a) What is the age of the oldest oceanic crust near Rio De Janeiro, Brazil (along the east coast of
South America)? m.y. On your page-size map, place a dot labeled A showing the
approximate location of Rio De Janeiro.
b) What are the approximate latitude and longitude (to the nearest degree, and remember that latitudes
are always °N or °S, and longitudes are °E or °W) of the Fiji Islands in the central Pacific Ocean?
____
(latitude) and ___ (longitude). On your page-size map, place a dot
labeled B showing the approximate location of Fiji.
c) What is the youngest crust in the Labrador Sea? _ m.y. Please put a dot labeled C
showing the location of the youngest crust in the Labrador Sea.
Is the Labrador Sea still growing? Yes or No? ___

d) On your page-size map, please place dot D somewhere you could walk on a spreading center.
f) The Challenger Deep in the Marianas Trench is the deepest point in the world ocean (it is labelled
on the World Map – near the Philippines)? How deep is it? _(m or ft)
Place a dot labeled F (on your page-size map) showing the approximate location of Challenger Deep.
What process caused the formation of the Mariana Trench? ______

1. (3 pts) Please indicate the locations of spreading centers and trenches on the page-size copy of the
world map. Use solid lines (or blue lines) for trenches and dashed lines (or red lines) for spreading
centers.
These features delineate the major tectonic plates: please label the ten major plates on Earth
(African, Antarctic, Cocos, Eurasian, Indo-Australian, Nazca, North American, Pacific, Philippine and
South American) — just write the name of each plate on your page-size map.
2. (2 pts) Determine how fast the Southern Ocean is spreading between Australia and Antarctica:
— Remember that cm = centimeters, km = kilometers, my = millions of years, yr = years
— Remember that a RATE (speed) is equal to the DISTANCE divided by the TIME
— To convert km/my to cm/yr, just divide by 10
Step #1: First, measure the distance between Australia and Antarctica in cm on your large World Map
(not the piece of paper!):
Distance on map in cm = _
Step #2: Convert the map distance to the real distance by multiplying by the map scale (358km/cm)
Distance on Earth in kilometers (km) = _

Step #3: The age of the oldest crust near Australia and Antarctica where you measured. This is the age
of the oldest ocean floor on the line between the two points.
Time = Age of the oldest crust in millions of years = __
Step #4: Calculate the rate of opening (Rate = Distance / Time) in both km/my and cm/year.
(Remember that 1 km/my = 10 x cm/yr or 1 cm/yr = 0.1 x km/my)

Sample Solution