Oceanography 001                                                                              West Valley College

R. Lopez                                                                                             


Study Questions 1: Maps and Oceanography


1)      Latitude is the angular distance measured from the _____________________?


2)      All latitude lines are great circles.  True or False?


3)      In the night sky you notice that the North Star (Polaris) makes a 35° angle with the horizon.  A) What does this tell you in terms of your position on the planet?  B) What hemisphere (north or south of equator) would you be in?





4)      All longitude lines (meridians) are great circles.  True or False?


5)      The Prime Meridian passes through what town in England? And, what is the significance of the Prime Meridian?


6)      Longitude is the angular distance measured from the _____________________?


7)      What angular distance from the Prime Meridian is the International Dateline?


8)      Your chronometer is set for GMT.  At high noon at your meridian or present location it is 5PM GMT.  What is your longitude?



9)      What is your longitude when your chronometer reads 8AM GMT when it is noon at your meridian?



10)  You measure an angle of 21° between Polaris and your local horizon with a sextant.  High noon at your meridian is 10:30PM GMT.  What is your latitude and longitude?





11)  Look on pages 38-39 in lab text.  Where are you from your answer to the question above?


12)  Recall that 1° of latitude on a Great Circle (meridian) is 111 km or 69 miles.  While driving to Portland, Oregon, from the south, you pass a sign saying 45° N latitude.  Calculate your distance to the equator in kilometers and in miles.





13)  From the question above, how far away in terms of kilometers and miles is Portland, Oregon from the North Pole?




14)  What are Map Projections?



15)  Be able to identify the Mercator map projection.



16)  When the representative fraction of a chart reads 1:24,000, what does this mean?



17)  What is Bathymetry?




18)  What are soundings and how are they measured?




19)  What is a bathymetric chart?



20)  Bathymetric profiles are “side-ways” views or cross-sectional views of the sea floor bathymetry.  True or False?



21)  Contour lines connect points of equal elevations.  True or False?



22)  What is contour interval and index contour?




23)  When contour lines cross valleys, they form a distinctive “V” shaped patter. In which direction does this “V” pattern point, up slope or down slope?