at the base of the lithosphere is at how much degrees?at 1300 degrees from 100 km
  37. 37plates move around a pole of rotation. The further from the pole of rotation, the ( faster / slower ? ) the spreading velocity?the further from the pole of rotation, the *faster* the spreading velocity
  38. 38fast spreading ridge topgraphyfast spreading ridge topgraphy
  39. 39slow spreading ridge topographyslow spreading ridge topography
  40. 40Seismic velocity P & S wave graphSeismic velocity P &amp; S wave graph
  41. 41—
  42. 42pillow lavaPillow lavas, produced
    when lava erupts on the
    ocean floor.    pillow lava
  43. 43sheeted dikespathway for molten magma that rose from mantle to the seafloor. The magam that did not reach the surface solidified as dikes.
  44. 44GabbroCoarse grained intrusive igneous rock formed from the slow cooling of magma deep beneath the Earth's surface.
  45. 45Mantle exisits of:PERIODITE:
    olivine
    pyroxene
    serpentinite = Olivine + Pyroxene
  46. 46How do the different layers look like?How do the different layers look like?
  47. 47MohoThe crust mantle boundaryMoho
  48. 48Explain the abrupt change in the seismic velocity gradient from layer 2 to layer 3?Seismic velocities increase more in layer 2 than 3 because basalts and lavas have more cracks and fissures (more sensitive
    to pressure changes) than the gabbros.
    extrusive -> intrusive transition!    Explain the abrupt change in the seismic velocity gradient from layer 2 to layer 3?
  49. 49ophiolitesoceanic crust (altered) which is now emplaces on land.
  50. 50extrusive / igneous rockfine grained structure.
    less time to cool down.
    Crystalized from magma at the Earth surface.    extrusive / igneous rock
  51. 51Intrusive / plutonic rocksCoarse grained structure.
    More time to cool down.
    Crystalized from magma beneath Earth surface (big crystals!)    Intrusive / plutonic rocks
  52. 52P waveearthquake wave travels to core while being refracted
  53. 53s waveshear wave moving particles perpendicular to their direction of propagation.
    earthquake wave is stoped by liquid core of the earth and does no travel further.
  54. 54emergent normal fault blind normal faultemergent normal fault blind normal fault
  55. 55—
  56. 56thrustthrust
  57. 57overthrustingdisplacement and tectonic emplacement of hanging-wall rocks
  58. 58thrust-sheets (nappes)hanging-wall rocks formed by overthrusting
  59. 59allochtonousrocks within thrusts sheets have been translated a long distance away form their original site
  60. 60autochtonousstay at the original possition
  61. 61wrench zonetwo adjecent blocks move along the wrench zone in strike slip system
  62. 62sinistral faultobserver on one block other block moves to the left
  63. 63dextral faultobserver on one block other block moves to the right
  64. 64earthquakemass movement in earth resulting from slip along a fault zone releasing strain accumulated by tectonic processes
  65. 65Body waves: P & SBody waves: P &amp; S
  66. 66Surface waves Love & RayleighSurface waves Love &amp; Rayleigh
  67. 67seismogramgraph representing earthquake in 3 directions
  68. 68Location of earthquake can be determined from?the time difference between S and P waves at from at least 3 stations
  69. 69Birch lawincreasing linear relationship between seismic velocity and rock density
  70. 70Why can't S-waves travel through liquids?liquids lack shear strength holding the molecules together. S-waves need a medium that is rigid enough to propagate.
  71. 71... = P velecotiy ... = S velocityalpha (r) = P velocity ~ 5 km/s
    beta (r) = S velocity ~ 2-3 km/s
  72. 723 types of earthquake behaviour3 types of earthquake behaviour
  73. 73aseismic tectonic plate movementwithout earthquakes: smooth gliding between 2 plates
  74. 74stick-and-slip tectonic plate movementplates remain coupled for a long time, until stress builds up to critical level, and plates slip during the earthquake
    STRENGHT MATERIAL = STRESS
  75. 75Magnitude earthquake is given by1. local (Richter magnitude)
    2. surface-wave
    3. body-wave
    4. moment
    5. Energy
  76. 76seismic momentmagnitude of earthquake based on the area, the average amount of slip and the force required to overcome the friction
  77. 77Gutenberg-Richter lawlog10 (N seismic events) = magnitude
  78. 78Bath's lawaverage difference in magnitude between a mainshock and its largest aftershock 1.2
  79. 79Omori lawaftershock decay rate (frequency)
    number of aftershocks drop over time
  80. 80focal mechanism of earthquake is based on which angles?1. strike angle (phi) = azimuthal
    2. dip angle (small delta) = how steep
    3. slip angle (labda) = relative motion described by 1 & 2
  81. 81Focal beach balls 1. strike slip 2. normal faults / extension 3. reverse / thrust faults / compressionFocal beach balls 1. strike slip 2. normal faults / extension 3. reverse / thrust faults / compression
  82. 82Seismic reflection methodairgun sources are towed behind a ship and fire when the ship is moving to record data based on change in reflectivity
  83. 83seismic impedance= rock density * seismic wave velocity
  84. 84Stacking methodto improve signal to noise ratio, reflections have small amplitude.Stacking method
  85. 85TOTAL group Pangea IIInumber 1 most powerful supercomputer
  86. 86structural interpretationfaults & folds
    sinking & uplift of land
    structural trends
    structural features
  87. 87stratigraphic interpretationunconformities: surface separating two rock masses of different ages (sediment deposition was not continuous)
    stratal packages (rock layers)
    facies / lithologies: part a layer that differs from the adjacent layers by lithological composition.
    ages
  88. 88TWT in seismic reflection graphtwo way time
    time the seismic wave travels up and down.
  89. 89geological logsvisual inspection of samples brought to the surface
  90. 90geophysical logsphysical measurements made by instruments lowered into the hole
    - sonic
    - resisitivity
    - porosity
    - lithology
  91. 91Sonic (velocity) logLog displays the interval transit time of acoustic energy emitted and detected
  92. 92lithology logGamma ray: measures radiation
    SP: measurement vs depth of potential difference in wellbore and electrode at surface
    deflection to right = Shale
    deflection to left = Sand
  93. 93Resistivity logshigh resistivity = hydrocarbons & low porosity
    low resistivity = Shale & wet sand
    seperation in graph = formation fluid is different from drilling fluid
  94. 94Porosity logsDensity porosity: measure bulk density of formation (rock & fluids)
    Neutron porosity: measure hydrogen content
  95. 95Porosity graphdeflection to left = more porous
    deflection to right = less porous
    neuron < density = shale
    neuron > density = Gas Sand
    neuron = density = Wet Sand V Oil Sand
  96. 96Contourite driftelongated sedimentary accumulation produced by ocean bottom currents
    assymetric moat and mound
  97. 97TurbiditesChannel levee system
    symmetric gull-wing
    (asymmetry controlled by coriolis force)
  98. 98Short-period OBSsrecord high-frequency motions
    small short period eathquakes
  99. 99Long-period OBSsrecord broader range of motion
    mid-sized earthquakes
    seismic activity far from the instrument
  100. 100transmission of acoustic waves is ... for a medium with higher densityfaster
  101. 101gravity methodgravity method
  102. 102mgal10^-5 m/s^2
  103. 103Gravity anomalieslocal variations in gravity that result from topographic and subsurface density variations with A of several mgal
    = measurement of g - theoretical value of g
  104. 104Geoidis the shape that the ocean surface would take under the influence of the gravity of Earth
    = NOT ROUND!
  105. 105Gravimetermeasures gravitational field using a spring
  106. 106Free air correctionA compensation factor used in gravitational surveys that takes into account the decrease in the force of gravity with increasing altitude
  107. 107Bouguer correctioncorrection for the height at which it is measured AND the attraction of terrain
    ROOT > MOUNTAIN = negative bouguer anomaly
  108. 108Thin crust produces .... bouguer anomalyincreased positive
  109. 109Gracesatellites mapping changes in gravity over time to monitor underground water storage, sea level, ocean currents and ice sheets. Has no vertical resolution. Cannot distinguish water as snow, soil moisture, or ground water
  110. 110Ground water storage =TWS - (SW + SM + SP)
    Total water storage (satellite) - reservoir storage (country specific data) - soil moisture (satellite) - snow water equivalent (country specific data)
  111. 111total water storage =Delta TWS = P - (ET + Q)
    precipation (country specific data) - Evapotranspiration (satellite) - River discharge (country Specific data)
  112. 112Atmospheric teleconnectionsclimate anomalies being related to each other at large distancesAtmospheric teleconnections
  113. 113North Atlantic Oscillation (NAO)dipole of pressure field between Iceland and the Azores
  114. 114NAO+ warm wet winters europe dry southNAO+ warm wet winters europe dry south
  115. 115NAO- westerly winds are shifted southwards precipation over south europeNAO- westerly winds are shifted southwards precipation over south europe

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Flashcards on GIS, created by renske koets on 08/12/2022.
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renske koets
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