Map Skills
Latitude & Longitude
When you plot points in math class you have two coordinates, an X and a Y (X, Y). The X axis allows you to plot points horizontally and the Y axis allows you to plot points vertically. If this is something that you have done before, you already have the basis for plotting points of latitude and longitude.
When people want to find a location they use a map. In the 21st century, our maps are digital. Google Maps, Waze, and other mapping apps use GPS (Global Potitioning System) to find coordinates on our planet. These coordinates have a horizontal position (latitude) and a vertical position (longitude) just like the grid in math class. The Earth's grid is imaginary but it doesn't stop the world from using it.
Lines of Latitude
One of the most famous latitude lines is the Equator at 0º latitude. Latitude lines run horizontally but measure points north and south. The picture below shows latitude lines. They measure from 0 - 180º north and 0 - 180º south. All latitude lines are equidistant parallel lines, meaning that they go up by the same amount. In this example each line goes up by 15º. The arrow is at 15º North.
In this picture when traveling north of the Equator, you are in the northern hemisphere, so 0º - 180º would be labeled north. When traveling south of the Equator, you are in the southern hemisphere, so 0º - 180º would be labeled south. Latitude lines are also known as parallels and are always 1st when writing coordinates (15ºN, 20ºW)
Lines of Longitude
One of the most famous longitude lines is the Prime Meridian at 0º longitude. Longitude lines run vertically (the LONG way) but measure points east and west. The picture below shows longitude lines. They measure from 0 - 90º east and 0 - 90º west. All longitude lines meet at the north and south poles. In this example each line goes up by 10º. The arrow is at 20º West.
In this picture, when traveling left of the Prime Meridian, you are in the western hemisphere so 0º - 90º would be labeled west. When traveling right of the Prime Meridian, you are in the eastern hemisphere so 0º - 90º would be labeled east. Longitude lines are also known as meridians and are always 2nd when writing coordinates (15ºN, 20ºW)
Time Zones
We know that the Earth rotates on its axis, this is what gives us day and night but why don't we have the same time arond the world? If we all the same time (let's say 8am) we would have daylight in New York when it is night time in Taiwan. It would be weird. Time zones allow us to have morning hours when it is dayliight (for most of the world).
A time zone is a width of longitude that has the same time. We know that there are 360º in a circle and the Earth is circular in shape. If the Earth rotates 15º an hour how many time zones do we have? *Hint* divide 360 by 15.
360 ÷ 15 = 24. There are 24 time zone on Earth.
Travel east, your time will increase. Travel west, your time is less.
The United States lies across six time zones. They are: Eastern (EST), Central (CST), Mountain (MST), Pacific (PST), Alaska, and Hawai'i.
If it is 8am (start of school) in New York (NY)what time would it be in California (CA). CA is 3 time zones west of NY so the time is 3 hours less. 5am.
Topography refers to the shape and physical features on Earth's surface. Ex: The height of a mountain or the depth of a lake. Topographic maps use contour lines to show the elevation or depression of physical features on Earth.
Contour lines
are lines that connect equal points of elevation. The contour interval is how much each line goes up by. The closer the countour lines are on a map, the steeper the elevation. **You can tell the direction a river flows by looking at the contour lines. The lines will form a 'V' or 'U' shape around the river. The river flows in the opposite direction of the point of the 'V'. (You can also tell using the numbers on the map. Water doesn't flow against gravity so find the direction where the numbers are decreasing.
In this picture you can see that there are 5 contour lines from 100m to 200m. Each line goes up by 20m so the contour interval is 20m.
In this picture you can see that the contour line are closer together where the arrow is. This is an indicator that the area is steeper there than it is on the rest of the map.
In this picture you can see the 'U' shape of the contour lines around the river. The top of the 'U' faces SW so the river is flowing NE.
Hachures
To show depression you use depressioncontour lines or hachures. These lines are used to represent features that are lower than their surrounding areas. They have the same contour interval that the rest of the map is using only instead of going in a positive direction, you go in a negative direction. If the interval is 10 meters, you would subtract 10 meters for every depression line that you see. (Depression lines are contour lines with hachures or short lines at right angles all the way around it.)
In the picture below the yellow arrowpoints to an elevation of 120m. The hachure next to it (red arrow) would also be 120m and then the elevation would start to decrease -20m. The contour line around 'A' would be 80m. This could represent a lake or a dip in the mountain.
Topographic map on paper
Topographic Map App
