Oceanfront Property in Alaska
March 12, 2006
Dr. Herman: Woke up too early, but eating just
before sleeping will do that to me.
This morning, we'll finish recharging the OhmMapper's
batteries, recut some of the ropes that hold the OhmMapper array together,
have the BASC cafeteria's Sunday brunch in a few hours, and then head out
to the sea ice. Which, of course, is just about right outside our windows
since the BASC facility is "oceanfront property." Anyone wanna build a
condo?
By the way, when we got the OhmMapper in the summer of
2004, my students decided calling it "the OhmMapper" was too impersonal,
given how close they were to it and how much they were using it. From now
on, I'm going to call it by the name they christened it:
Ohmy.
If you want to see what Ohmy looks like in action in
sunny San Jose, California, then check it out at http://www.geometrics.com/geoelectrical/geoelectrical.html.
Notice that nice little control console at the front of the operator.
That's the thing that must be kept warm in order to get the data. If that
freezes, then we've got nuthin'. James and I took care of this with a
Wal-Mart trip a few weeks ago. If you take a 12-pack soft cooler, some
thick foam rubber, carseat covers, a Swiss Army Knife, and some needle and
thread, throw in a hard-working student, his girlfriend and his
girlfriend's sewing machine, then you have something that fits under our
polar suits, lets cables and our hands run in and out of the console, and
makes this research trip possible. We'll post "before" and "after"
pictures of James' handiwork.
It's amazing.
Time to go get things ready for today. And, time to
try to find a Mountain Dew.
9 a.m.: 25F below zero, wind chill of 40+ below zero.
Br-r-r-r-r-r-r-r-r.
Good thing we have our snow suits.
We're heading over to the "theater" building on the
BASC grounds. You can look at the BASC layout at http://www.arcticscience.org/.
Last night, before calling it a day, we plugged six of the batteries into
the battery charger, and the battery belt that drives the data-recording
console, to make sure our equipment would be ready to go the next day
(today). Only four of these batteries are used at a time, but I like
backups. This morning, we hit the theater and plug in the rest. We also
talk with members of the U.S. Army's Cold Regions Research and Engineering
Labs (CRREL) team which is up here. They're all civilians, ironically
enough, and there's apparently one Army officer who's at their home base
in Vermont to act as a go-between when they actually deal with Army
projects. Sounded odd to me, but who am I?
Anyway, they agreed with us that we should survey a
300-meter line that they had been using for a week to test out their own
equipment and techniques. This is actually perfect since we get to compare
our results with theirs, and can then evaluate our equipment and theirs on
the same survey line.
We spent the next couple of hours cutting new lengths
of rope to keep the two main parts of the OhmMapper (transmitter and
receiver) very specific distances from each other. We tied loops to make
things accurate down to sub-centimeter scales, which seems too picky until
you realize that every bit of error we eliminate here makes our results
all the more accurate.
Taking no chances.
After lunch, it was time. James and I got him strapped
up into the battery belt harness, with his console-warming contraption on
the front. It took about a half hour, but we did it. He was dying of heat,
but we were able to have him walk outside with everything strapped in. One
problem: The transmitter would not turn on.
Dang.
OK......so I grabbed the transmitter, ran back inside,
took the old Swiss Army knife and worked with the battery contacts. Put
the batteries back in........and it turned on. Took the transmitter back
outside.....James hit the "test" button and everything was perfect! Time
to survey.
We trudged to the survey line with James fully hooked
in. Oh, and we had out bear guide with us. He's the Native Alaskan who
rides the snowmobile, has a big shotgun, and protects us from the
wandering polar bears. Now, odds are we won't even see one. But, if
someone wasn't there, it's just like not having an umbrella making it
rain. Thus, having bear guide = no polar bears.
We shuffled the 5 minutes (maybe about one-tenth mile)
through the snow and over the ice piles, and James stopped right next to
the first survey stake. I took one last look at the transmitter and
receiver. James was ready to hit the "collect data" button....and the
transmitter was off for no reason.
OK, not to panic. Go over and turn it off and back
on.
Nothing.
OK. Maybe bad contact from things contracting in the
cold. Time for the "analytic tap" that I learned about in my undergrad
days in the chemistry lab. This is where you hit it, but not in anger.
Maybe just to get its attention.
Nothing.
Maybe disconnect and reconnect the cables?
Nope.
OK, now time to panic. We trudged back to the theater,
and then noticed that the receiver had turned off on the way. Not
good.
James walked with the whole array into the theater
(big garage-type door), and the receiver promptly turned on. OK so maybe
it's a cold thing. Waited for the transmitter to fire up --
waiting...waiting...nothing. Spent the next hour fiddling with things, and
still had nothing. We finally tried to call the manufacturerbut then
realized it was Sunday when I got their answering machine. Left a
loooooooooooonnnnnnnnnggggg message, a plea, more like it.
Something about, "You guys are in San Jose, and Alaska
Airlines Cargo is at the airport 5 miles from your place. Throw another
transmitter on the plane tomorrow morning, and here's my credit card
number." Scary thing to do, but we want this data.
Gave up, went to eat, and were encouraged by some of
the CRREL members' stories of times when their equipment didn't work for
unknown reasons. The most recent time like this? The last six days for
them. So, we're only out one day? Hah! They've lost weeks at a time
before.
After supper, James and I skulked back to the bunk
house; they call it a "hotel" for some reason, but it's more like a
one-hallway dorm. James says, "Why don't we put in the batteries and watch
it not work" or something like that. But just to check it
out.
Put in the batteries and it worked. OK, we took it and
put it in a snow bank for 30 minutes, and it still stayed on. So now we
figure that it's a metal-not-making-contact problem, and we've got to
figure out where.
We go to the kitchen and ask for some steel wool. The
nice kitchen manager gives us an even better steel scrubbing bundle, which
has lots 'o springy metal for us to work with.
Oh, and she has to interrupt cutting one of her
kitchen worker's hair to do this. And of course, he's still in his white
uniform and apron. This means I am *not* going to get anything for the
next few days in which black hairs can hide! Urp!
For the next hour we fiddle with the thing, trying to
figure out where the problem contact is. It finally seemed that a twisting
hard plastic post is putting too much pressure on the batteries, causing
them to actually lose contact instead of maintaining contact. Twist it all
the way as it should be, and the thing turns off immediately. Twist it
only halfway, but where it will not stay unless held by hand, and the
thing stays on. We, uh, "modify" one of the batteries (yep, Swiss Army
knife again) to relieve some of the pressure, and it turns on and stays
on. And now, it's sitting in my room. I turn it on every half hour to make
sure our fix is working, and so far it is.
We're still going to ask the manufacturer to send up a
transmitter, but we'll try to take the data tomorrow morning with our fix.
If it works, then we'll cancel the request of the manufacturer. Don't know
which will come first, though, the sending of another transmitter (if,
that is, they even have one sitting around) or getting the data with our
fix. But that's tomorrow's question.
Now, I've got to finish putting together a talk on
black hole physics Tuesday night for the town (well, for whoever shows up,
that is). Many thanks to Dr. Brett Taylor who not only saved my bacon
Friday night, but also gave me an electronic packet of pics and stuff from
which I can put together my talk.
But I'm too sleepy to think. I need sleep. Work on
talk early tomorrow morning...
March 2006