by Guest Blogger
August 15, 2005
“Please work”, said Jason Box (Ohio State Geography/Byrd Polar Research
Center glaciologist) as if in prayer, before we even land. This morning
he had retrieved the first of his automatic monitoring cameras – set up
last May. It had taken exactly one photo (the day after he set it up),
and then stopped working. Definitely a setback, although not entirely
surprising given the harsh conditions, precarious nature of electronics
and this relatively novel application of automatic monitoring.
Now we are landing at a second site. This one on the ice sheet itself.
As soon as Hughie (heli pilot) gives us the OK, we’re out of the
helicopter and getting the camera down. When Jason installed it, the
white battery box was at ground level, but as usual the winter snow has
all melted by now – leaving the batteries almost out of reach. Carefully
we lower the mounting pole and open the airtight camera enclosure.
Jason’s too eager to check the camera to explain his setup just now, but
we go over it later.
How it works
The camera is a regular consumer brand digital still camera connected to
something called an “intervalometer” – a device that operates at
intervals. The intervalometer takes a picture every few hours throughout
the day. The power comes from two sealed gel cell batteries, like car
batteries but smaller, recharged by a 20 watt solar panel, which Jason
calculates supplies about twice as much power as the system needs. The
enclosure is the same type used for security cameras, and is packed with
silicon desiccant to absorb the moisture inside and keep the glass from
Jason tested his equipment in an Ohio University cold room with
temperature sensors inside the camera. Even at -4 Fahrenheit (-20C) the
camera kept itself warm enough to stay just above freezing. Although
Jason first used a digital camera to do time lapse monitoring (of snow
drifts) in 1996, and Station Zackenberg has had a year-round camera on a
mountain since about the same time, the ones we took down today are the
first long term monitoring cameras on the ice cap that Jason knows of.
[View snow drift animation here: http://polarmet.mps.ohio-state.edu/jbox/drift]
When Jason set the camera up on location, he and his college surveyed
the area and set out marker flags at known GPS coordinates to give him
some frame of reference when looking at the photos. The surrounding
landscape is changed over time by snow, rain and wind (although no
matter what time of year it is, the scenery at the camera site can be
described as “basically white”).
The all important data
When we get it down, the enclosure is intact, and the camera in good
shape. Jason gingerly pulls it out, and turns it on. “There are 516
pictures on this camera,” he tells me grinning. Looking at the images
back on the ship, we realize that he has succeeded in documenting a melt
lake forming – and draining, and forming, and draining, and so on. This
is slightly unexpected, and possibly interesting. Other melt lakes have
been observed to fill slowly, and then drain suddenly.
At the third site of the day, the camera proves more difficult to get
down. We end up using a hacksaw to cut through its mounting pole. This
camera has also worked. It monitored a ridge in the ice sheet. If the
ridge changed position as summer went on, then it was probably related
to climate events, if it stayed in one place it was probably structural
to the ice sheet. Just eyeballing the images, it looks like it didn’t move.
Later, the two working cameras will both be redeployed to monitor the
front of Jakobshavn glacier. Jakobshavn is a well-studied glacier that
has more than doubled in speed over the last ten years. Intensive
monitoring, using these cameras, will provide insight into how fast it
is moving at its bottom end, and how much its speed varies seasonally.
This is an outlet glacier – meaning it transports ice from the ice sheet
down into the ocean. Outlet glaciers are thought to be vital to the fate
of the Greenland ice sheet, and the fact that major ones surveyed on
this trip are speeding up is alarming.
The data collected, although not Earth shaking, will add to the body of
knowledge about what is happening to the Greenland ice sheet. Also
important, is that this method of collecting data can be applied in
other research areas as well ” such as monitoring the volume of ice
coming off glaciers in the form of icebergs.
This is often how science works, not with Jurassic Park like suddenness,
but with incremental steps forward. One experiment leading to the next,
and a continuing refinement of techniques. In fact, it took over a
decade, and hundreds-of-thousands of man-hours, before the authoritative
scientific body on the subject concluded that our planet is heating up
at least in part (probably mostly) because of our greenhouse gas
emissions (2001 Intergovernmental Panel on
Climate Change Third Assessment).
It’s folly to ignore so much painstakingly accumulated scientific
evidence – yet that is what many, including the Bush administration, are
trying to do. Despite their resistance, we need to start an energy
revolution – to go from a fossil fuel dominated energy strategy to one
that takes advantage of renewable energy technologies. If you are in the