Frames of Reference

March 28, 2007

Previously:  v=v’+V, r=r’+R, etc

Medium for light waves? “eather”

Interferometer: E1+E2=Etot, Intensity = |Etot|^2

Vearth=30km/s

c=3×10^8m/s

B=V/C = 10^-4

t1=2(l1/c)*(1/(1-B^2))

t2=2(l2/c)*(1/root(1-B^2))

Assuming ether at rest

(t1-t2)@theta=0 – (t1-t2)@theta=90  = B^2*(l1+l2)/c

Michaelson kept getting B=0

Fitzgerald-Lorentz contraction: dx = dx/gama

gama=1/root(1-B^2)

Einstein-> 1. No such thing as absolute motion, no preferred coordinate system… its all relative

if the ether is at rest there is a preferred system.

2. All inertial observers see the same value for ‘c’

light plays by its own rules: not v=v’+V

Lorentz-Xform

r=ct and r’=ct’ then r!=r’+R

[x';y';z';ct']=L*[x;y;z;ct] where (r^2-c^2*t^2)=(r’^2-c^2*t’^2)

this is fullfilled by:

x’=gama(x-ct*v/t)

y’=y

z’=z

ct’=gama(ct-xv/c)

transform matrix [gama, 0, 0, -gamaB; 0, 1, 0, 0; 0, 0, 1, 0; -gamaB, 0, 0, gama]

Time dilation

t2-t1= gama ((t2-t1)-(x2-x1)*v/c^2))… taken from ct’=gama(ct-xv/c) -> t’=gama(t-xv/c^2)

if X2=X1

dt’=gamadt  iff |B|<1

dt’ > dt

In the same way you can do Time dilation you can also do length contraction.

Plate techtonics

November 1, 2006

Plate techtonics -> equivelent of Survival of Fittest in Biology

3 major Boundry Types

  1. Ridge
  2. Divergent margin
    1. Formation of new oceanic crust by sea floor spreading
    2. Ocean crust -> denser, more mafic, basalt
    3. Extensional Regime, normal faults, shallow seismicity
    4. High Heat flow, decompression melting
    5. Intrusive igneous -> gabbro and basalt (essp. pillow basalts)
    6. Highly fractured rocks -> alot of water goes through -> causes differences in carbon weathering
    7. Tends to fault in three geometric paterns (third often failing to spread)
    8. Tends to also have reafs at shelf slope break
    9. Starts by bowing up, then breaking, finally filling with lakes then ocean
    10. Oceanic crust is much thinner than continental crust
  3. Convergent Margin
    1. Recycling of old, cool oceanic crust (subduction)
    2. Older = Colder = less boyant
    3. Reverse or thrust faulting
    4. Deep seismicity
    5. Increaed Temp = Partial melting of mafic crust = felsic magma
    6. Compression leads to deformation, metamorphism and mountain building
    7. Water, accumulated in pourse ocean basin
    8. Water brought down into asthenosphere = decreasing melting point = more rising magma = mountain building
    9. Also, happens in Continent Continent collision (India subducting under Eurasia) -> causes deformation = himalias
    10. Also, happens in Ocean Ocean collision -> causes island arc = japan
    11. When passive margin collides, subduction reverses causing forlorn basin (like western interior basin in N. America)
  4. Transform margins
    1. No new crust forms
    2. Shear regime -> strike-slip faults, shallow seimicity
    3. San. Andres
  5. Hot spots are fixed points, thus things like Hawaiian islands, show direction and rate of plate movement
  6. Magnetic liniations -> lavas on land dated, and reversal history -> reversal history matched to magnetic liniations, giving us time frames

Driving Forces

  1. Mantal Convection (differences in heat)
  2. Ridge push or slab pull? -> slab pull is thermal model, push is topographic model
  3. Subducted material goes down to the core mantel boundry
  4. Icehouses and Greenhouses, match up with rates of volcanism
  5. The Wilson Cycle (200my cycle), length of ocean basins determains CO2 levels

Implications

Rivers

October 16, 2006

Hypsometric profile (a significant portion is between 2 and 0 or -4 and -6)

Trenches (found where plate is subducting)

Abyssal planes (Oceanic crust spreading away from trench tword subduction)

Elevation = f(uplift – erosion) or techtonic activity – climate

Both uplift and erosion do about .01 – 10 mm/y

A difference of .5mm/y -> 5 km over 10My

Agents of Sediment removal

  1. Glaciers -> not alot of work
  2. Streams -> doing alot of work

Hydrologic cycle (Evaporation and Precipitation)

  1. Oceans E>P
  2. Land P>E

Streams are small (1 bases point) and short lived (2 weeks), but they do all the work

Underground water -> huge amount, flows tword sea, we don’t know alot about it (could be HUGEly important, but noone knows)

Rivers

  1. Amazon is in rainforest (hot and wet) so its not a surprise it has a high flux to drain ratio (heat and pressure are the controls on chemical weathering
  2. Water Table -> cut off between surface and ground water
  3. Laminar flow vs Turbulent flow (laminar is mellow, turbulent causes erosion)
  4. Sheet flow vs Channel Flow (sheet is water across land which forms into channels)
  5. Controls
    1. Velocity of flow (function of gradiant)
    2. Geometry (depth, shape)
    3. Density and viscosity (almost always water)
    4. Surface roughness (what its moving over)
    5. Infiltration capacity
    6. Pre-existing features (special things)
  6. Friction is a good control of velocity
    1. Streams deposit in point bars (where water is slowest)
    2. Flooding causes fine grain to deposit in plane around the river
  7. Channel types
    1. Broad and shallow (arid environment, fast, desert flash flood)
    2. Deep and narrow (meandering streams, human enviornment, mostly suspended load, more coheasive soil)
  8. Channel Pattern
    1. Proximal, Aird climent, bed load streams
    2. Distal Humid Suspended load
  9. Grain size is a function of flow velocity above mud
  10. Below sand -> clays stick together acting like larger particals
  11. Bedload -> stick to bottom, move through rolling, sliding, saltation
    1. Creates bedform
    2. size of particals = competence, controlled by speed
    3. Number of particals = discharge
    4. grains build up in beforms (like sand dunes)
    5. Ripples are 1-3 cm
    6. >3cm = dunes (some times fractals)
    7. Ripples form at low velocity
    8. Dunes at high
    9. Flow Regine concept
  12. Suspended load -> carried through turbulation
  13. Types of Streams
    1. Aluvial Fans
      1. Poximal
      2. Arid -> High velocity
      3. Intermittant
      4. Immature
      5. Bedload
    2. Braided
      1. Broad Shallow channels (really shallow)->Dominately bedload
      2. Transporting sand
      3. arid to semi-arid->Sparse vegitation
      4. Easily eroded banks
      5. Veriable flow
      6. Course to Medium Grained
      7. Poor to Moderate Sorting
    3. Meandering Stream
      1. Has the cutbank and point bar (one is on the other side of the other)
      2. Fining upword sequance
      3. Oxbow lakes (abandoned loops due to flooding eroading a new path)
      4. Distal, humid,veg, lowlands (veg soils are more cohesive making them harder to erode)
      5. Single deep channel
      6. Constant flow and high velocity
      7. Suspended load
      8. Finer Grained, moderate to well sorted (due to loss of grains because these are distal, sorting is proximal vs distal)
      9. Lateral Acreation surfaces (where you can see the fining process)
      10. Higher sand to mud ratio
    4. Deltas
      1. Stream velocity drops -> as does sediment (both bed and suspended)
      2. Progradation
      3. Characterized by modifier
        1. Delta Dominated by River (Mississippi, litterally pushed out into ocean)
        2. High wave action (barrier islands)
        3. High tidal ranges (pushed back in leaving elongated bars)

Drainage Networks

  1. Basins vs Devides
  2. Drainage Patterns
  3. Landforms -> stream Terraces, incised meanders, etc.
  4. Base Level Concept (surface to which erosion is working), below accululation, above erosion

Geologic Time

October 11, 2006

Hutton -> Lyell + Steno

Uniformitarianism

Laws -> methodological
Process  -> methological

Rate -> substantive

State -> Substantive

Methodological is right, substantive is wrong

Geopetals -> fossils, riple marks, etc

Original Continuity -> strata which are now seperate were originally together

Fossile content allows us todo corrilation

If things crosscut, then they are younger than what they crosscut (duh)

Flow has a vasicular texture on top

a sill has a bake zone on both top and bottom

Index Fossils -> good skelletons

Disconformity -> both erotion and sedement can produce one

Sequance statigraphy (how to subdevide rock record)

Diachroneity ->  same thing two different times
When a basen subsides it sinks

Lithostratigraphy (formal naming of rocks based on their lithological units)

Uranium -> Lead dating

Argon -> Argon dating

Argon doesn’t agree with Uranium

Some fossils are Diachronous

Chemostratigraphy -> use of chemical marker for dating

Planets

October 6, 2006

  1. Move with respect to background -> Word planet comes from greek for “wanderer”
  2. planets don’t twinkle

Aristotle (circa 350 BC) -> geocentric model of universe

The Moon

October 4, 2006

Visible phase determained by:

  1. Current phase

  2. Position of the sun in the sky (time)
  3. Position of the moon in the sky

At sunset: full is rising, first quarter is high in the sky, new is setting (third quarter sets at noon)

Moon is offset from Earth Sun by .5*

Orbital plane of moon around earth is different than that of the earth around the sun

Only solar eclipse when phase is new

penumbra = outershadow of moon (only part of the solar eclipse)

umbral shadow = inner shadow of moon (full eclipse) about 300km on earth at a time and never longer than 7 minutes

annular eclipse (when moon doesn’t completely cover the solar disk), umbral shadow is not complete

Lunar eclipse is longer (earth is bigger)

  1. Takes hours
  2. Penubral shadow has almost no effect
  3. At totality, it looks red due to refraction through earth’s atmosphere

Sed Rocks -Con’t

October 4, 2006

It takes 2 moles to weather ignious rocks, but only 1 mole is returned by the calcium carbonate. So silcate weathering consumes CO2

Lithification process

  1. Compaction
  2. Dissolution
  3. Precipatation
  4. Recrystalization
  5. Cementation

Facies Concept

  1. Unique to where a rock forms
  2. Sediment transported to shore line
  3. sand facies is very high energy
  4. finer grain caries through sand to mud
  5. very little carries out to the carbonate faces
  6. Sand stone to mud stone to lime stone
  7. Facies can only be ontop or below ajacent facies
  8. The order in which they’re array’d gives us the sea level history (transgression or Regression)
  9. Durring regression erotion takes place

Major depositional environments

  1. Weathering and erosion (proximal) -> source rock and climate
  2. Transportation and sedimentation (updip to fluvial) -> distance, gradient, energy level (lakes vs river)
  3. Shoarline (dunes)
  4. Deltas
  5. Deep Marine
  6. rate of sink matters

Eluvial system

  1. Fan (not clay because not enough time) basement stuff (felpars)
  2. Braided (broad and wide streams)

Eolian depositis ->

  1. fine grained (weathered by wind)
  2. between proximal and distal
  3. Dunes migrate ontop of eachother

Meandering streams

  1. Big and deep
  2. flood eluvial vally
  3. deposits silt and clay
  4. going down: High energy to low energy

Delta

  1. Sudden energy drop
  2. While global sealevel is rising, the mississippi is regressing because of sedemens
  3. Opposite gradiant: find to course grain due to regression

Reaf system

  1. Limestones and dolastones (from magnesium from lagoons)
  2. Both high and low energy (high from ocean, low from lagoon)

Turbidites

  1. Clay -> courser then back to cley suddenly
  2. Graded bedding
  3. Energy of the flow highest when it gets to the site
  4. head of flow is course tail is finer.

Important stuff that didn’t fit anywhere else

  1. Lacustrine Deposits: Varves
  2. Layering caused by lakes
  3. Diagenisis -> everything not metamorphic
  4. Basement = Igneous rocks
  5. felspar becomes clay, but it takes time

Metamorphic rocks -> represent changes that occer in solid state (prior to melting)

  1. Recrystalization
  2. Phase changes
  3. Neo Crystalization
  4. Pressure solution ->the contact (touching point) is desolved between grains
  5. Deformation -> contact is not desolved
  6. Tend to find them in Precambrian sheilds and occationally folded mountain belts (due to their tectonic activity)
  7. Temp, pressure, fluids

Lithosphere goes down into mantal to stenosphere

Spectrum and Light

September 27, 2006

Hydrogen Atom

  1. Orbitals are quantized
  2. First level is ground state
  3. Each suceding orbit is higher energy
  4. The distance between orbits decreases the further you get out
  5. Spontaneous Emission -> when an electron makes a transition the electrion (atom) loses energy in the form of a photon
  6. Hydrogen Atoms have a peak at 1216A, the energy difference between first and second orbits
  7. Lyman series (transitions to or from first orbit)
  8. Balmer Series (transitions to or from higher orbits to or from 2nd) in optical spectrum

Measuring Velocity

  1. Dopler effect
  2. Tword you = blue shift
  3. away = red shift
  4. delta lambda / lambda = v /c
  5. Only measure Relitive velocity
  6. Only measures object moving along line of site

Telescope

Igneous Rocks

September 27, 2006

Processes

  1. Start off in the mantel and move out
  2. Two kinds: intrusive and extrusive
    1. Intrusive are under the crust and take long to cool (big crystals)
    2. Extrusive are volcanic and cool quickly (course)
  3. All part of the rock cycle
  4. Magma and lava – Controls
    1. we can do phase diagrams, except we flip the y-axis to represent depth
  5. Sources of heat
    1. Radiogenic decay (biggest)
    2. Impacts (meteorites)
    3. Gravitational Compression
    4. Sinking of Fe Alloys
    5. Tidal Frication
  6. To tell heat under the surface we find pressure gradiant and temp at surface and use adiabate to determain heat at depth
  7. We can cacluate preasure from gravitation
  8. Two melting curves for dry and wet (weather they contain volitiles) effecting how it melts
  9. Due to shape of curves decompression of rising magma causes it to melt
  10. For main causes of differentiation (the different make ups of igneous rocks from minerals)
    1. Differences in magma sources
    2. Partial melting (gaining bouyancy)
    3. Country rock (picking up shit on the way up), breaks off in xenoliths and melts, or melts on the sides
    4. Fractional crystalization
  11. Differentiation tends to be a comparison between high in Fe, Mg (mafic and ultramafic from the mantal from #1-2) to high Si, Al (felsyc from #3-4)
  12. Geotherm veries, average of 30*K per km (60*K in a basalt)
  13. Minerals – Bowen’s reaction series (melting points of minerals) -> olivine is high quartz is low, Plaglioclase is both
  14. Texture -> Rapid cooling is Fine-grained (aphanitic), slow cooling is Coarse grained (phaneritic)
  15. Porphyritic is a combination of aphanitic and phaneritic
  16. Distribution of igneous rocks
  17. Plate techtonic decide spreading of igneous rocks (mafic) through decompression cooling at divergant margins
  18. Subduction pulls under contental plates (fasyc) also known as a convergant margin
  19. Basaltic volcanism can happen in the contenants due to sufrace composition
  20. Caldera = colapsed volcano
  21. Snake river plane in Yellow stone demonstraits the movement of plate techtonics (the place of the volcano keeps moving)

Light

September 25, 2006

  1. Light is a form of electromagnatism
  2. Light has both Wave and Particle features (wave particle duality)
  3. Photon
    1. A Partical that carries the electromagnatic radiation
    2. Wave length: linear distance between two crests of the wave of a photon (lambda)
    3. Frequencey: Number of crests that pass over a unit of time (nu)
    4. A long wave length will have few crests over a unit of time
    5. Wave length and frequency are related by the speed of light: 3×10^5km/s or 3×10^10cm/s
    6. c = lambda * nu (where c is the speed of light)
      1. if lambda goes up then nu goes down (and vise versa)
    7. Visible light has very short wavelengths (on order of angstroms, 4000-7000)
    8. Hertz = one unit per second
    9. The energy of a photon = h*nu (where h is a constant)
    10. Spectrum
      1. Gamma (0 -> .1 A) Harmful, found in nuclear explosions, Very high frequency thus energy
      2. X-rays (.1 -> 100A) Harmful, but not in very small doses
      3. Ultraviolate (100 -> 4000A) Harmful with continued exposure
      4. Visible (4000-> 7000A) Small range from blue (4000) to red (7000)
      5. Infrared (7000A -> 1mm) Skin feels as heat
      6. Microwave (1mm-> 10cm) Like a microwave oven (which uses alot of microwave, like a bright light)
      7. Radio (10cm -> infinate) Need long wave length to get through water
    11. S
  4. Spectroscopy -> breaking up light into its components (like a prism)
    1. Using this we can plot the intensity of light as a function of wavelength
  5. Light can tell us about:
    1. Tempurature
    2. Movement
    3. Conditions
  6. Continuos spectrum (all wavelengths in a range)
    1. Stars often aproximate this
    2. Black body object (absorbs all light and reflect none, however does emit its own)
    3. Stars are blackbody because they emit light, but don’t reflect light (the moon does the exact opposite)
    4. The  characteristics of a blackbody is that its tempurature is observable from its spectrum
      1. Plots (wv vs brightness) aproximates poisson distribution
      2. As the object cools, its “peak” moves from ultraviolet to infrared
    5. Higher tempurature emitis more radiation at all wave lengths
    6. Hotter may emit more blue than red (making it look cool) but it still emits more red than the cooler (red) one
    7. Wien’s law (lambda max * T = 2.9×10^7AK)
    8. Humans are 310k so lambda max = 100,000A, making us blackbody in the infrared spectrum (which is why the military likes infrared stuff)
      1. We’re visible in the visible spectrum because we reflect light
    9. Emited by solid, liquid or pressurized gas (star)
  7. Absorption line specturm
    1. If we put a cool cloud of gas between a star and ourselves we’ll notice certain wavelengths are missing
    2. Most stars have an atmosphere around them which causes them to apear as an absorption line spectrum
  8. Emission line spectrum
    1. Put the same gas agains the background of the universe we’ll see only certain lines
    2. These lines are the same lines which were absorbed when we looked at the sun through said gas
    3. These are due to electrons absorbing photons an jumping up into higher orbitals (thus ions absorb and emit differently than once with full valiance shells)
  9. 90% of the universe is made of H, so we talk about that alot