by Emma Pearce, PhD student at The University
of Leeds
A beautiful day at Finse, Norway
These three reasons combined meant not only was
I able to apply for funding to support my trip
to Norway, (a BIG thank you to EU Interact) it
also meant, due to the accessibility of the
glacier (in comparison to perhaps… Antarctica),
the logistics of testing a geophysical survey
that might not work were relatively easy.
The
plan was to have two field seasons out in
Norway, the first in 2018, where I would scope
out the best places on the ice cap for my
research where there was known firn coverage,
and do some test surveys, and the second a year
later in 2019, where I would collect my final
dataset.
We packed up all our equipment in the UK and got it
sent by cargo ferry to Norway. Here we picked it up
and then had to attempt to ‘sneak’ the equipment
onto the national Norwegian passenger train.
Luckily
for us, we had a few locals travelling with us up to
Finse, who was able to help us sweet talk the
conductors and fortunately, our five, 70kg boxes
were allowed onto the train, but they did get a few
funny looks.
Once we arrived at Finse,
transportation of the equipment became a bit easier,
we could just pop all the cargo (including PhD
students!) into the sledges, and skidoo ourselves
around. It was April when we visited Hardanger, the
perfect time between the winter’s high winds and
thick snow, and the springs higher temperatures and
snowmelt. The end of April provides a sweet spot,
where there is enough snow that you’re still able to
skidoo around the glacier, but the weather is much
calmer, allowing for the geophysical surveys to be
carried out in the optimum conditions.
Once
we arrived at the station, we had two weeks to
collect all the data we hoped for (two seismic
surveys and some GPR over the ice cap).
Of
course, this all went perfectly to plan, we were
done by the first week, and then had a week to
relax, enjoy the scenery, and get some sledging in….
or.. not.
The equiment
We were heading back to Hardanger in April 2019,
only this year with more equipment (we were going to
drill a borehole on the top of the glacier!), more
data aims, more time, and more people! We had aimed
for the same time of year as it had worked well for
us the year before. We packed up the equipment,
snuck it onto the train in Bergen (well.. this year
we had to pay for ‘bike storage’) and headed to
Finse. It was at this point we started to worry a
little as we looked out the train window, we were
seeing a lot of green and a lot of water, but
fortunately no trolls.
With the warm
weather at the front of our minds, the lake which we
had to cross to get to the glacier was melting more
and more each day, and the warm weather meaning our
route to the ice cap was becoming more rocky and
grassy rather than snow, time was of the essence. To
add to this, there was a fuel shortage on station as
the early arrival of spring had prevented more fuel
being transported to the research station, meaning
every trip in the skidoo needed to be as efficient
as possible. We sat down, and on the big blackboard
in the research station, planned out the bare
minimum that all three teams at the station would
need in order to get the data they were after.
It
seemed that this year, although the sun gods were
VERY much on our side (quite possibly too much), the
skidoo gods were not.
Warm and sunny weather in Norwegian mountains
That afternoon we headed out to the bottom of
the ice cap to drop off equipment. It was at
this point we learnt that the soft slushy snow
meant the amount of weight we could have in the
sledges was greatly reduced. After getting stuck
in a slushy/icey mix, we realised we were going
to have to shuttle equipment and people back and
forth in a logistical dance. Ensuring we didn’t
waste fuel, didn’t break through the lake ice,
and thanks to the appearance of the rocks,
having to take a new route to get to the foot of
the glacier each time we headed out.
Even
though we were at the station for almost 3 weeks
this time, I only needed a minimum of two sunny
(but cold) days to get the data I needed from
the ice cap, and whilst keeping an eye on the
weather every day, waiting for the cold, (yet
sunny) spell to hit, on day 7, they arrived.
With
the sledge packed as light as possible, and some
ferrying of equipment and people done (and only
one very stuck skidoo hiccup later), using the
GPS coordinates from the previous year, we got
back to my field site. At this point, we hit the
ground running, and got to surveying. The plan
for day one on the ice cap was to shoot a
seismic line in the same position as the
previous year, but with the geophones closer
together, and a larger coverage of data. With
the help from the other team members, setting up
the seismic line was quick going, and the
acquisition went smoothly, once again with Adam
at the seismic source, (fortunately less hammer
shots than the year before), and myself on the
laptop.
Drilling the ice cap
At the same time, we had the other team members
sorting out the borehole. It sounded as though
this was all going well, until a loud ‘CRAP’
spilled out across the top of the otherwise
quiet ice cap. It quickly surfaced that the
sound had been Bryn Hubbard, as we looked across
to him with a broken drill in hand and a
borehole stuck 2m deep in the snow. This didn’t
mean the end for the borehole, only that we had
to adjust our aims for the depth as we would be
hand drilling the hole, and that we had to do a
little bit of digging to recover the end of the
borehole. Although time-consuming, digging out
the borehole meant we had a snow pit in the
firn, allowing us to get a close up look at the
density variations in the top 2m of the site,
(we were also able to use the blocks of snow dug
out to make a really great igloo, but that’s
beyond the point!)
With our original
aim of 30m deep scaled back to 10m, we spent the
rest of the day taking shifts at hand drilling
into the ice, we reached a depth of 11m, and
called it a success! With a few bits of glacier
ice collected to take home to have in some gin
and tonics, we were all very happy with what we
had achieved that day, (I can promise you, gin
and tonic tastes even better when accompanied by
ice cubes you drilled yourself). With a bit more
resilience than we previously had, some
successful data acquisition, and the optimism of
another sunny but cold day, we were all excited
for the following day.
Image Description
With our good data day behind us, the next day
was a quicker start, with all the equipment
already on the ice cap we just had to get up
there and shoot the downhole seismic. The
weather wasn’t as nice as we’d anticipated, but
as it had stayed cold, it was safe to get to the
ice cap. Once there, it was just a case of
laying out our geophones around the borehole and
using our downhole seismic source to acquire the
data. Remarkably, for the first time in two
field seasons, everything, went smoothly and to
plan! With spirits high, and a few more bits of
ice collected, we headed off the ice cap in a
few ferried shifts, taking the equipment back to
base, and took a deep sigh of relief. Two years
of planning for data acquisition had all come
together! The rest of the week saw the warm
weather return, meaning the route to the glacier
became near on impossible to traverse, unless
the skidoo had suddenly grown wheels to get over
all the newly appearing boulders. Meaning we
were limited with what we could do, but sledging
on station was always an option.
It’s
clear to see from two fieldwork trips to Norway,
that even with the best intentions of planning,
things don’t often go the way you expect! None
the less, I had two fantastic field seasons,
with great company, amazing food, and a few
awesome datasets collected!
I want to
say the biggest thank you to everyone who has
helped over my two field seasons, most notably
Adam Booth for being the power behind the
seismic sledgehammer. A big thank you also to
Siobhan and James Killingbeck, Hannah Watts,
Benedict Reinardy for their help with acquiring
the seismic line. Bryn Hubbard and Katie Miles,
for their help with drilling the borehole. And
Kjell Magner for his logistical help on the
icecap, meaning we didn’t end up in a crevasse.
And of course, the biggest thank you to Marits,
for all the amazing food she cooked to keep us
sustained each day! And finally, thank you to
the INTERACT team for funding this
fieldwork.
To come
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