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Re: [Phys-l] polar grid navigation

Thanks for the links! I particularly like the LuAnn Dahlman's blog with maps showing the difference between "Grid North" and "True North". I also note that in the accompanying paragraphs, there are statements like this:

"When I focus in on our location on these maps, my brain has to do a mental transformation so that I don't interpret down as south."

Clearly _she_ is not confusing true north with grid north, or grid south with true south.

If the direction from the South Pole to Lake Vostok had been given in the media as "grid east-southeast" it would have provided a clear indication that some local coordinate system was being used, there would have been no confusion between that direction and "east-southeast".

Where did the confusion enter? When I speak about my own field with those without the background in it, I do try to explain terms I use, but sometimes Fachsprache terms, abbreviations, etc., creep in. So I can picture an Antarctic scientist saying "east-southeast", forgetting that the news reporter would not understand the "obvious" meaning "grid east-southeast". A mistake of omission. But more likely the scientist interviewed would give a perhaps too extensive explanation, the reporter's eyes would glaze over, and he would simply use the map as if it were oriented "like all maps", and not seeing the glaring paradox of heading southeast from the South Pole would pass on his own misunderstanding to the public!

A mistake was made, whether a mistake of omission or a mistake of miscomprehension.

In answer to the question posed -- "What more do you want?" -- I have a simple answer: now that it is apparent that the issue is semantics ("south" used in two different ways in the phrase "east southeast of the south pole", once as a "grid direction", once as a "true direction", I want to go back to my regularly scheduled life.

Hey! -- I can do that without waiting for anyone's permission. Hurrah! I just made my day. :-)

Ken Caviness
Physics@SAU

-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Michael Edmiston
Sent: Thursday, 16 February 2012 3:10 AM
To: 'Forum for Physics Educators'
Subject: Re: [Phys-l] polar grid navigation

Well... you might try finding something about it from people who have actually been in Antarctica and have used grid-north maps.

Below are some things I found.

* * * From
http://passporttoknowledge.com/lfa/QA/computers/Directions,Time,ZIP * * *

QUESTION: How do you give directions at the South Pole? Wouldn't everything point north?

ANSWER from Craig Mundell
You are correct. Theoretically, every direction from the South Pole is north. To get around this problem, people in the U.S. look at the continent as a grid map with McMurdo Sound to the bottom of the page and the Antarctic Peninsula to the upper left of the page. They then use directions like it was any other map, i.e., the top of the page is north, bottom south, etc. In fact, with the grid map system the navy pilots use here, they actually fly north from McMurdo to get to the South Pole.

ANSWER from Bob Loewenstein on February 8, 1995 Geographically speaking, every direction at the south pole is North (except up and down). But we do have to tell people things, like the wind direction is so and so. To do this, we adopt what is called a 'grid north' system, where north is in the direction of zero longitude (toward Greenwich, England). East is 90 degrees, South 180, and West 270.

* * * Who are Craig Mundell and Bob Loewenstein ? * * *

By doing some Googling it appears that Craig Mundell wrote this while he was living at McMurdo Station and working in aviation support for getting people from McMurdo to the South Pole Station and other research locations in Antarctica.

Also by Googling we find that Bob Loewenstein is a Senior Research Associate at Yerkes Observatory

From New York Times, January 10, 1995 we read... Dr. Robert
Loewenstein, an
astronomer from the Yerkes Observatory of the University of Chicago, who is developing a system that will be used to operate, from a long distance, a whole family of advanced telescopes blooming this year at the South Pole.


* * * Go to this page
http://www.andrill.org/iceberg/blogs/luann/all.php#id2258259 * * *

Scroll down until you get to the grid north map. Read the paragraphs that go with the map. Also notice that the map indeed puts north at the top, south at the bottom, east on the right, and west on the left.

The map was made by Jessica Walker. It appears she has a PhD in GIS, and at the time she made the map she was working for Raytheon Polar Support Company in McMurdo Sound.

The webpage showing the map is done by LuAnn Dahlman. Here is a blurb on her...

LuAnn Dahlman
NOAA Climate Program Office
LuAnn Dahlman is a writer and editor for the Communications and Education group at NOAA's Climate Program Office. She earned a Bachelor's Degree in Geology at Arizona State University, and served as a practicing educator,
K-12 curriculum developer, and workshop leader for inservice educators for more than 20 years. She has served as co-PI and Project Director on several NSF projects that encourage the use of technology and Earth science data for teaching and learning. During the 2006-2007 field season, Ms. Dahlman worked as a member of the ANDRILL project-ANtarctic geology DRILLing-recovering sedimentary rock records from beneath McMurdo Ice Shelf in Antarctica.

* * *

So there you have four people who have spent some time in Antarctica telling you that people "down there" use a grid-north map, and when looking at the map they consider the top as north, the bottom as south, the right as east, and the left as west. The person who drew the map is a GIS specialist, one of the persons who described the situation worked with Navy pilots in Antarctica, another is a PhD astronomer, and the fourth is a geologist working as a writer for NOAA.

What more do you want?





-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of brian whatcott
Sent: Thursday, February 16, 2012 12:28 AM
To: phys-l@carnot.physics.buffalo.edu
Subject: Re: [Phys-l] polar grid navigation

On 2/15/2012 4:27 PM, Bernard Cleyet wrote:
On 2012, Feb 15, , at 07:11, chuck britton wrote:

At 9:58 AM -0500 2/15/12, Edmiston, Mike wrote:
So... after all the messages posted on this list-serv ridiculing the
news reports... it turns out the news reports were correct. If you
use the pseudo grid for Antarctica that navigators and scientists in
Antarctica are known to use (where grid north aligns with the prime
meridian), then Lake Vostok is indeed southeast of the south pole.
Actually I would call it "east southeast".
http://geology.com/world/antarctica-map.jpg

http://en.wikipedia.org/wiki/Boxing_the_compass

Yes, number 11.
Oh my - given a whiff of polar grid navigation, which allows a direction indicator once set to hold a chosen course, I see we are leaping to (totally
unwarranted) conclusions about the Vostok Lake lying to the south west of the pole.
Grid navigation specifies courses 0 to 359 degrees grid..... not often thought of as sou,sou-east, by east and all that good stuff....
And a polar projection does not constitute a polar grid for navigation in itself.....

But why am I burning electrons so fruitlessly? :-)

Brian W


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