16 October, 1998
Welcome to the world of paleomagnetic geology!
This journal entry is a summary of my June, 1998 trip to the University of
California at Davis. This trip to UC Davis was VERY worthwhile for many
reasons. First, it provided the opportunity for me to visit with my PI
(Principal Investigator), Dr. Ken Verosub, and get to know him better. It
also gave me the chance to become familiar with the research we will be
working on in Antarctica, and to use some of the technology that will be
employed in the field. We had the chance to talk about the various aspects of
the TEA program, and I felt that a lot of questions were answered, (for both
of us). Finally, I was able to share with Ken WHY I wanted to be a member of
the TEA program, and how I feel I can use this experience with children,
teachers, and other adults.
In the past three weeks (late September/early October) I have given about 16
presentations at schools in my area. I have met with elementary, middle, and
high school students and teachers, and a science methods class at Northern
Illinois University. All of my preparation has maximized my ability to teach
about a VERY exciting topic: ANTARCTICA !! I feel more confident about basic
knowledge of the Cape Roberts Project, logistics of my upcoming trip (I leave
tomorrow !!) and how I fit in as an active member of the paleomagnetic
research team. The work is just beginning !!
Back to June...I started my first day of my visit to UC Davis with a brief
tour of the campus, and ended up at the geology building. Ken didn't waste
any time getting me into the lab and working with equipment that would
familiarize me with paleomagnetism. Most of the equipment that we used to
measure samples was in a magnetically shielded room. This room is designed to
produce a very low magnetic field, and to shield out the Earth's magnetic
field. We sat on plastic chairs and used desks/tables made of plastic or
wood. The machinery is extremely sensitive and expensive.
Using a cryogenic magnetometer, I measured the magnetization of small samples
of sediment. The cryomag (as it is called for short), uses super conducting
electronics to measure the magnetization of the sample. This process involves
lots of little steps, and it was good to have the chance to run through a
series of tests and repeat these steps many times. All of the information and
steps were recorded on a special computer program. In the field we will use a
portable magnetometer. I think it was great to be able to use this larger one
to start off.
Next I moved to an AF (alternating field) demagnetizer. This machine removes
the secondary component of magnetization of the samples and allows you to see
the primary component of magnetization more clearly. Again, lots of smaller
steps-- turning the sample three different directions to perform various
functions, and then using the cryomag to go back and measure the magnetization
of the sample. We repeated this process by demagnetizing the sample at
various levels.
I learned a lot about how the drill core samples are transported...in
something called a mu-metal shield. This is a box (or container of some sort)
that shields the magnetic field of the Earth. I also saw the drill press that
is used to drill the core samples. The core that is brought up by the drill
in the field is about 3 inches in diameter. They slice this in half and lay
the flat side down, curved side up. The drill press has a diamond blade that
cuts through the rock/sediment core, resulting in a small cylindrical drill
core sample that is 1 inch long and 1 inch in diameter (about the diameter of
a quarter).
Later I helped Ken unpack some of the equipment that was used in Antarctica
during the 1997 field season (last October through December for this project).
It was shipped back to UC Davis and some of it was just being unpacked for the
first time. This was interesting because this IS the equipment we will be
using when I get to the Crary Lab in McMurdo. A MINISPIN (which is a high
sensitivity, portable, slow speed spinner fluxgate [type of electronics] ) and
a small Molspin shielded demagnetizer were the two most important machines I
became familiar with. After assembling the demagnetizer, Ken showed me how
both machines worked.
The next day I used both machines to test 5 drill core samples from last
year's Cape Roberts Project. First I tested each sample with the mini-
magnetometer to see what their magnetization level was. I recorded these by
hand, because we didn't have the computer software that accompanied this
machine. Next step...Ken added some magnetization to each sample. He used a
piece of equipment called an automated long-core cryogenic magnetometer.
There are only about 10 of these in the world, and UC Davis was one of the
first places to get one. It is a VERY expensive machine. I went back to
measure each sample using the mini-magnetometer to look for changes in the
level of magnetization.
Finally, I went to the demagnetizer and went through quite a few levels of
demagnetization and measurements using both machines. I was constantly up and
down, moving back and forth between the two. I collected tons of data and
entered my results into a spreadsheet program on the computer. Later Ken came
in and rearranged the data so we could print it out in several different types
of graphs. When using these graphs it was easier to interpret the information
I had collected.
Ken gave me some drill core samples to take back home and use for my
presentations. I have samples of each of the three different types of
rock...igneous, sedimentary, and metamorphic. These have come in handy as
I've tried to explain what I'll be doing in Antarctica. Ken also gave me some
small clear boxes filled with samples of sediments.
The last two machines I learned about were a magnetic susceptibility meter and
a thermal demagnetizer. The first one measures how susceptible the rock is to
magnetization by an external magnetic field. The second demagnetizes a rock
sample by using heating and cooling chambers.
The scientific study of the cores collected in the Cape Roberts Project will
include not only magnetostratigraphy (the study of magnetic properties), but
biostratigraphy (the study of fossils used to date sediments), petrography
(the study of rock types), mineralogy (the study of minerals), and
sedimentology (the study of the conditions under which the sediments were
deposited). I KNOW I have a lot to learn, but that means a lot to share as I
continue on this adventure.
Stay tuned for more information on the Cape Roberts Project and my trip to the
big white continent !!
A photographer from my local newspaper came to take some pictures, and since I was already in the gear (by the way, it was about 95 degrees that day!) I had my son, Matt, take a few photos of me.
When I got back from UC Davis, a set of ECW (Extreme Cold Weather) gear had arrived at my house. This was the gear I used in all of my presentations. I'll be getting my own set (to borrow) when I arrive in New Zealand next week.
Here's a close-up shot of the drill.
The University of California at Davis campus...June 1998
This machine is called a cryogenic magnetometer...cryomag for short. I practiced measuring the magnetization of small samples of sediment. All of the information was recorded on a special computer program. This is the MINISPIN...a more portable magnetomer .
This machine is called a cryogenic magnetometer...cryomag for short. I practiced measuring the magnetization of small samples of sediment. All of the information was recorded on a special computer program. This gives you a good idea of the size of our sam ples.
This machine is called a cryogenic magnetometer...cryomag for short. I practiced measuring the magnetization of small samples of sediment. All of the information was recorded on a special computer program.
Checking out the Molspin on my own and practicing procedures we will use in the lab. Dr. Ken Verosub...working on the Molspin shielded demagnetizer that we will use in Crary Lab in McMurdo.
Checking out the Molspin on my own and practicing procedures we will use in the lab.
Dr. Ken Verosub holding a portable drill used to take core samples in the field.
Contact the TEA in the field at
.
If you cannot connect through your browser, copy the
TEA's e-mail address in the "To:" line of
your favorite e-mail package.
|