Before I head home this week, I have one more adventure to tackle here in Iceland: my glacial geology field work trip! For five days, my forty classmates and I are traveling with our professor and some graduate students around South and West Iceland to observe glaciers and the landforms they leave behind. Here is a recap of our trip, probably the most epic field trip I have been on.
Saturday (May 12th)
Saturday was our first day of field work and consisted of three primary stops: the Ancient Forest, Gígjökull, and Steimsholtjökull. The Ancient Forest is a patch of dried tree stumps which were killed in a flood. This flood was caused by a sub-glacial eruption from Katla volcano which is under the Mýrasjökull glacier. By dating the trees, scientists concluded that all of the trees died at the same time around 823 CE. This site was only revealed 15 years ago by another flood, which is why it’s a hotspot for glacial-flood related research now. Both Gígjökull and Steimsholtjökull are glaciers further inland from the ancient forest. These glacial tongues extend down from Eyjafjallajökull, the famous subglacier volcano which erupted in 2010. Both of these glaciers have released giant floods as a result of eruptions and other events, similar to the one which killed the ancient forest. Being able to predict flood events as a result of the interactions between glaciers and volcanoes is very important in Iceland because these massive flood destroy property and infrastructure, and have the potential to change the physical landscape and kill people.
Sunday (May 13th)
On Tuesday, we spent the entire day at Solheimajökull, another glacial tongue extending from Mýrasjökull. In the morning, we walked around the outwash plain of the glacier (the flat flood zone in front of the glacier) and observed different landforms (in layman’s terms, different types of gravel piles) from different time periods. For example, further away from the glacier we see features which date back to the Neo-Glacial era (2,000-3,000 years ago), as well as the Little Ice Age (600-800 years ago). Most notably, we see the moraines (linear mounds) which mark the end of the glacier at different points in time. Starting from the moraine from 1995, we can follow the retreat of the glacier as a result of climate change until now.
For the latter half of the day, we hiked on the actual glacier and practiced drilling into the ice using a steam drill. Basically, to operate a steam drill, you have a boiler filled with water which is heated using camping fuel. When the water boils, it releases steam through a hose which is connected to a hollow spike. The steam warms and escapes the spike through a small hole at the point. By facing the spike vertically downwards, the stream of steam will heat the ice below and slowly bore a hole down. These types of drills can be used to take measurements below the ice.
Monday (May 14th)
On Monday we spent our entire day at Sveinafellsjökull and Skeiđarárjökull, outlet glaciers of Vatnajökull, the largest glacier in Europe. We started the day by hiking around the ice margin and proglacial lake of Sveinafellsjökull. One of the PhD students who was accompanying out trip talked a bit about her research with ice cores. In general, ice cores can be used to measure changes in the temperature. This is done by measuring the concentrations of different water isotopes in the annual layers of ice. Essentially, if there is a warmer year, there will less “light” water isotopes because they evaporate out more quickly. In her project, the PhD student was looking at how volcanic eruptions in the area change the regional temperature and how that effects the concentration of different water isotopes.
The second part of the day was spent walking around the outwash plain of Skeiđarárjökull. This particular glacier in the largest outlet glacier from Vatnajökull. It is also a surging glacier, which means that it does not have the same annual growth and retreat as normal glaciers. Instead, it experiences periods of very fast flow which cause it to expand quickly (maybe every few years). After it surges, it leave behind lots of “dead ice” – ice disconnected from the main glacier.
Tuesday (May 15th)
On Tuesday, we continued our trip in the morning by heading east to Veiđarsandur. This sandy area is another outwash plain filled with sediments from the volcano, Katla. Eurptions from Katla melt the overlying glacier, Mýrasjökull, and cause it to flood and transport volcanic ash to the area down below. In 1918, there was a giant flood caused by a Katla eruption which carried enough sediment downstream to extend the surrounding coastline out 4 kilometers into the sea. This eruption actually connected an isolated island to the Icelandic mainland. Some of the Icelandic coastline is dependent on regular floods of glacier melt and volcanic ash to maintain the land. Currently, the small town of Vik is facing problems with coastal erosion since Katla has not erupted in 100 years to provide to sediments to the coast.
Later, we continued our journey to an older glacial landscape, named Völlur, closer to Reykjavik. Here we saw geological remnants from the Last Glacial Maximum 14,000 years ago. At this point, our group of fifty early-mid 20-somethings began to mentally devolve to kindergartners after spending 4 long days together. So here, there were lots of people tumbling boulders down hills and tumbling around in the moss.
Wednesday (May 16th)
Wednesday was our final day on the trip, and we focused on glaciomarine environments (where glaciers meet the ocean). During the Last Glacial Maximum, Iceland was completely covered by glaciers which extended into the Atlantic. The glaciers were so heavy that they caused the island to sink nearly 60 meters into the ocean. Once the retreated, the island rose again. This phenomena is known as isostatic rebound. Because of this, there are specimens of marine interactions available for us to see on land.
Most of our day was spent at some sea cliffs about an hour north of Reykjavik studying the structural geology of the cliff. Essentially, we were tracing different layers of sediment along the shoreline to see which layers were deformed during which glacial time period. A local farm dog decided to join our walk along the beach and probably had the best time of all of us receiving pats from every student.
This blog post is the final one for my exchange here in Iceland. It has been a really great semester, and this field trip really rounded it out well. Of course, it is always bittersweet to say goodbye to my friends, but I hope to see them again in the future. It’s been a semester full of bizarre and interesting experiences and has been truly worthwhile.
-Emily
P.S. Here are some pictures of me snorkeling last week in Silfra, a crevasse in Þingvallavatn – my bucket list activity for my last free days in Iceland.
