Transcript Student ppt presentation

Life in Extreme Environments:
A Study of the Prevalence of life in the
Depths of an Underwater Rift Zone
Mid-Ocean Ridge
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Center of tectonic activity located
towards the middle of an ocean.
Source of seafloor spreading. New
land is created at all Mid-Ocean ridges
which then spreads outwards towards
deep ocean trenches.
Contains a rift zone which appears as
valleys running along its spine.
The rift zone is booming with biological
activity, as a result of the areas
hydrothermal vents.
Depicted in the diagram to the right is
the East Pacific Rise, a mid-ocean
ridge located in the Pacific ocean,
which will be the basis of our study.
Hydrothermal Vents in the Rift Zone
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Form where there is underwater
volcanic activity – primarily in rift
zones.
Caused by the infiltration of seawater
into the crust where it is heated and
shot back into the ocean via the
chimney of the vent.
In the crust, the temperature of the
water is raised up to 400°C.
Additionally, the water is
deoxygenated, made acidic, gains
hydrogen sulfide, and picks up a
variety of dissolved metals including
iron, copper, and zinc.
The heat at these vents make them
ideal spots for biological activity.
Vent Life
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Typical vent lifeforms include
tubeworms, octopi, clams, shrimp
mussels, zoarcid fish, crabs, and
various microbes.
As sunlight does not reach the floor of
the rift zone, the main sources of
energy for the system are the vents.
The sheer amount of chemicals
emitting from these vents allow a
series of microbial chemosynthetic
reactions to take place which provides
the basis of all of the energy in the food
web of the system.
Topographic Profiles of the East Pacific
Rise
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Shown below is the partial profile of the
topography of the East Pacific Rise.
Topographic Profiles of the East Pacific
Rise (continued)
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Shown below is a cross section of the East
Pacific Rise's topography. The vents and the
majority of life forms are located in the trough in
the middle of the profile.
Hypothesis 1
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Life forms are only found inside the axial trough
of the East Pacific Rise.
We will test this hypothesis by analyzing a
series of maps using the program GeoMapApp.
Life in the East Pacific Rise
• Blue dots represent hydrothermal vents with no
presence of life.
• White dots indicate the presence of life.
• Based on the previous image, it is clear that life
exists both inside and outside the trough.
Hypothesis 2
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Water temperature plays in important role in
determining where certain species are found on
the east pacific rise.
We will test this hypothesis by using the
program GeoMapApp which will allow us to
directly observe the relationship between
temperature and number of life forms in specific
regions.
Data Table
Hypothesis 3
Previously, we have determined that life exists
both inside and outside of troughs.
We have also established that water temperature
does indeed affect the prevalence of life.
As a new hypothesis we would like to establish a
relationship between location, temperature, and
prevalence of life.
Based on the graph, it is clear that water
temperatures inside the trough is more suited to
sustaining life.
Another factor that influences temperature is
whether or not hydrothermal vents are located
within proximity, causing temperatures to spike.
Finally, because temperatures inside the trough
are more suitable for sustaining life, there is a
greater prevalence of life inside of the trough.
Interpretation of Data
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In areas of both relatively low temperature, and
relatively high temperature, there are not very
many life forms, nor is there significant
biodiversity.
There is both biodiversity and many life forms in
areas of temperatures ranging from 17°C –
22°C.
Conclusion
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Water temperature does in fact play a large part
in detirmining how many life forms live in a
specific region of the East Pacific Rise's rift
zone.
The ideal temperature for life forms seems to be
anywhere from 17°C – 22°C. Areas in which
the temperature is higher or lower house fewer
organisms.
Not only is the amount of organisms greater in
this range of temperatures, but the biodiversity
is greater as well.
Sources
http://www.divediscover.whoi.edu/vents/index.html
http://www.divediscover.whoi.edu/ridge/index.html
http://www.ncbi.nlm.nih.gov/books/NBK26866/