Project Report

We surveyed the landslide mechanism around Siorapaluk settlement from July 27 to August 3, 2023. The landslides are generally characterized by shallow collapse depth of about 2 to 3 meters, but they flowed down to the coastline several hundred meters away as debris flow（Fig. 1）. These landslides were triggered by heavy rains in the summers of 2016 and 2017. However, the heavy rain events are not the only reason why a number of huge landslides occurred. We think that geological structures and permafrost also play an important role in the occurrence of the long-distance landslides.

In this year’s survey, we applied electrical exploration to understand the internal structure of the landslide (Fig. 2). The electrical exploration measures the distribution of underground resistivity by sending current from a number of electrodes installed on the ground. The cross-sectional diagram of the electrical exploration showed a low resistivity (moist) zone near the collapse source.

We also attempted to detect springs on the landslide slopes using thermography. The slopes had been dry because of little rain, resulting in no springs detected at first. However, at the end of the survey period, when it rained for the first time in a while, thermography detected spring water coming from the landslide sources (Fig. 3).

The results of electrical exploration and thermography indicated that subsurface structures tend to collect water near the landslide sources. Such structures are often hidden by unstable debris covers in cold regions with low landslide frequency. If the amount of rainfall increases in the future due to climate change, the risk of debris-flow occurrence will increase. It is important to tell residents the risks of slope disasters.

What happens if you travel to one of the most northern settlements in the world and mix the following ingredients? Innuits, kids, Japanese sushi, cookies, powerful loudspeakers, slides, and lots of coffee (Fig. 1)? Of course, a workshop! Such kind of public events have been held by the members of our expedition almost annually in a small village of Qaanaaq, Northwest Greenland, and this year was not an exception.

This summer, on August 3, we organized a workshop in collaboration with locals and it was a blast (at least in our opinion). Moreover, this time we had the youngest audience ever, because many families came all together. In total, around 40 people and a film crew from Japan gathered in the local school building to listen to presentations by 5 members of our expedition (Fig. 2). This was not only an opportunity to explain what kind of research the expedition had been conducting, but also allowed us to exchange information with the locals. In addition, during coffee breaks, some valuable interviews could be conducted with locals.

In the beginning, our key local supporter, Ms. Toku Oshima, introduced us to everyone. Then, the leader of our expedition, Prof. S. Sugiyama (ILTS, HU) briefly outlined the key objectives of field observations and expressed concerns about the potential threat from waste-management practices in the village. Afterwards, Assoc. Prof. E. Podolskiy (ARC, HU) played sounds of ice and animals recorded around Qaanaaq and used to understand otherwise unseen environmental dynamics. Later, M.Sc. candidate T. Imazu (GSES, HU) told about the Qaanaaq ice-cap melting and runoff monitoring, which strongly affect the strategically important road between the airport and the village. Next, Ph.D. candidate M. Ogawa (GSES, HU) presented her work on seals’ diet and the ongoing bio sampling effort, aiming to understand migration of pollutants through the tropical chains. Finally, historical photographs taken in the region (from the 1970s) and shown by Dr. R. Kusaka (ILTS, HU) were welcomed with a greatest interest and some participants could recognize their relatives or even themselves.

Thanks to a simultaneous translation to Greenlandic and earlier rehearsals aiming to find the right words, our communication with locals was smooth and easy (Fig. 3). With kids playing in the room, the atmosphere was relaxed and joyful. On top of everything, we even got a giant Arctic Char as a present, which we grilled for dinner (Fig. 4). We are certainly looking forward to this kind of event next year again! Let’s see if the fish will be even larger!

In 2015 and 2016, the glacier outlet rivers flooded and destroyed an important road connecting the village and airport. The disasters were caused by intensive glacier melting as well as heavy rain events. To better understand the impact of climate change on the society of Qaanaaq as well as the glacier, we have measured river discharge since 2017. This summer, we measured discharge 54 times (Fig. 1), while the water level was continuously monitored with pressure sensors. We also installed acoustic and infrasound recorders to find relationships between the measurements and discharge. During the campaign this summer, flooding and destruction of the road occurred twice in July and August (Fig. 2). We work on the collected data to contribute to the prediction and mitigation of such disasters.

On the glacier, we have been monitoring the mass balance and flow velocity for more than 10 years since 2012 (Fig. 3). In 2022, we started drone survey to analyze glacier changes from high-resolution images and digital elevation models (Fig. 4). Since the ice temperature of Qaanaaq Glacier is below 0°C, meltwater does not penetrate into the glacier and forms channels on the glacier surface. One of the objectives of the drone survey is to analyze the formation and development of these channels (Fig. 5). We have succeeded six drone flights, covering the area from the terminus to the upper reaches of the glacier. Under the influence of relatively fine weather conditions, intensive melt, channel formation and ice darkening due to glacial microbes were observed in July. High resolution images should help us to understand the mechanism of rapid glacier changes.