Earth Science Regents Review

Unit 1

_________________Parallel linesRun east to westMeasures distances

north or southReference line is the

equatorA.k.a. parallels0-90o

__________________

Lines that meet at the poles

Run north to southMeasures distances

east or westReference line is the

prime meridianA.k.a. meridians0-180o

3) What is the North Star? How is it used in navigation?

3) What is the North Star? How is it used in navigation?

The altitude of Polaris is equal to the latitude.

                                                                 

                        

What is the international date line?

What is the international date line?

It is the 180 degree line of longitude that separates the eastern and western hemispheres.

Summary: Summary: What is the latitude for these locations?

66.5oN 42oN

Aim: How do we break down degrees into minutes?

Aim: How do we break down degrees into minutes?

42o00’

43o00’

42o30’42o15’

42o55’

Montauk

1) How fast does the earth spin?

The earth does one 360 degree spin every 24 hours so:

360 degrees/ 24 hours=

15 degrees/hour

3) What is Greenwich Mean Time?

This is the time on the prime meridian where all of the world sets its time

4) If you are west of the Prime Meridian your time is ____________, but if you are east then your time is ______________ because__________________________________________________________________.

Earth rotates from west to east sothe sun hits the east first

5) How do we find longitude using difference in time?

Step 1: Find the difference in time in hours

Step 2: Multiply by 15 Step 3: Local time is

earlier=West Local time is later=East

2) What happens to elevation inside of a contour line?

The elevation increases inside of the line.

6080

3) How do you find the contour interval?

Subtract two contour index lines and divide by the number of hops.

15 FT

100 FT

4) When drawing contour lines what two things must they either do?

Connect into a circle

Touch the edge of the map

5) How do you figure out the highest possible elevation on

a topographic map? Figure out

the value of the next line then subtract 1.

59 FT

79 FT

6) How do you figure out the lowest possible elevation between two contour lines?

Look at the lowest adjacent line then add 1.

11 FT

31 FT

7) What happens to a contour line when it crosses a river?

The lines bend into a “V” and the river flows opposite the point of the “V”.

8) How do you know if the gradient is steep?

The closer the contour lines, the steeper the gradient.

BLINES ARE CLOSER

9) What are some ways to know which way is up on a topographic map?

Higher elevations The point of the “V” points up

10) What do hachure lines represent?

They show a hole or depresssion.

59-41 FT

19-1 FT

11) Why can’t two contour lines cross?

One point can’t have TWO elevations.

Gradient

Change in field value/Distance If the land changed from a height of 50 m

to a height of 150 m over a distance of 25 km what is the gradient?

150 m – 50 m/25 km 100 m / 25 km 4.0 m/km

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100 ft

1699 ft

7.5 milesEast

Contour lines bend upstream

Change in field value/distance

1500 ft – 1000 ft/2 miles

250 ft/mi