1 August, 1997
Nevins Journal 08/01/97
We spent today trying to get the online contacts with glacier working and
then setting up some maps that show the polar region and our study area in
Alaska. There is not much to report concerning that process but when you
read this it means that I got through. We are still working on contact
with my e mail server.
Part of the afternoon I went out with a G.P.S. system and tried to run a
course with the system. It is not quite as easy as it is billed. I think
I figured out what has been going wrong so far though and I'll try the
correction tomorrow. If I had to rely on it now though it would be a good
way to get lost. Think about what it would be like to navigate with a
compass and clock for your main tools.
Question: How much would you miss your destination by in a 100 km trip if
you made a 1 degree error in your compass direction ?
Contrary to what many people think, a magnetic compass does not point
north. It points to where the North magnetic pole is located. This is
the same as true north only along the agonic line and in all other places
the compass points East or West of true North. The agonic line goes
through Wisconsin near my home but I still have a 1.5 degree east error.
The angle East or West of true North is called the magnetic declination.
This angle is given on some U.S.G.S. Maps so that users can navigate from
the map. Here in Albany the declination is about 13 degrees west and when
we get to Alaska the declination will be near 25 degrees East. Better
quality compasses have an adjustment on the face so that you can set a
correction into the compass dial. On the Silva Ranger compass that we
used today, that adjustment is a small screw that turns the dial face in
an East or West angle separate from the scale on the outer edge of the
compass.
Tomorrow we plan to visit another of Mike's sites about 3 hours from here.
More tomorrow.
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.
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