oceanography lab midterm review notes

Scientific Method Steps

• question

• research

• hypothesis

• test / experiment

• observe and record

• conclusion

• report results

data vs measurements?

• data: the collection of observations and measurements

  • data: plural “data are—”

• measurement: the dimensions,capacity, or amount of something represented by a number, aka what you’re measuring.

  • measurements make up data

Metric Conversion Chart

• kilo- 1000 units

• hecto- 100 units

• deka- 10 units

• basic unit

• Deci- .1 units

• centi- .01 units

• milli- .001 units

• converting to smaller unit x10 or move decimal point to the right

• convert to larger unit /10 or move decimal to the left

calculating volume = length x width x height (units—> mm³)

• Continental drift

  • alfred wegner

  • Pangea — ocean named: panthalassa

  • evidence

    • puzzle like fit

    • matching rock sequences/ mountain chains

    • glacial deposits

    • org distribution

    • fossils

    • plate tectonics

• Plate Boundaries

  • Divergent

    • spreading apart

    • creation of new crust

  • Convergent

    • plates come together

    • destruction of crust

  • Transform

    • go past eachother

    • crust neither destroyed nor created

  • Divergent features

    • Mid-ocean ridge

      • Rift valley

    • New ocean floor created 

    • Sea floor spreading 

  • convergent boundary types

    • Oceanic-contenintal 

      • Oceanic is subducted, bc its denser

    • Oceanic-oceanic 

      • Older oceanic, bc older is denser

    • Continental-continental 

  • Convergent features 

    • O-C: trench, volcanic arc on land 

    • O-O: trench, volcanic arc as island

    • C-C: mountains

• Convection cells 

  • Idealized representation of plate tectonics and seafloor spreading 

  • vertical transfer of heat by the circulation of a gas, liquid or a plastic solid

• Measuring rate of movement using: V= D/T

  • Velocity (rate of movement) = Distance / Time

Ocean sediments 

• classification by grain size and composition

• Wentworth scale 

  • largest= boulders

  • smallest= clay 

• Sediment sorting 

  • Measure of grain size uniformity

  • Well sorted: Same

  • Poorly sorted: all different

  • Moderately sorted: most common 

• Deposit types 

  • Biogenic- biologically derived

    • Siliceous ooze

    • Calcareous ooze 

      • > or = to 30% of bio material 

  • Terrigenous 

    • Derived from land, weathering and erosion of rocks 

  • Pelagic - formed/deposited in open ocean 

    • Lithogenous 

    • Cosmogenous - derived from space

    • Authigenic- precipitation of chemicals 

• Settling velocity 

  • Depends on :size & density of particle + temperature & viscosity of water. 

    • Larger rocks settle faster, size and density of particles is the biggest factor 

    • Increase in temp = less viscosity ( vise versa )

    • Increase in viscosity = harder to travel through 

  • V= D/T  (cm/sec) 

Salinity 

• Salinity is the sum of all dissolved ions 

  • (positive and negative charged elements) in the water, expressed as parts per thousand (%another lil circle ) (etc...) of seawater

• Methods of measuring 

  • Evaporation 

    • “Poor mans” way , very outdated, slow, and not accurate , (g/kg)

  • Refractometer (%o)

    • More salt= refract more

  • Hydrometer (%o)

    • Density increases with increasing salinity 

  • Conductivity (PSU) 

    • PSU= practical salinity unit. 

    • Most accurate, easy to use, instant reading, tool used: conductivity meter

    •  More salts= stronger electrical current

• Evaporation vs precipitation

  • Evaporation increases salinity 

  • Precipitation decreases salinity 

• Salinity units

  • g/kg

  • Ppt (%o)

  • PSU 

Buffering 

• buffering= resistance to change (in pH) 

• Self regulation process in ocean 

• Ocean buffer sys = The Carbonate System 

• pH 

  • Oceans pH = 7.6-8.4 , avg. 8.1, slightly basic

  • Measure of acidity (0-5 range) or alkalinity( or basic 8-14 range) of a solution and amount of H+ ions in the solution

  • Acidic solutions = more H^+ ions

  • Basic solutions = more (OH^-) ions 

  • Seawater is slightly alkaline 

  • pH of ocean is extremely important for living organisms there

  • Affected by : dissolved CO2 

• Lab equipment used: graduated cylinder, beaker, pH meter/ probe, flask, 

• Acids used: Hydrocholoric acid (HCl) 

• Solutions used: ocean water

Lab equipment 

• Graduated cylinder

• Beaker

• Erlenmeyer flask