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EEn.2.1.2
Predict the locations of volcanoes, earthquakes, and faultsbased on information contained in a variety of maps.
Before we begin our lesson, let’s practice reviewusing an instrument that many mathematiciansuse called a protractor.
As you study Earth Science and mapping, you’llsee how knowledge of angles is essential toyour lesson!
Let’s start by going to the following website:
http://www.amblesideprimary.com//ambleweb/mentalmaths/protractor.html
•Cartographers use an imaginary grid of parallel linesand vertical lines to locate points on Earth.
•The equator circles Earth halfway between the northand south poles separating Earth into two equalhalves called the northern hemisphere and thesouthern hemisphere.
•Cartography is the science of mapmaking.
Latitude and Longitude
•For thousands of years, people have used mapsto define borders and to find places.
Latitude and Longitude
Latitude
•Lines of latitude are lines running parallel tothe equator.
Latitude and Longitude
•Latitude is the distance indegrees north or south ofthe equator.
00 Latitude (Equator)
The area north of theequator is called theNorthern Hemisphere.
The area south of theequator is called theSouthern Hemisphere.
00 Latitude (Equator)
900 N
Latitude
900 SLatitude
300 N Latitude
600 N Latitude
300 S Latitude
600 S Latitude
Angle of
Latitude
–Each degree of latitude is equivalent to about111 km (almost 70 miles) on Earth’s surface.
–To locate positions on Earth more precisely, cartographers breakdown degrees of latitude into 60 smaller units, called minutes(´).
–A minute of latitude can be further divided into seconds (´´).
–Longitude is also divided into degrees, minutes, and seconds.
Longitude
•To locate positions in east and west directions,cartographers use lines of longitude, also knownas meridians.
Latitude and Longitude
Longitude is the distance indegrees east or west of theprime meridian.
The prime meridian,representing 0° longitude, isthe reference point forlongitude.
Longitude
Latitude and Longitude
The area Eastof the PrimeMeridian isknown as theEasternHemisphere.
Longitude
Latitude and Longitude
```
The areaWest of thePrimeMeridian isknown asthe WesternHemisphere.
•Points west of the prime meridian are
numbered from 0° to 180° west longitude (W).
•Points east of the primemeridian are numbered from0° to 180° east longitude (E).
Longitude
–Lines of longitude are notparallel; they are largesemicircles that extendvertically from pole topole.
Longitude
The distance
between
Lines of
Longitude vary.
The distancebetween linesof longitudeare greatestnear theequator andsmallest nearthe poles.
Use your laptop to complete themini-lab on page 29. You may workin the work-groups you were in onFriday.
Use the website:
http://www.worldatlas.com
Time Zones
Latitude and Longitude
15o
45o
75o
105o
135o
165o
195o
225o
255o
285o
315o
345o
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Time Zones
•Because Earth takes about 24 hours to rotate once on its axis, it isdivided into 24 times zones, each representing a different hour.
Latitude and Longitude
Time Zones
•Each time zone is 15° wide, correspondingroughly to lines of longitude.
Latitude and Longitude
•Time zone boundaries have been adjusted in localareas for convenience.
Time Zones
•There are sixdifferent timezones in theUnited States.
Latitude and Longitude
Note: Each dayends (and thenext begins atthe stroke ofmidnight.
* Each time zone experiences this transition from one day to thenext…with the calendar advancing toward midnight.
Time Zones
Calendar Dates
Latitude and Longitude
–Each time you travel through a time zone, you gain or losetime, eventually gaining or losing an entire day.
–The International Date Line, or 180° meridian, serves as thetransition line for calendar days.
Time Zones
Calendar Dates
Latitude and Longitude
–Traveling west across the International Date Line, you wouldadvance your calendar one day.
–Traveling east, you would move your calendar back one day.
N
S
E
W
Answer Questions 1-4 on thesection
assessment on page 31
Types of Maps
•Maps are flat models of a three-dimensionalobject, Earth.
•All flat maps distort to some degree either the shapesor the areas of landmasses.
•Cartographers use projections to make maps.
•A map projection is made by transferring points andlines on a globe’s surface onto a sheetof paper.
A conic projection is a map madeby projecting points and lines froma globe onto a cone.
•The cone touches the globeat a particular line of latitudealong which there is very littledistortion in the areas or shapesof landmasses.
•Distortion is evident nearthe top and bottom of theprojection.
A gnomonic projection is amap made by projectingpoints and lines from a globeonto a piece of paper thattouches the globe at a singlepoint.
•Gnomonic projectionsdistort direction anddistance betweenlandmasses.
•Gnomonic projections are useful in plotting long-distance trips byair or sea.
A Mercator projection is a map that has parallellines of latitude and longitude.
Topographic maps aredetailed maps showingthe elevations of hills andvalleys of an area.
–A contour line connectspoints of equalelevation.
Topographic Maps
Contour Intervals
–Topographic maps use contour lines to show changes inelevation.
–The contour interval is the differencein elevation between twoside-by-side contour lines.
–The contour intervalis dependent onthe terrain.
Topographic Maps
Depression Contour Lines
–Depression contour lines are used to represent features thatare lower than the surrounding area.
–On a map, depressioncontour lines have hachures,or short lines at right anglesto the contour line that pointtoward the lower elevation,to indicate depressions.
