2.8- Summary Unit 2

What you did

  • You read the Canvas Materials provided
  • You watched Instructor's Lectures and Tutorials
  • You completed assignments 1 - 4
  • You took two quizzes
  • You took the Place Name Exam
  • You will take the Unit 2 Exam

What you learned

You should use this as a Study Guide for the Unit 2 exam. The Unit 2 Exam is scheduled to open March 3 and is due March 6 . It will be worth 35 points. The questions are multiple choice, true/false and perhaps a short answer or two. There will not be any questions that include ships sinking or anything of that complexity. But understanding the concepts behind those questions will help you immensely with the exam.

  • The Inner (Terrestrial) Planets: Venus, Earth, Mars are less oblate, rotate more slowly and are more dense than the Outer Planets
  • The Outer (Jovian) Planets:  Jupiter, Saturn, Uranus, Neptune and Pluto are more oblate, rotate faster and are less dense than the Inner Planets
  • Oblateness= flattening at the poles, bulging at the Equator, due to centrifugal force
  • Density = Mass/Volume
  • Gravity: On Earth 1.0, on the moon  0.17, on Jupiter 2.54 (weight changes with gravity but not mass)
  • Facts:
    • a great circle is equal to the earth's circumference and is the shortest path between 2 points on Earth
    • The earth's circumference is about 24,900 miles
    • The latitude and longitude of Santa Rosa are 38°N, 122°W
    • The earth is approximate 70% water and 30% land
    • Declination is the location of the most intense solar radiation on any given day (eg. on June 21, the declination is 23.5°N)
  • Latitude
    • Lines connecting points of equal latitude are called parallels
    • Parallels never cross
    • There are always about 69 miles between degrees of latitude
    • Parallels cross meridians at right angles
    • All locations have a latitude between 90°N and 90°S
    • Latitude can be determined by measure the angle of Polaris (the north star) or the sun at solar noon above the horizon
  • Longitude
    • Lines connecting points of equal longitude are called meridians
    • Meridians run from pole to pole
    • Distance between meridians varies from about 69 miles at the equator to 0 miles at the poles
    • Each meridian is half of a great circle and half the circumference of the earth
    • Longitude measures distance east and west of the prime meridian
    • The prime meridian is arbitrary. Through international agreement we use the meridian running through Greenwich, England as 0° of longitude
    • Longitude can be determined by comparing the current time at port with the time aboard ship. Each hour difference equals 15° of longitude separating the locations
    • John Harrison invented the Marine Chronometer to measure time at sea
  • Seasons
    • We have seasons on earth because the earth's axis is tilted 23.5°
    • Summer Solstice: June 20/21, max solar intensity No. Hemisphere, declination of the sun 23.5°N (Tropic of Cancer), Longest day of the year  N. Hemisphere, 24 hours daylight 66.5°N to 90°N
    • Winter Solstice: December 20/21, max solar intensity in the So. Hemisphere, declination of the sun 23.5°S (Tropic of Capricorn),  shortest day of the year N. Hemisphere, 24 hours darkness 66.5°N to 90°N
    • Conditions are reversed in the Southern Hemisphere
    • Equinox: March 20/September 20, declination of the sun 0° (the equator), everywhere on earth 12 hour day, sun rises and sets at 6:00 
  • Maps
    • Small Scale: example > world map, Large Scale: example > city map
    • Mercator: a projection with great distortion, inappropriate as a display map but great for navigation
    • Isolines: connect points of equal value. Closer together = more rapid change, farther apart = more gradual change. Isolines never end and never cross
    • Contour line - isoline connecting points of equal elevation

Coming Up

In the next Unit you will be learning about Weather.

  • Insolation and Temperature
  • Pressure and Wind
  • Humidity and Precipitation