The Earth System
Preparation for the
Antarctic Research Facility Lab
The Antarctic Research Facility (ARF) stores the largest collection of marine
sediment cores in the world. What's sediment, what's a core? That's what these
pages are here to help explain. Follow Step One and Step Two. Some common
terms that you may hear in lab will be italicized. After completing
Step Two move on to Step 3: you should be able to answer all of the questions on
the Knowledge Sheet.
Click on each one of the links below. They'll take you to other pages
that will help to explain some of the basic Earth processes at
work that make and deposit sediment, which is what core samples
(a.k.a. cores) are made of. Researchers take the cores and analyze the
sediment to learn about past climate changes (among other things).
What is sediment anyway?
- Sediments, those particles on the ocean floor, are made up of
plankton and small pieces of rock. Small plankton are very
abundant in Antarctic waters.
- When tiny plankton called
a.k.a. "Forams" die, they sink to the bottom, leaving their hard
calcareous (CaCO3) skeletons to
- Diatoms &
Silicoflagellates are about the size of a sand grain. Unlike
have silicious skeletons, skeletons made of silica
are another type of plankton that have a silicious
skeleton. The skeletons
rain down when the organisms die (sometimes after passing through
a fish) and collect as sediment on the ocean floor.
- Your average 'small piece of rock'.
- How and where is sediment deposited, how does it get into a core sample?
The organic particles (Forams, Radiolaria,
Diatoms, etc.) come down directly
out of the water. The other sediments such as: pebbles, sand,
silt, etc., come
from streams (in the Summer) and ice-rafts, icebergs that shed
sediment as they melt. They settle to the
bottom, build up, and solidify to some extent. After several thousand
years of this, core samples can be
extracted by the intrepid scientist. Here's a basic diagram of a general
depositional environment that is similar to that of coastal
Antarctica (although there are no glaciers or
sea ice in this diagram).
Note the location of the continental
shelf and slope.
- Cores look like this:
- Cores often contain fossilized remnants of plankton. Here is one
nannofossils. Other sizes of plankton and plankton with silicious
skeletons get fossilized too.
- This external site will help explain:
What are these cores for and how are they collected?
Now you have some idea of how sediment is formed and how cores are collected.
There some basic principles that scientists apply in order to
deduce what information is hidden in the cores. Review the following sites.
Be very sure you understand the general concepts and terms in italics:
These optional sites may be useful in your preparation, or just interesting.
-Get the lay of the land with
pictures of Antartica
taken near McMurdo Station. Check out the diatoms page under the
"Streams" general heading.
- More pictures of
plankton than you can shake a stick at.
Geologylink geologic glossary has definitions of some basic geological
terms (although not for the plankton).
-The FSU Antarctic Research Facility