MARS 120
Week 1 Pre-lab exercise
Maps and Charts
Due at the beginning of lab
Provide answers on a Scantron form
GEOGRAPHY OF THE WORLDS OCEANS Using the maps of the world’s oceans
on the inside front cover and on page 551 (Appendix II) in Thurman & Trujillo, answer
the following questions:
1) Which ocean has the greatest number of trenches?
a) Pacific
b) Atlantic
c) Indian
d) Arctic
e) Southern
2) What ocean basin has a few trenches, but not many?
a) Pacific
b) Atlantic
c) Indian
3) Which ocean basin has no trenches?
a) Pacific
b) Atlantic
c) Arctic
d) Southern
e) Mediterranean
4) Which ocean basin has a centered ridge?
a) Pacific
b) Arctic
c) Southern
d) Atlantic
e) Mediterranean
5) Which ocean basin has a ridge that is not centered?
a) Pacific
b) Atlantic
c) Southern
d) Mediterranean
6) What ocean basin has narrow continental margins?
a) Mediterranean
b)
c)
d)
e)
Atlantic
Arctic
Pacific
Southern
7) What ocean basin has wide continental margins?
a) Pacific
b) Indian
c) Atlantic
8) What ocean basin has the greatest number of oceanic plateaus, seamounts and abyssal
hills?
a) Atlantic
b) Indian
c) Mediterranean
d) Arctic
e) Pacific
9) One place in the world where a mid-ocean ridge rises above sea level is:
a) Romache Fracture Zone
b) Aleutian Islands
c) Iceland
d) Madagascar
e) Hawaii
10) Fracture zones are oriented with respect to the mid-ocean ridges
a) parallel
b) perpendicular
c) 45o angle
d) many random angles
MARS 120
Week 1
Maps and Charts
Objectives:
1. to gain experience at reading maps and bathymetric charts
2. to become familiar with the depth range and average depth of the
oceans
3. to become familiar with the topographic features of the sea floor
4. to be able to locate specific features of the ocean floor
Part 1 GEOGRAPHY OF THE OCEAN BASINS
1) The class will be divided into 5 groups. Each group will be assigned one of the
following ocean basins: North Atlantic, South Atlantic, North Pacific, South Pacific,
Indian
2) Your goal is to present the results of your group discussion to the entire class. You
can use what ever resources are available in the classroom: maps, globes, white
board and/or smartboard to support your presentation. Describe the following
features of your assigned ocean:
a) surface area
i) approximate north-south distance, in km
ii) approximate east-west distance, in km
iii) approximate area in km2
iv) general shape (round, square, rectangular, oval)
b) bathymetry
i) typical depth, in m
ii) deepest depth, in m
iii) typical depth of shallow features, in m
iv) approximate portion of the basin that is smooth and nearly uniform depth
v) approximate portion of the basin that has irregular depth
c) locations and names of landforms observed in the basin
i) ridges
ii) trenches
iii) seamounts
iv) abyssal plains
v) fracture zones
vi) island chains
d) type and extent of continental margins
i) active or passive
ii) narrow or wide
iii) fed by large rivers (or not)
iv) continuous and smooth or serrated by submarine canyons
e) where are the adjacent sea and connections to other oceans
f) How would you go about investigating a-e? In other words, can observations of
the features described in a-e best be accomplished by using satellite observations?
Surface ship? Manned submersible? Scuba? Something else? You can use
Thurman and Turjillo to find out about various methods of observing geographic
and geologic features of the ocean basins.
Part 2 Contouring
Exercise 2. Contour the salinity in the Atlantic Ocean from 30oS Latitude to Antarctica,
and from the surface to the bottom, along 50o East Longitude. Indicate how many
distinct water masses of water are present in the ocean. Use a contour interval of 0.5
units. All values are in o/oo, part per thousand total salinity.
latitude
60oS
30oS
40oS
50oS
depth
500 m
36.2
34.4
34.3
33.5
33.3
33.8
33.5
33.5
35.5
34.0
34.5
35.5
35.5
35.6
35.6
35.6
35.7
35.6
35.7
35.65
35.5
35.6
35.6
35.4
35.6
35.5
35.3
35.5
35.5
35.45
34.6
34.5
34.4
1000 m
2000 m
3000 m
4000 m
34.6
34.4
34.4
Part 3 Bathymetric charts
1) The class will be divided into 5 groups. Two groups will be given the chart
named Approaches to San Diego Bay. Three groups will be given the chart
named San Diego to Santa Rosa Island
2) Your goal is to determine the ships track for a research expedition. Be prepared
to present your ships track results to the entire class.
3) If you have San Diego to Santa Rosa Island:
a. You are leaving port from San Diego. Your ships Captain will navigate
out of the harbor, but once you are past the jetties off Point Loma, you
need to give the Captain way points and compass bearings between way
points for you sampling plan.
b. You want to collect sea floor sediment samples from the following places:
i. the deepest area of San Clemente Basin
ii. the deepest are of San Nicholas Basin between San Clemente and
San Nicholas Islands (but you are not allowed to sample in the
restricted Explosives Dumping Areas)
iii. the shallow area near Osborn Bank
c. Figure out a ships track by finding way point latitude and longitude and
the compass bearings needed to drive the ship from San Diego to each of
the sampling stations and back to San Diego.
4) If you have Approaches to San Diego Bay:
a. You are leaving port from San Diego. Your ships Captain will navigate
out of the harbor, but once you are past the jetties off Point Loma, you
need to give the Captain way points and compass bearings between way
points for you sampling plan.
b. You want to collect sea floor sediment samples from the following places:
i. the head and the mouth of Coronado Canyon
ii. the deepest area to the north west of Coronado Canyon (but you
are not allowed to collect sediment samples in the restricted
Explosives Dumping Area)
iii. the shallow are to the west of site you choose to sample to the
north west of Coronado Canyon
c. Figure out a ships track by finding way point latitude and longitude and
the compass bearings needed to drive the ship from San Diego to each of
the sampling stations and back to San Diego.