By Riley Hollenberg
On the morning of May 21st, 16 team members departed from Reykjavík for Mýrdalsjökull. We included folks from Háskóli Íslands, the Icelandic Glaciological Society and the Icelandic Met Office. We were also acompanied by a youth contest winner from last year’s UN Year of Glaciers, Þórey María Kolbeinsdóttir, who joined us to collect measurements and participate in field work on a glacier. She brought along her sister to share in the experience! You can read more about the International Year of Glaciers Preservation here https://hi.is/frettir/althjodaar_jokla_hafid_vidburdir_i_hi_a_arinu (in Icelandic). You can also browse the winning entries here: https://un.is/samkeppni-ungs-folks/ (in Icelandic).
The goal of the day was to visit three measurement sites located on the southern portion of the Mýrdalsjökull ice cap. At each site, we planned to drill through this year’s accumulated snow and recover segments of the snow core to measure and document any noticeable features. How would we know when we have drilled deep enough? In fact, we were on the lookout for a distinctive dust layer that represents the surface of the exposed glacier surface during the last summer. This process proceeded as follows:
- The “drill team” set up the drill and battery and commenced drilling ~1m at a time.
- When the drill was filled, the snow core was gently emptied onto a platform for measurements.
- The “measurement team” initially measured the full length of the (often broken) core, along with its diameter, and recorded it in a field notebook. The internal temperature of the core was also measured and recorded in ~20 cm increments. Finally, the lengths of individual segments were measured, weighed on a scale, and any features such as ice lenses were noted in the field notebook.
- Additional length was added to the drill to be able to recover deeper and deeper cores, and the measurements were repeated.
- Finally, when we identified the dust layer (representing the glacier surface from last summer), the depth of the dust layer was calculated!
At the first site, just over 12 m of core was recovered with the dust layer sitting at a depth of ~11.5 m. Ice lenses were identified along the ice core, but some significant 8 cm lenses were found at depths of 11.4 m just above the dust layer.
The second site recorded a depth of 8.86 m to the dust layer, with a full core length of 9.59 m.
At the third site, at a higher elevation along the rim of the Katla caldera, both groups came together for the last drill site. Here, the depth to a dust layer was ~ 6.20 m, however it is uncertain if this represented the last summer’s surface or if drilling should have continued. To finish off the day, we shared some celebratory cake for our hard work and piled the equipment back into the vehicles and pretended to have good views of the surrounding landscape on the descent. In reality, we had just spent the last few hours in a thick fog that really made it hard to see where the sky stops and the glacier starts on the horizon, but that’s part of the experience!
