The locations of earthquake epicenters are shown with letters. The epicenter is the spot on the surface of the earth that lies above the focus. The focus is the place along the fault where the 1st ground movement has occurred). Three categories of earthquakes can be identified: "S" - shallow earthquakes with focus closer to the surface (0-45 miles deep) "I" - intermediate earthquakes (45-125 deep) "D"-deep earthquakes (125-300 miles deep) An active volcano is symbolized as a shaded triangle. A continent or island has a dotted pattern within a bold-faced line or circle. The ages of volcanic ocean floor rocks are marked as circled numbers on the figure, in millions of years. I. The first step of the lab is to DRAW IN THE APPROXIMATE PLATE BOUNDARIES as indicated by the earthquake activity on the map. ***Hints: a) Look at the pattern of earthquakes. For example, subduction produces a pattern of deeper and deeper earthquakes as one plate plunges beneath the other. b) The age pattern of ocean floor basaltic rocks suggest the location where new ocean floor is being created at a mid-ocean ridge. c) Volcanic activity may be associated with subduction, spreading centers, or mantle plumes. Use the following symbols when marking in the plate boundaries. Note: there are no transform boundaries. Convergent Boundary: *Map symbol to be used: LO GO S S 00 to I H D D H D S H D D 00 H H D S (33) S S S 00 I S I S D I S 00 S DA H S I S S (70) D DII S S D D I H S S D I Scale: 1" 500 miles (1 cm = 300 km) S S S 00 (14) (45) I D S (10) S (35) 00 00 S S 00 H S S 100 S D S (25) S S S S (20) 7 (83) (63) S D D D 00 S S S S CA S S S S D D S S I S S S 00 (33 B (32) S S CO Question 1 How many different plates are clearly shown on the map? one plate two plates three plates four plates Question 2 2.5 pts 2.5 pts How many of the plates on the map consist entirely of ocean floor (or ocean floor with islands)? one two three four Question 3 2.5 pts Which portion of the map has mountains similar to the Andes of South America, coastal volcanic mountains which are sitting on the edge of a continent? O towards the northeast in the center towards the southwest Question 4 What type of plate boundary exists at the location you chose in #3? convergent, ocean to ocean convergent, ocean to continent convergent, continent to continent divergent 2.5 pts