Longitude and Latitude Latitude- East and West Longitude- North and South

Locating points on the globe                                            "OK! If we put both the latitude lines and the longitude lines together on the sphere, what've we got? A GRID! Now we can locate places by giving their latitude and longitude. For example, the latitude of the blue dot is 40° N, and its longitude is 60° W. I've shown latitudes at 10 degree intervals and longitude at 15 degree intervals!)"

Quiz!!! What you need to do, is give me the latitude and longitude of the red, orange, green and pink dots! As you may recall, the latitude lines are shown for every 10 degrees, starting at the equator; the longitude lines are shown for every 15 degrees, starting at the prime meridian. And don't forget, both latitude and longitude are expressed as a certain number of degrees plus a direction - N, S, E or W Red- Orange- Green- Pink- 60 deg. N, 30 deg .W 10 deg. S, 15 deg. W 20 deg. N, 45 deg .E 10 deg. S, 30 deg .E

Actual Distances- are we there yet? Tell me, how far is it in miles along the equator between two degrees of longitude, say from 15° W to 16° W?" "I can answer that! I seem to remember that the circumference of the earth along the equator is roughly 24,901.92 miles (heh heh!). Well, there's 360 degrees in a circle, so if we divide 24,901.92 miles by 360 degrees, we get 69.172 miles per degree! How's that! And furthermore, the distance between two lines of latitude, from 0 degrees to 1 degree north, is also 69.2 miles - because it's also 1/360th of the circumference of the earth!" "

Some Questions!!!! But what happens to the distance between lines of longitude as you go north or south away from the equator?!" Let's look at the diagram! I can see that the lines of longitude get closer and closer together towards the poles! At the equator, the distance between 15 and 30 degrees W longitude is quite a lot! But as you follow those two longitude lines towards the poles, the distance between them shrinks down to zero! All the lines of longitude actually meet at the poles! So really, 'longitude' has no meaning when you're at the poles! I don't think I'm gonna go to the poles! I'd be nowhere! And everywhere!"

What about Latitude distance? At least latitude still has meaning, even at the poles! Notice that the distance between lines of latitude remains the same!"

Where are we? Well, suppose I told you the location of a place was 5 degrees N latitude and 71 degrees W longitude. Then you'd know where it was exactly. But suppose I told you its latitude was between 5 and 6 degrees N and its longitude was between 71 and 72 degrees W. Well, since degrees of latitude are about 69 miles apart, and degrees of longitude near the equator are maybe 60 miles or so apart, you wouldn't know exactly where the place was located, would you?

Where are we??? Let's start off with just degrees and minutes! Look at points A, E and J! I've listed their latitudes and longitudes in degrees and minutes in the table below!" POINT LOCATION A lat. 5° 45' N; long. 71° 50' W E lat. 5° 07' N; long. 71° 50' W J lat. 5° 30' N; long. 72° 00' W Now it's your turn. Look at the diagram and give me the locations of the rest of the points in degrees and minutes of latitude and longitude!

Getting closer Now we'll focus on seconds! I've given you another table! This one tells you the locations of A, B and C in degrees, minutes and seconds of latitude and longitude! POINT LOCATION A lat. 5° 59' 45" N; long. 71° 00' 45" W B lat. 5° 59' 09" N; long. 71° 01' 00" W C lat. 5° 59' 30" N; long. 71° 00' 00" W Look at the diagram and give me the locations of the rest of the points in degrees, minutes and seconds of latitude and longitude

Finally some distances Let's talk again about distance in miles! The greatest distance there can be between one degree and the next is about 69 miles! So, roughly speaking, what's the greatest distance there can be between one minute and the next? And between one second and the next? If one degree is 69 miles, and one degree = 60 minutes, then one minute is one-sixtieth of 69 miles! I'd say that's roughly one mile! Or would you want me to say 1.15 miles?" And if one minute is roughly 1 mile, and there are 60 seconds in one minute, then one second is roughly one sixtieth of one mile, which is what? There are 5280 feet in a mile, so I guess I could call that roughly 6000 feet! So one sixtieth of 6000 feet is roughly 100 feet! 1 Degree = 69 miles 1Minute =1 mile 1 Second= 100 feet