MARGINS: Learning from Sediments

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MARGINSLearning from Sediments
Follow the 2006 Research Mission to New Zealand.
Use the activity, Whats the
story? Author Venetia Butler 2008
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• Whos on this mission?
• Scientists
• -- work in teams
• -- keeping accurate records
• -- sharing the data
• -- answer oceans questions
• Educators _
• --learn the research process for themselves
• --share with students
• authentic learning

Venetia Butler, Savannah, GA Kelly Sears, Chapel
Hill, NC
Team Leader, Dr. Clark Alexander, Skidaway
Institute of Oceanography, studies the
depositional basin of the Waipaoa River, New
Zealand
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The Study Site

• New Zealand
• Hawkes Bay
• Poverty Bay

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Continental margins are offshore areas comprising
the continental shelf and slope, consisting of
sediment layers from land and sea

• Research goals of the MARGINS program
• Understand how those areas function today
• Investigate rate of deposition
• Investigate the source of the sediment layers
• Discover any human impact on layers.

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MARGINS Source-to-Sink Research Questions

• What processes control the rate of sediment
  deposition?
• How does transport through from river to
  continental margins effect the amount, grain
  size, and delivery rate to sediment sinks?
• How do the layers from sediment deposition tell a
  geologic story in its by the stratigraphic record?

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Cruise planning began in GeorgiaContinues in
Napier, New Zealand
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• New Zealand 70 m research vessel Tangaroa arrives
  in the NZ port, Napier

• Dr. Alexander prepares the research team,
  discusses tasks prior to leaving port.

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Orientation

• Scientists discuss the
• research plan. Ships crew introduces safety
  procedures to all scientists and educators

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Orientation Video
Dr. Clark Alexander in New Zealand prepares for
the Cruise.
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The research cruise begins . . .
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What to expect as a Educator at Sea. Small
functional cabins, cozy galley. Good food!
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Ships A-frame at the stern handles heavy
equipment for coring.
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Multicorer- ready for a midnight station.
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Sediment Cores from the multicorer are d placed
in the lab. A technician samples the top layer
of the core.
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Multicore Core Sample preparation
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An occasional surprise!
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Sediment Cores Contain Fossils Single celled
Foraminifera

• Forams are index fossils for
• Geologic Dating
• Climate
• Depth

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Every 2 cm of each sediment core is bagged and
labeled.
Measured back in the U.S. for radionuclides Lead
-210 to calculate the rate of sediment
accumulation Thorium-234 to measure biological
seabed mixing rates Beryllium-7 to document the
presence of sediment from the river within the
past year.
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Core samples undergo X ray analysis.
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More X-rays
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Gamma Detectors
Isotopes are counted with gamma detectors.
Isotopes are used to determine age and
accumulation rate of sediments
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Sampling means a very long night!
Scientists reflect, reevaluate revise the
research process. Is it working?
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Scientists and Educators join in all Tasks
Venetia Butler works in the deck based lab, the
box!
Clark Alexander checks seismic charts
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A storm moves in and the water gets rough adding
to the difficulty of tasks and comfort of the
crew.
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• After the storm, the piston corer is deployed.
  It collects longer sediment samples than the
  multicorer.

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Observe the differences in the core of the piston
core and multicorer. Notice the length and weight
of the piston core. How can these long cores be
stored? What will have to be done in order to
ship these very long cores to the home research
labs? Is it important to pay attention to the
top and bottom of the core?
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Preparing Documenting Piston Cores
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Core Analysis reveal a tephra!Whats the story?
A tephra is a volcanic ash layer. It can be used
to determine the age of the sediment at this
site. The chemical composition of the ash can be
traced back to a specific eruption and volcano.
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Analysis for magnetic susceptibility
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Piston Coring Video
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At port in New Zealand, cores and equipment are
shipped to US research laboratories.
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New Zealand National Institute of Water
Atmospheric Lab (Video)
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Core analyses continue at Skidaway Institute of
Oceanography, Savannah, GA
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• Claudia Venherm, Research Technician, prepares
  the core Samples
• Sediments samples are dried in the oven and moved
  to dissector.

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Weighing in ..
A mortar and pestle are used to crush the samples
before weighing. Samples are weighed before and
after going in to the oven to determine their
porosity.
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Recording accurate data is essential
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MARGINS The Research Mission 2006-2008
Cruises
Stayed Tuned and Keep Engaged with Ocean Research
COSEE SouthEast serving NC, SC and GA
Comments/Questions Contact Venetia
Butler venetiabutler_at_bellsouth.net