Oceanography I
Professor Graus
Due: 30 April 2002
by OCEAN 6: Vonne (Shavonne L. Marshall
), Tina , Paul, Erik (Erik Fossum), Drew (Charles Rawls), Dianne
(Dianne Mollica), Cassi (was sick)
Wallops
Island Field Trip Report
Introduction and Methods
On April 14th, 2002, a class embarked on an oceanography field trip to
Chincoteague and its surrounding waters. The boat left shore at approximately
1 PM EST from Wallops Island. The trip included two stops. The first
stop was located near Chico Point, which can be located out in the open
ocean. The second location was located in Cockle Creek and was shallower.
Cockle Creek can be considered a near-shore location.
Located behind the Assateague Barrier Island, the area is protected from
regular oceanic affects. This provides an abundance of fish,
shellfish, and other various marine resources. The trip involved
taking measurements at the two locations. These measurements allowed
for the group to make observations and draw conclusions. The following
is a short summary of the test data given. Both maps, data sheets,
and other forms of information will be attached in the appendix.
To provide some background of the area the group toured, a summary of marine
environment in the Wallops Island/Chincoteague area will be discussed first.
Methods
Many methods of data collection were used during the trip. The first
step, at each location, was to take water samples from various depths.
A Van Dorn Bottle was used to collect
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samples
from surface, middle, and deep-water depths. The next step was to
measure the temperature as soon as possible because once the test sample
was out of the water; its temperature could be affected by outside sources.
A thermometer was used to take the temperature. After recording the
temperature, a refractometer was used to measure the salinity of the seawater
samples. It was a very simple process that involved dropping a small
amount of test water onto the refractometer and looking through an eye
slot to view the refractive index and the salinity. Another test
that was done down in the cabin was to test the water’s pH. A pH
meter was the instrument used to do this and the process was very quick
and simple.
Once the cabin tests were completed, the next step was to test for the
extinction depth. A secchi disk, which is a round white weight attached
to a rope, was dropped into the water until it was no longer viewable by
the human eye. The depth
was measured in meters, and then
multiplied by a constant (2.7) to obtain the photic zone depth, which is
the depth at which only 1% of light still manages to reach. Once
this test was completed, the final step step was to use a current cross
to measure the current speed and a compass to measure the current direction.
The cross was dropped into the water and allowed to float until the 18-meter
rope had reached its limit. The time it took the rope to fully extend
was noted, which allowed the group to establish the
speed, in meters per second, that the
current
was moving. Next another group member held up a compass in the direction
of the rope as it was in the water to obtain a direction, which was read
in degrees. After all of these methods were used to record accurate
test data, the location, time, water depth, and wind speed could be obtained
from instruments in the captain’s cabin. Some of the devices used
were bathymetric maps, and Global Positioning System devices. The
methods were interesting, and the group had a very interesting time collecting
data from both sites at three various depths.
<for
Part 2 of our Trip Report Click Here>
Chincoteaque
Gallery 1
Chincoteaque
Gallery 2
Chincoteaque
Gallery 3
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