DOC PREVIEW
CU-Boulder GEOG 1001 - EARTH MOTIONS AND EARTH-SUN RELATIONS

This preview shows page 1-2-3 out of 8 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Part V. The Annual March of the SeasonsName: ________________________ Section: ______ Date: ____________EXERCISE A: EARTH MOTIONS AND EARTH-SUN RELATIONSREFERENCE: Textbook: Geosystems: An Introduction to Physical GeographyCh.1 Essentials of Geography and Ch.2 Solar Energy to Earth and the Seasons , or on the links related to lab A LINKS PURPOSE: The purpose of this laboratory exercise is to review the concepts of earth movements and the relationships between earth, its movements, and the sun. Earth movements and earth-sun relationships are critical to understanding why and when we experience day or night and summer or winter. They have direct influence on the seasons and climates experienced at different locations on earth and, indirectly, they influence the distribution of vegetation and fauna on earth a well.KEY TERMS AND CONCEPTS: *Hint: Be able to define and compare-contrast each of these terms for your exams!equator rotationArctic circle rotational and angular velocityAntarctic circle revolutionTropic of Cancer perihelionTropic of Capricorn apheliongreat circle axial tilt (inclination)small circle axial parallelismlatitude polaritylongitude circle of illumination parallels solsticemeridians equinoxPart I. Earth - Where are we?The earth is the third of nine planets in our solar system. The shape of earth is not perfectly spheroid. It is oblate-spheroid, meaning it is slightly flattened pole-to-pole making the equator the largest circumference on earth. To help us understand and communicate about positions on earth, a grid system has been developed to identify specific locations. Lines of latitude and longitude make up the grid. Lines of latitude mark positions north and south of the equator. Latitudes are parallel to each other and are also called “parallels”. Important parallels are the equator, Tropics of Cancer and Capricorn, Arctic and Antarctic Circles and north and south poles. Lines of longitude are also called “meridians”. They mark positions east and west of the “prime meridian” which has a longitude of 0° and runs through Greenwich, England.1Part II. Earth MotionThe motion of earth turning on its axis is termed rotation. The motion of earth moving around the sun is termed revolution. The two motions are concurrent but have entirely different effects on the earth and on life on earth.1. Fill in the following information about earth and its motions:(a) One rotation of the earth takes _____ hour(s) or ______ day(s).(b) The earth revolves around the __________.(c) The earth makes _____ revolution(s) per year.(d) The earth is tilted on its axis_______ degrees from perpendicular.(e) Label (name and degrees of latitude) the 5 important parallels in Figure 1 (p.7).2. Listed below are 8 phenomena concerning earth environment. They are in no particular order, but they can be attributed to either earth rotation or revolution. Beside each phenomenon indicate whether it is due to rotation or revolution:Time of year __________________________ Time of day ________________Seasons ______________________________ July 4 _____________________Direction (E/W) of sunrise _________________ Day and Night ______________Noon ________________________________ Midnight ___________________Part III. Earth Rotation1. Two ways to describe the direction of earth’s rotation are:____________________ when looking down at the North Pole__________________________ when looking at the equator2. The circumference of the earth at the equator is about 24,900 miles or 40,075 km. Since the earth makes one rotation in 24 hours, a person at the equator moves with the earth at what rotational velocity? (HINT: rotational velocity = distance ÷ time)__________ miles per hour__________ km per hour23. A person anywhere on earth other than the equator travels at a lesser speed. Why?4. At the latitude of Boulder (40°N 105°W), one degree of longitude is approximately 53 miles or 85 km. At what velocity is a person in Boulder moving due to earth’s rotation?________ miles per hour_________ km per hour5. What other latitude would have the same velocity, in km per hour, as Boulder?6. Rotation velocity is distance traveled over time. Questions (2) to (5) have demonstrated that places on earth with different latitudes have different rotational velocities. However, they all have the same angular velocity. Angular velocity is the number of degrees of rotation with time. All latitudes rotate 360 degrees in 24 hours and, therefore, they have an angular velocity of:__________________ degrees per hour7. Calculate the rotation velocity for each of the following latitudes:(HINT: You need the angular velocity in Question (6) to calculate rotation velocity)LatitudeApprox. Length of 1° LongitudeRotational Velocity(N or S) (miles) (km) (miles/hour) (km/hour)80°60°40°20°3Part IV. Earth’s Orbit of Revolution1. The earth’s orbit around the sun is not a perfect circle; it is elliptical. The closest distance from the sun to earth is called perihelion and the largest distance is called aphelion (Figure 2, p.8).2. The date (month and day) of perihelion is ___________ and the date of aphelion is ____________. To summarize the distance between the earth and the sun, the distance is increasing from the months of ____________ to _____________ and the distance is decreasing from the months of ____________ to ____________. The average distance from the sun to earth is ____________ miles or _______________ km and the variation from perihelion to aphelion is _______________ km.Part V. The Annual March of the Seasons1. Figure 2 shows four key positions of the earth as it moves around the sun. Each position marks a change in seasons. Indicate the date (month and day) and the name of each of the four positions.2. There are three important features of Figure 2 which account for the change of seasons:i. The earth revolves around the sun in a counter clockwise direction.ii. The earth is tilted relative to its orbital path, called “axial tilt”.iii. The earth’s tilt is always pointing in the same direction, called “axial parallelism” or “polarity”.Day length also varies throughout the year and with the change of seasons. The “circle of illumination” is the boundary that divides day and night. In Figure 2, it indicates the length of day (white) relative to the length of night (shaded) at each of the four positions.Based on these facts,


View Full Document

CU-Boulder GEOG 1001 - EARTH MOTIONS AND EARTH-SUN RELATIONS

Download EARTH MOTIONS AND EARTH-SUN RELATIONS
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view EARTH MOTIONS AND EARTH-SUN RELATIONS and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view EARTH MOTIONS AND EARTH-SUN RELATIONS 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?