Calving dynamics at Tunabreen, Svalbard, published in Annals of Glaciology

Annals of Glaciology has recently published our work examining calving dynamics at a tidewater glacier in Svalbard (click here to see article). In the study, we use time-lapse images captured every 3 seconds to document and analyse calving events at Tunabreen that occurred over a 30-hour period in August 2015.

A time-lapse camera installed at Ultunafjella, overlooking the calving front of Tunabreen (August 2015)

Our time-lapse camera installed in the field, overlooking the terminus of Tunabreen, a tidewater glacier in Svalbard. We captured images every 3 seconds over a 30-hour period in August 2015, from which we could distinguish calving events in high levels of detail.

In total, we acquired 34,117 images. Compiled together, these images produced a sequence that we distinguished 358 individual calving events from. We could also discern the style of each calving event, inferring the controls on calving at this particular glacier front.

Calving at Tunabreen was characterised by frequent events during our monitoring period, with 12.8 events occurring every hour on average. Most calving events were small in magnitude, relative to those observed at other tidewater outlets such as those in Greenland (e.g. James et al., 2014), and other tidewater glaciers in Svalbard (e.g. How, 2018).

Fig 3 from How et al. (2019)

All documented calving events and styles observed at Tunabreen, first distinguished in the image plane (left) and subsequently georectified to extract real coordinates and compare to ice velocity (right) (Figure 3 from How et al., 2019)

Five calving styles were observed – waterline events, ice-fall events, stack topples, sheet topples, and subaqueous events – based on the relative size and mechanism of failure. A high majority of calving events (97%) originated from the subaerial section of the ice cliff, despite the fact that 60–70% of the terminus is below sea level. Subaqueous calving events were very rare, with only 10 observed over our monitoring period. The rarity of subaqueous events indicates that ice loss below the waterline is dominated by submarine melting, with the only local development of projecting ‘ice feet’.

Over two-thirds of observed calving events occurred on the falling limb of the tide. suggested that tidal level plays a key role in the frequency of calving events. Calving events were also roughly twice as frequent in the vicinity of meltwater plumes compared with non-plume areas, indicating that turbulent water promotes temrinus instability. The presence of a ~ 5 m undercut at the base of the glacier further supports the idea that ice is being excavated from below the waterline. 

An example of a subaqueous calving event at Tunabreen, occurring in the plume area. The section of ice front shown is approximately 350 m, and the iceberg is 40 m wide

An example of a subaqueous calving event at Tunabreen, captured using our time-lapse camera. The section of ice front shown is approximately 350 m, and the iceberg is 40 m wide

We conclude that, based on the observations, calving rates at Tunabreen for this observation period may simply be paced by the rate of submarine melting. Similar dynamics have also been observed at other tidewater glaciers in Svalbard (e.g., Chapuis and Tetzlaff, 2014; Pȩtlicki and others, 2015), Greenland (e.g., Medrzycka et al., 2016) and Alaska (e.g., Bartholomaus et al, 2015). This being the case, the inference of calving rate from submarine melt rate would greatly simplify the challenge of incorporating the effect of melt-under-cutting in predictive numerical models; at least for this type of well-grounded, highly fractured glacier.

To read more about this research, please check out our paper published in Annals of Glaciology.

A dummies guide to… my PhD thesis on glacier dynamics

Recently my PhD thesis was made available online through the Edinburgh Research Archive, titled ‘Dynamical change at tidewater glaciers examined using time-lapse photogrammetry’. The thesis is 342 pages long which would be a marathon to get through for anyone, so here is a short synthesis.


In a nutshell

Title: Dynamical change at tidewater glaciers examined using time-lapse photogrammetry

Goal: To understand processes linked to dynamical change at tidewater glaciers.

Three main aims:
1. Examine subglacial hydrology and its influence on glacier dynamics at Kronebreen, a fast-flowing, tidewater glacier in Svalbard
2. Investigate controls on terminus conditions and calving processes at Tunabreen, a surge-type, tidewater glacier in Svalbard
3. Develop a suite of photogrammetry tools for obtaining measurements from oblique time-lapse imagery

Techniques used: Monoscopic time-lapse photogrammetry, hot water borehole drilling, bathymetry surveying, satellite feature-tracking, passive seismic monitoring, melt/runoff modelling


Acquiring data from the field

Me at camera site 8b, Kronebreen, Svalbard (May 2015)

An example of one of our time-lapse cameras, installed at Kronebreen

High-detail monitoring of glacier termini is challenging. We decided to employ time-lapse photogrammetry as our primary technique in this study given that it can provide high-resolution data acquisition (e.g. 1 image every 3 seconds, over 24 hours) as well as appropriate acquisition rates for longer-term monitoring where needed (e.g. 1 image every hour over the course of a melt season). Therefore we can acquire different temporal frequencies depending on which aspects of the glacier system we want to examine.

Between 2014 and 2017, we deployed 7 – 14 time-lapse cameras at two glaciers in Svalbard (Kronebreen and Tunabreen) to monitor various aspects of the glacial system – ice flow, terminus retreat, supraglacial lake drainage, meltwater plumes, and local fjord circulation. We combined the findings from these images with other datasets (e.g. borehole measurements, bathymetry surveys) in order to examine dynamical change at a high level of detail.


Finding #1: Spatial variation in Kronebreen’s ice flow is primarily controlled by meltwater routing at the glacier bed

From our time-lapse images over the 2014 melt season, along with borehole data analysis, melt/runoff modelling and hydropotential modelling, we found that spatial variations in ice flow at Kronebreen were primarily controlled by the location of subglacial meltwater channels.

Efficiency in subglacial water evacuation varied between the north and south regions of the glacier tongue, with the north channel configuration draining a large proportion of the glacier catchment through persistent channels, as indicated by hydropotential modelling. Channel configurations beneath the south region of the terminus were vastly different, with rapid hydrological changes evident and cyclic ‘pulsing’ suggested from the observed meltwater plume activity.

These differences in subglacial hydrology are reflected in ice flow, with faster velocities experienced in the south region of the glacier, facilitated by enhanced basal lubrication and sliding. Two speed-up events were observed at the beginning of the 2014 melt season, the second being of significant importance given that it occurred at the end of the melt season and enabled fast flow through the winter season. It is suggested that this event was caused by an abnormal high rainfall event which overwhelmed an inefficient hydrological regime entering its winter phase. This phenomena highlights that the timing of rainfall events at tidewater glaciers is fundamental to their impact on ice flow.

The Cryosphere Kronebreen maps

Sequential velocity maps (left) and velocity change maps (right) of Kronebreen showing the first of two speed-up events experienced during the 2014 melt season.


Finding #2: Terminus stability is inherently linked to both atmospheric and oceanic variability at Tunabreen. In particular, calving activity is primarily facilitated by melt-undercutting

Terminus conditions at Tunabreen were examined on two differing temporal scales:

  1. Over a one month period in peak melt season using time-lapse images acquired every 10 minutes
  2. Over a 28-hour period in August 2015 using time-lapse images acquired every 3 seconds

Over the one-month observation period, the terminus retreated 73.3 metres, with an average retreat rate of 1.83 metres per day. The frontal ablation rate fluctuated between 0 and 8.85 metres per day, and 1820 calving events were recorded of which 115 events were simultaneously detected from passive seismic signatures recorded in Longyearbyen. Overall, strong links were found between terminus position changes and both sea surface temperature and air temperature, suggesting that atmospheric forcing plays a larger role in terminus stability than previously considered.

Calving events at Tunabreen over a 30-hour period in August 2015, captured using high-resolution time-lapse photography (one photo every three seconds). Calving events are categorised as subaerial (i.e. ice falling from the front above the waterline), subaqueous (i.e. ice breaking off from the front beneath the waterline), both (i.e. large calving events which contain both subaerial and subaqueous originating ice) and unknown (caused by concealment or poor visibility).

Calving events at Tunabreen over a 28-hour period in August 2015, captured using high-resolution time-lapse photography (one photo every three seconds). Calving events are categorised as subaerial (i.e. ice falling from the front above the waterline), subaqueous (i.e. ice breaking off from the front beneath the waterline), both (i.e. large calving events which contain both subaerial and subaqueous originating ice) and unknown (caused by concealment or poor visibility)

Calving activity at Tunabreen consists of frequent events, with 358 calving events detected from the 28-hour, high-frequency time-lapse sequence (i.e. 12.8 events per hour). The majority of these calving events (97%) occurred above the waterline despite the fact that 60-70% of the terminus is subaqueous (i.e. below the waterline). This suggests that ice loss below the waterline is dominated by submarine melting, rather than the break off of large projecting ‘ice feet’.  In addition, calving events are twice as frequent in the vicinity of the meltwater plumes, with visible undercutting (approximately 5 metres) revealed from the bathymetry side profiles. Overall, this suggests that enhanced submarine melting causes localised terminus instability at Tunabreen.


Finding #3: PyTrx is a viable Python-alternative toolbox for extracting measurements from oblique imagery of glacier environments

PyTrx velocities

An example of PyTrx’s capabilities in deriving surface velocites at Kronebreen, Svalbard. Velocities are calculated from the image using a sparse feature-tracking approach, with unique corner features identified using Shi-Tomasi corner detection and subsequently tracked using Optical Flow approximation. In this example, 50 000 points have been successfully tracked between an image pair from Kronebreen, producing a dense collection of velocity points.

Time-lapse photogrammetry is a growing method in glaciology for providing measurements from oblique sequential imagery, namely glacier velocity. When we began processing our time-lapse images, we found that there were few publicly available toolboxes for what we wanted and the range of their applications was relatively small. For this reason we decided to develop PyTrx, a Python-alternative toolbox, to process our own data and also aid the progression of glacial photogrammetry with a wider range of toolboxes.

PyTrx is an object-oriented toolbox, consisting of six scripts that can be used to obtain velocity, area and line measurements from a series of oblique images. These six scripts are:

  1. CamEnv: Handles the associated data with the camera environment, namely the Ground Control Points (GCPs), information about the camera distortion, and the camera location and pose
  2. DEM: Handles data related to the scene, or Digital Elevation Model (DEM)
  3. FileHandler: Contains functions for reading in data from files (such as image data and calibration information) and exporting output data
  4. Images: Handles the image sequence and the data associate with each individual image
  5. Measure: Handles the functionality for calculating homography, velocities, surface areas and distances from oblique imagery
  6. Utilities: Contains the functions for plotting and interpolating data

PyTrx has been used to process the data presented previously, and is freely available on GitHub with several example applications also. These examples include deriving surface velocities and meltwater plume footprints from time-lapse images of Kronebreen, and terminus profiles and calving event locations from time-lapse images of Tunabreen.


Related links

This thesis is freely available to download from the Edinburgh Research Archive

How et al. (2017) The Cryosphere – Examining the subglacial hydrology of Kronebreen and its influence on glacier dynamics 

How et al. (In Review) Annals of Glaciology – Observations of calving styles at Tunabreen and the role of submarine melting in calving dynamics

How et al. (2018) Geoscientific Instrumentation, Methods and Data Systems – Presenting the PyTrx toolbox and its capabilities with oblique imagery of glacial environments

PyTrx – PyTrx toolbox code repository, hosted on GitHub

What is going on at Tunabreen?

Tunabreen is a tidewater glacier in Svalbard that has recently been displaying some exciting activity. It is known as a surge-type glacier, with discrete periods where it flows markedly faster and slower. Tunabreen entered a fast-flowing phase in December 2016, which is ongoing at the time of writing. The nature of this fast-flowing phase is atypical for Tunabreen though, throwing into question whether this phase is associated with surge dynamics. What is going on at Tunabreen?!

Tunabreen is an ocean-terminating glacier on the west coast of Svalbard. This glacier is particularly special because of its unique set of dynamics. A large number of the glaciers in Svalbard are known as surge-type glaciers. A surge-type glacier undergoes periods of fast-flow followed by very slow, inactive phases. The nature of this surging pattern is due to the glacier’s inefficiency in transferring mass from its upper regions to its terminus (Sevestre and Benn, 2015). It is an internally-driven process. The trigger of this process is unrelated to external influences (i.e. changes in air temperature, ocean temperature, and precipitation).

Time-lapse at Tunabreen using one image per day

Time-lapse images from the front of Tunabreen. This glacier terminates into a large fjord called Tempelfjorden, hence it is referred to as a marine-terminating glacier. This time-lapse image sequence was constructed using one image per day between July-August 2016. This work is part of Calving Rates and Impact On Sea level (CRIOS) project at UNIS.

Tunabreen is one of few glaciers in Svalbard to have been observed to undergo repeated surge cycles. It has surged in 1870, 1930, 1971, and between 2002-2005. We know these surges happened because each surge phase left a pronounced ridge on the seabed which defines the surge extent (Flink et al., 2015). As these surges have been spaced 30-60 years apart, the next surge was not expected for quite a while (at least until 2030).

Tunabreen was a very slow-moving glacier between 2005 and 2016, flowing between 0.1-0.4 metres per day (m/day). These velocities were largely derived from sequential satellite imagery. Distinct glacial features were tracked from image to image to determine surface velocities on the glacier. The highest velocities (0.4 m/day) were limited to the terminus area, with very little movement (0.1 m/day) in the upper section of the glacier tongue. It was often difficult to track glacial features from image to image because the glacier was moving so slowly.

A marked speed-up was initially observed at Tunabreen in December 2016. The entire glacier tongue suddenly flowed faster. The terminus flowed >3 m/day and velocities in the upper section increased to 0.3-2.0 m/day. This speed-up continues at the time of writing this blog post (March 2017). It is a dramatic difference from the months and years prior to this event. 

Speed-up at Tunabreen. Source: St Andrews Glaciology.

The speed-up at Tunabreen shown from feature-tracking through TerraSAR-X satellite images (from Adrian Luckman, Swansea University). Luckman also tweeted two images from this sequence here which nicely show the difference between 2015 and 2016. Source: St Andrews Glaciology.

So, is this a surge? is the question on everyone’s lips now. In short, we don’t know at the moment and this is a difficult question to answer with the short amount of time that we have witnessed these changes at Tunabreen. At the time of writing, there are 4 key observations that need to be considered:

  1. The timing of this speed-up coincides with record-high temperatures and precipitation for a winter season in Svalbard (as stated in this article by Chris Borstad, a glaciologist at UNIS). This could have had a significant influence on the presence of water at the bed of the glacier, which is understood to lubricate the interface between the ice and the underlying bedrock. This, in turn, promotes sliding and may also cause the glacier to flow faster.
  2. This winter, sea ice did not form in Tempelfjorden and the fjord area directly adjacent to the glacier front. Sea ice and melange is understood to provide a back-stress against the front of a glacier. This acts as an opposing force to ice flow. Without the presence of sea ice, this opposing force is absent at the front of Tunabreen. Lack of sea ice was also observed in the winter of 2015 (as noted here in a previous blog post).
  3. The spatial pattern of this speed-up propagated in an upward fashion i.e. an increase in velocity first occurred at the front of the glacier, with subsequent velocity changes progressing up the glacier tongue. The abundance of crevasses on the glacier surface has increased, with the crevasse field extending much further up the glacier tongue than previously. Also, the terminus has advanced roughly 400 m since December 2016, as shown from the sequence of Sentinel images tweeted by Adrian Luckman (and displayed in a post by St. Andrews Glaciology). These observations are indicative of surging dynamics, as stated by Sevestre and Benn (2015).
  4. This speed-up has occurred 12 years after the previous surge (2002-2005). Surges at Tunabreen have previously been spaced 30-60 years apart from one another. The next surge was not expected until at least 2030. If this speed-up is associated with surge dynamics then it has occurred much earlier than anticipated.
Tempelfjorden. This year we unfortunately could not visit Tempelfjorden and Tunabreen glacier with the students because of the lack of sea ice. Sea ice normally forms in Tempelfjorden up to the ice front over the winter, but this year it has not formed. This also happened in 2006 and 2012. For the first time ever though, there is no sea ice directly in front of Tunabreen, which will have massive repercussions for the glacier's dynamics

Tempelfjorden in March 2015. Sea ice normally forms in Tempelfjorden up to the ice front over the winter, but it did not form in 2015 and 2016. This also happened in 2006 and 2012. As well as having large implications for the dynamics of Tunabreen, this has also impacted on snow scooter routes across Svalbard. The sea ice in Tempelfjorden has previously been used as a major scooter route for tourist groups and for transporting goods.

These observations can be used as arguments for and against this speed-up being associated with surge dynamics. Whilst the behaviour of the glacier indicates that this may be associated with surge dynamics, there have also been significant changes in external factors which could have played a crucial role in this speed-up. It is important to continue monitoring changes to better understand the processes behind the abnormal behaviour at Tunabreen. It will be interesting to see if this speed-up is sustained through the spring of 2017, and to see how much the terminus will continue to advance into Tempelfjorden. One thing is for certain: all eyes will be on Tunabreen and what it does next!

Tunabreen in March 2017

The front of Tunabreen in March 2017. I was lucky enough to visit Tunabreen earlier this month as part of the Glaciology course that runs at UNIS each year. It was incredible to see this glacier again. We have time-lapse cameras positioned on the mountain ridge (Tunafjell) that is visible in this picture. Hopefully they will give us some insight into the dynamics associated with this speed-up.


Further Reading

St. Andrews Glaciology blog: Unexpected ‘surge’ of a Svalbard tidewater glacier

UNIS post by Chris Borstad on the changes at Tunabreen

Sevestre and Benn (2015) – A comprehensive study on surge-type glaciers and their distribution around the world.

Flink et al. (2015) – Past surge extents at Tunabreen determined by topographic features on the sea bed, derived from multibeam-bathymetric surveying over Tempelfjorden.

Tweets by Adrian Luckman showing the speed-up from TerraSAR-X imagery and Sentinel imagery

Using meltwater plumes to infer subglacial hydrology at tidewater glaciers

PhD update: January 2017. Meltwater plumes are the upwelling of fresh water in front of a tidewater glacier. These are known to influence submarine melt rates, which are suggested to have a significant impact on the calving rate of glaciers that terminate in sea water. Recent work has suggested that meltwater plumes can also be used to infer the subglacial hydrology at the front of a glacier.

At land-terminating glaciers, water is evacuated via flow outlets which form large rivers on the adjacent land. It is therefore relatively straightforward to measure the amount of water leaving the glacial system. Things are a bit more complicated at glaciers which terminate in water (i.e. a fjord, sea, or ocean). Fresh water exits from the glacier at depth and interacts with the salty seawater. The fresh water moves upwards due to the density difference between freshwater and saltwater, forming a turbulent column of mixing water. This is a meltwater plume (and can also be referred to as a ‘submarine plume’, or simply just a ‘plume’).

An example of a meltwater plume at Tunabreen, a tidewater glacier in Svalbard

An example of a surfacing meltwater plume at Tunabreen, a tidewater glacier in Svalbard. Note the distinctive shape and the dark colour (indicating sediment content) of the surface expression.

The freshwater in a meltwater plume will continue to flow up through the water column and entrain surrounding saltwater until it is thoroughly mixed (i.e. there is no difference in the density between the plume and the surrounding water). At this point, a meltwater plume will reach its neutral buoyancy and the water will cease flowing upwards and flow horizontally away from the glacier front.

A meltwater plume can reach the sea surface if the neutral buoyancy exceeds the depth of the fjord. The surface expression of a meltwater plume is normally very distinctive, distinguished by its sediment-laden colour and turbulent flow away from the glacier. We have lovely images of meltwater plume activity at Tunabreen, a tidewater glacier in Svalbard, showing a surfacing plume which has entrained very rich red/brown sediment.

The neutral buoyancy point of a meltwater plume is influenced by a number of factors:

  1. The temperature/density difference between the freshwater in the plume and the surrounding saltwater
  2. The geometry of the fjord, such as how deep it is
  3. The stratification of the surrounding saltwater
  4. The rate at which meltwater is exiting the glacier (also referred to as discharge)

The first three of these listed influences undergo relatively little change compared to discharge over short time-scales (e.g. a summer season). Assuming this, the activity of a meltwater plume can be used as a signal for the rate at which meltwater is exiting a glacier over the course of a melt season.

Meltwater typically exits into a fjord/sea/ocean at the bed of a glacier. The meltwater can either be directed through a given number of big channels or a series of intricate, small cavities. Channels can typically accommodate large volumes of meltwater, hence they are known as an efficient drainage system. Linked cavities are not as effective at transporting meltwater and tend to hold water at the bed for much longer durations, so they are aptly referred to as an inefficient drainage system.

Kronebreen (centre) viewed from the west. Kronebreen shares its southern (right) margin with Kongsvegen, a slow-moving surge-type glacier that has been fairly inactive for the past couple of years. The glacier adjacent to Kronebreen, separated by the mountain Collethøgda (left), is called Kongsbreen. Kongsbreen has been retreating from the fjord onto land since approximately 2014 (September 2016)

A meltwater plume at the front of Kronebreen, a fast-flowing tidewater glacier in Svalbard. The surfacing plume  is situated on the north side of the plume (left side of the terminus in this image). This plume entrains sediment which gives it a red/brown colour. A plume also surfaced intermittently on the south side of the terminus during the melt season of 2014 (not pictured here). Photo taken: September 2016.

Timeline of surfacing plume activity at Kronebreen, Svalbard, monitored from time-lapse imagery. Plumes P1, P2 and P3 were present at the north side of the terminus, with P1 being active for the entire monitoring period (gaps are where there was no visibility in the images). Plume P4 surfaced at the south side of the terminus, showing intermittent activity throughout the melt season.

Timeline of surfacing plume activity at Kronebreen, Svalbard, monitored from time-lapse imagery. Activity began on the 23 June and continued through till the end of September. Plumes P1, P2 and P3 were present at the north side of the terminus. P1 (pictured in the above image) was active for the entire monitoring period (gaps are where there was no visibility in the time-lapse imagery). Plume P4 surfaced at the south side of the terminus, showing intermittent activity throughout the melt season.

An efficient drainage system can quickly channel a large volume of meltwater into the adjacent sea water. It is therefore likely that the neutral buoyancy of a meltwater plume from an efficient drainage system can exceed the depth of the fjord, so the plume will surface and will be visible. An inefficient drainage system is much more limited in the rate at which it can deliver meltwater into the adjacent sea water. It is therefore likely that the neutral buoyancy of a meltwater plume from an inefficient drainage system will be at depth, so the plume will not surface and will not be visible. We can thus infer what type of drainage system is present at the front of a glacier by monitoring meltwater plume activity over short durations.

We have been monitoring meltwater plume activity at the front of Kronebreen, a fast-flowing tidewater glacier in Svalbard. Two sets of plumes were present over the 2014 melt season, on the north and south side of the terminus. It is assumed here that a meltwater plume is likely to surface in the fjord if a channel is active based on the known fjord depth (∼80 m) and modelled runoff outputs. The set of plumes on the north side of the terminus persistently surfaced throughout the melt season, whereas the plume on the south side only surfaced intermittently.

A plume may not be able to consistently surface because meltwater is not leaving the glacier through a stable efficient drainage system. This could suggest that two different drainage systems preside at the north and south side of the glacier – a stable efficient drainage system on the north side, and an unstable system that switches between efficient and inefficient drainage on the south side.

Velocity map of Kronebreen over an 11-day period in April 2014 (Luckman et al., 2015)

A velocity map of Kronebreen over an 11-day period in April 2014 (Luckman et al., 2015). These velocities are derived from feature tracking between image pairs, and these images are TerraSAR-X satellite images. Higher surface velocities are present at the central/south side of the terminus compared to the north side. This is possibly related to a difference in subglacial drainage beneath these two regions. Source: UNIS.

In this situation, you would expect to see other differences between the north and south side of the terminus such as surface velocity. A large amount of subglacial meltwater is in contact with the bed in an inefficient drainage system, which enhances lubrication at the bed and promotes ice sliding. In an efficient drainage system, the water is channelled through a discrete area of the glacier and thus there is less basal lubrication as a smaller amount is in contact with the bed.

Surface velocities over the 2014 melt season show a distinct difference between the north and south side of the glacier terminus – the south is much faster flowing than the north, with the south exceeding velocities of 4 metres per day whilst the north remains relatively slow (see an example velocity map above). It is likely that a difference in drainage efficiency could facilitate this difference in surface velocities. The presence of an inefficient drainage system at the south side of the glacier tongue may be promoting faster velocities.

This idea is being further explored with additional datasets to better understand glacier hydrology and dynamics. The main take-home message from this post is that meltwater plume activity could be a reliable signal for meltwater outflow. This activity can be effectively monitored using time-lapse photography. Observations of plume activity can help us to diagnose the nature of subglacial drainage beneath tidewater glaciers, which is not accessible for direct measurements at this time. Kronebreen appears to have two different drainage systems active near the glacier terminus, as reflected in the differing plume activity, and this could be facilitating fast velocities in discrete areas of the glacier.


Further reading

Slater et al., 2017 – A newly-published study looked at meltwater plume activity at Kangiata Nunata Sermia (KNS) in Southwest Greenland using an in-situ time-lapse camera. They predicted from model simulations that a meltwater plume from a single channel should be able to surface in the adjacent fjord water, knowing the rate of discharge through the drainage system. However, the time-lapse imagery showed that the meltwater plume was only visible for brief periods throughout a melt season (May to September 2009). They argued that a plume was not consistently surfacing because meltwater may not leaving the glacier through a stable efficient drainage system. An efficient drainage system may not be able to persist at the front of KNS because it could be repeatedly disrupted by basal deformation, which is facilitated by the fast-flowing nature of the glacier. This paper has been neatly summarised by ice2ice.

Time-lapse sequences from Kronebreen. Note the visible plume activity seen from cameras 1 and 2 through the melt season.

PhD Update: September 2016

I have been in Svalbard (again) for most of September, collecting images from our 14 time-lapse cameras that we have based in Kongsfjorden and Tempelfjorden. We haven’t seen these cameras since May 2016 (Kongsfjorden cameras) and August 2015 (Tempelfjorden cameras) so it was quite nerve-racking to go back and see if everything had worked. We had a couple of disappointments but generally the retrieval was a success, with approximately 130,000 photos collected in total.

Ten time-lapse cameras were deployed in Kongsfjorden last May (click here for more info on the deployment). Eight of these were installed on Collethøgda, overlooking Kronebreen, a fast-flowing marine-terminating glacier at the end of the fjord.  It is hoped that the close array of images from these cameras can be used to generate three-dimensional time-lapse sequences using a technique called Structure-from-Motion (SfM) which uses images from multiple angles to generate 3D point clouds of a target.

The other two cameras were installed by Kongsbreen and Kongsvegen, the two glaciers adjacent to Kronebreen. The data from these cameras form part of a longer-term project to monitor glaciers in the Kongsfjorden area. It was of particular importance to the influence of submarine melting on glacial retreat in this area.

Our camera at Kongsbreen... survived and still working! (September 2016)

Our camera at Kongsbreen… survived and still working! When were first started installing cameras in Svalbard, we would bolt them into the bedrock and use guide wires to stabilise them. Over time we have learnt that building cairns around the tripod legs is just as effective and takes much less time. We had a particularly long time around this camera site in May to build a large cairn… and do some sunbathing.

Due to bad weather, it proved difficult to access the camera sites and were limited to only two days of helicopter time to retrieve data. We had hoped to have enough time to survey and maintain each of the cameras so that they could run over the winter season, but alas! that is the beauty of fieldwork – you have to work with the weather you have. We managed to retrieve all of the memory cards from the cameras in the end, but couldn’t complete the camera surveying.

Previously we had deployed 7 time-lapse cameras in 2014 and 8 cameras in 2015, so we knew we were being ambitious with 10. In total, 6 worked through the entire season collecting images either every 10 minutes or every 30 minutes. We have had better success in the past (5/7 in 2014 and 6/8 in 2015) so we were a little disappointed that we weren’t able to beat our personal best! All of the problems were related to the power supply – temperamental solar controllers did not recharge the batteries from the solar panels, and there were poor connections in the camera boxes that had developed over the duration in the field.

Overall, 48 000 images were collected from the cameras at Kongsfjorden – we have a good sequence from Kongsbreen showing multiple submarine plumes creating inlets in the ice front, good coverage over the front of Kronebreen to look at calving activity and surface velocities over the summer season, and a good sample dataset to begin looking at constructing 3D SfM time-lapse sequences.

As the weather was so limiting on our helicopter time, we also accessed the shoreline next to Kronebreen by boat, where we set up our 4K video camera (left over from the CalvingSEIS project last month) to record calving activity. We recorded an 11-hour 4K video sequence which provides some awesome close-ups on isolated calving events such as the one in the video below.

This work is so important to ensure the safety of tourists and scientists alike. Currently the minimum safe distance from a calving front is 200 metres, but accidents do still happen. The distance that ice can be thrown from a calving event is thought to be controlled by the height of the calving origin and the impact with the water. With this in mind, the minimum safe distance should be different for each calving glacier front in Svalbard. We hope that we can track projectiles from such calving events in this sequence to re-assess the distance that boats should be from calving  glacier fronts in Svalbard. It is likely that glacier calving fronts require different categories of risk based on calving activity (frequency and volume), ice cliff height and ocean temperature.

Preparing for our helicopter ride over to Tunabreen (September 2016)

Preparing for our helicopter ride over to Tunabreen. Mats (pilot, left) is ‘composing himself for the flight’ whilst Harold (technician, centre) is doing routine checks on the helicopter. Chris Borstad (UNIS, right) joined us on this trip to check the time-lapse cameras and survey the glacier surface using a laser scanner to look at crevasse propagation rates in the upper section of the glacier tongue.

After finishing in Kongsfjorden, we flew back from Ny Ålesund to Longyearbyen and got a lucky opportunity to fly to Tunabreen and collect data from 4 time-lapse cameras that have been there for over a year now (see here for information on the installations and other work in this area). They were meant to be collected in September 2015, but the plan had to be abandoned due to poor weather. We also planned to retrieve them at the beginning of this year, but the warm winter had left Tempelfjorden first without sea ice for snow scooter transport and then with too much sea ice for the boat season.

After some manic negotiations with the Sysselmannen (Governor of Svalbard), we got permission for two helicopter landings on Ultunafjell, where the time-lapse cameras were installed. When flying over, it was impressive to see how much the calving front has changed, even over the past couple of months. Normally there is one consistent submarine plume at the west side of the calving front (near to the camera in the image below) that is active throughout the melt season, creating an inlet in the calving front. This year though, it appears that a second strong plume at the east side of the calving front  has created a marked inlet (see far inlet in the image below). The upper section of the glacier tongue has also changed, with the crevasse field extending much further up-glacier than in previous years. Both the growth of the crevasse field and the change in submarine plume activity could indicate a change in the subglacial conditions at Tunabreen.

The calving front of Tunabreen (September 2016)

The calving front of Tunabreen. The muddy water in front of the glacier is where the submarine plume has been strong enough to entrain sediment from the sea bed to the surface through turbulent mixing of freshwater and seawater. This promotes melting of the ice below the waterline, which has created two inlets in the calving front this year – the first is closest to the camera with a very visible plume adjacent, the second is the marked bay on the far side.

Three of the cameras on Ultunafjell were entrained on the calving front and lower section of Tunabreen, all of which had captured images till now. Unfortunately, due to unknown circumstances, two of the cameras were taking images that were out of focus when they came back on in the spring (after hibernating over the winter). It is likely that either someone has been up there, taken a look at the cameras and accidentally knocked the focusing ring on the lenses; or that high winds caused vibrations in the camera box that gradually shifted the focusing ring.

It’s a new set of circumstances for us anyway! From now on, we will fix the focusing ring in position by taping each lens. Luckily, one camera did not experience focus drift so we have three sets of images from August till November 2015, and one set of images from May to September 2016. This is plenty to work with and will give us a nice dataset to extract velocities and calving rate from.

The fourth camera is positioned further up the ridge, looking at the upper section of the glacier tongue where crevasses are begin to form and propagate. It was installed to monitor an array of strain meters that were set out on the glacier surface, measuring the rate at which crevasses were opening and the rate of longitudinal stretching. The relative distance between each strain meter in the images can be used to ensure that the strain meters are accurately measuring changes at the glacier surface. This camera has captured images every 10 minutes from August 2015 till September 2016, which is a great success. The camera has been surveyed and will now continue to take photos through the rest of 2016 into 2017, providing a complimentary dataset for Chris Borstad and the University Centre in Svalbard (UNIS) to use with other on-glacier instruments.

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Sample image from the time-lapse sequence at the upper section of Tunabreen. These images monitor an area that is 497.6 m x 331.7 m. The strain meters are difficult to find in this image, with each strain meter box only represented as a 2 x 2 pixel square!

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A close-up of the strain meters. The people in the image are myself and Doug Benn, part of the team that installed the seven strain meters on Tunabreen in August 2015.

So, in total, we have collected approximately 130,000 images in this month, providing us with a third consecutive year of time-lapse data at Kronebreen, and new insights into processes at Tunabreen and Kongsbreen. From these images, we should be able to extract a record of surface velocities, calving rate, submarine plume activity and crevasse propagation from each glacier. I am now back from Svalbard for this rest of this year to begin processing this data and enjoy Edinburgh in the autumn/winter season.

A tame ptarmigan at Tunabreen (September 2016)

A ptarmigan at Tunabreen. This little guy was walking along with me to visit our third time-lapse camera. Ptarmigans often nest around our cameras at both Tunabreen and Kronebreen – this makes for lovely images, but is a hinderance for photogrammetry processing!


With thanks to the following for making this fieldwork possible: Richard Delf (University of Edinburgh), Jack Kohler (NP), Chris Borstad (UNIS), our helicopter pilots Mats Larsen and Harold Edorsen, our skipper Wojtek Moskal,  and all in the NP Sverdrup station in Ny Ålesund.

PhD update: May 2016

May has been a varied month beginning with returning from Svalbard. The fieldwork in Kongsfjorden was very successful, with 12 time-lapse cameras deployed at various glaciers in the area to monitor their dynamics till September 2016. No rest for the wicked when I made it back to Edinburgh though as I had to prepare for a very impromptu trip to Tromsø and present findings from the fieldwork and talk about submarine plume dynamics. Luckily for the last week of May I have been settling back into the office in Edinburgh enjoying good company and incredible weather.

The month began in Svalbard… this seems to be a running theme of most of my monthly blog posts – I begin the month in Svalbard and also end the month in Svalbard. Luckily this month is slightly different. I am not planning on going back to Svalbard till at least late July/August now so I have plenty of time to enjoy Edinburgh, which is gloriously sunny at the moment.

The fieldwork in Svalbard went very smoothly, successfully installing 12 time-lapse cameras at three glaciers in the Kongsfjorden area – Kronebreen, Kongsvegen and Kongsbreen. The installations at Kronebreen have been well documented in a separate blog post which can be viewed here. Photos from the fieldwork were also featured on GlacierHub, a site dedicated to communicating scientific research in glaciology.

Sun, sea and snow in Tromsø during my visit to Norsk Polarinstitutt

Sun, sea and snow in Tromsø during my visit to Norsk Polarinstitutt (May 2016)

After the installations in Kongsfjorden, it was hoped that we could visit our time-lapse cameras at a tidewater glacier called Tunabreen, which is a short snow scooter journey/boat ride from Longyearbyen, the main Norwegian settlement in Svalbard. We installed four cameras at Tunabreen last summer and intended to collect data and service them in March. Lack of sea ice limited our access to the glacier during the time though. Unfortunately a weather window didn’t open up this time round, so those cameras will have to be left for a while longer.

After being back in Edinburgh for a week, I had the opportunity to visit Norsk Polarinstitutt and present our observations of submarine plumes from our time-lapse images. Norsk Polarinstitutt is Norway’s governmental institution for scientific research in the Arctic and the Antarctic, which is based in Tromsø on the north coast of Norway. I’ve never been to Tromsø. It is a beautiful place and I would definitely recommend going – especially  in the winter for skiers. The settlement is surrounded by sea and mountains, very well-suited for those who want the city life but also want the outdoors close by.

I was invited to talk about glacier activity and submarine plumes in the Kongsfjorden area as part of Norsk Polarinstitutt’s efforts to better understand the impact of glacial systems on fjord dynamics and ecological activity. Glacier meltwater is generally routed through a glacier via large channels at the glacier bed. This meltwater exits the glacier either as proglacial streams in land settings, or as submarine plumes in tidewater settings. In tidewater settings, the meltwater  rises when it meets the salty fjord water because of the difference in density (due to the difference in temperature and salinity). This plume entrains sediment and additional surrounding water, which forms a visible boundary if the plume reaches the surface of the fjord.

An example of a submarine plume reaching the surface of the fjord water. This example is from Tunabreen, Svalbard, a slow-moving glacier that terminates into a large fjord system called Tempelfjorden. Note the colour difference between the plume and the surrounding water due to the difference in sediment content (August 2015).

An example of a submarine plume reaching the surface of the fjord water. This example is from Tunabreen, Svalbard, a slow-moving glacier that terminates into a large fjord system called Tempelfjorden. Note the colour difference between the plume and the surrounding water due to the difference in sediment content (August 2015).

This is not only an important process to understand in glaciology, but also has a large influence on fjord circulation and provides a rich feeding ground for birds, seals and whales as the difference in salinity stuns small living organisms in the water. Our time-lapse cameras have been monitoring  the submarine plume at Kronebreen glacier, and it is hoped that the spatial extent of the plume can be linked to ecological activity, specifically the presence of Kittiwake birds and Beluga whales in the Kongsfjorden area. This is an exciting interdisciplinary collaboration which I am so happy to be a part of. Beforehand, I never considered the significance of my time-lapse photography work beyond the reaches of the glaciology community. Hopefully something really interesting and meaningful can come from this.

And finally I end this month in Edinburgh. Work has taken a back seat as it is so warm and sunny here at the moment. Next month I intend to spend a lot of time staring at a computer screen as we begin the first implementation of PyTrx, the software we have been developing to automatically feature track glacial points through image sequences. This will be the first full month that I will spend in one place this year. Let’s hope I don’t get itchy feet.

Svalbard photography (Feb-Mar 2016)

For the past month I have been in Svalbard, demonstrating on the Glaciology course (AG-325/825) at the University Centre in Svalbard (UNIS). The course is aimed at Masters and PhD students who want a taste of the Arctic, consisting of four weeks of glaciology lectures  and weekly excursions to glaciers in the local area. I have been supporting the logistical side of the weekly excursions, with the odd bit of teaching here and there. The course ran very successfully and everyone seemed to thoroughly enjoy themselves. Here are a few photos from the course…

The sun rising in Rindersbukta. The sun first rose after the dark season in early March and has created beautiful lighting for the rest of the month (March 2016)

The sun rising over Rindersbukta, taken during the third week of the course. The sun first rose after the dark season in early March and has created beautiful lighting for the rest of the month…

...Like this. This was taken on the way back from our trip to Mohnbukta in the final week of the course.

…Like this. This was taken on the way back from our trip to Mohnbukta in the final week of the course.

Tempelfjorden. This year we unfortunately could not visit Tempelfjorden and Tunabreen glacier with the students because of the lack of sea ice. Sea ice normally forms in Tempelfjorden up to the ice front over the winter, but this year it has not formed. This also happened in 2006 and 2012. For the first time ever though, there is no sea ice directly in front of Tunabreen, which will have massive repercussions for the glacier's dynamics

Tempelfjorden. This year we unfortunately could not visit Tempelfjorden and Tunabreen glacier with the students because of the lack of sea ice (this picture was taken on a rekkie trip to examine the conditions for snow scooter travel). Sea ice normally forms in Tempelfjorden up to the ice front over the winter, but this year it has not formed. This also happened in 2006 and 2012. For the first time ever though, there is no sea ice directly in front of Tunabreen, which will have massive repercussions for the glacier’s dynamics.

During the course, I have been lucky enough to have come across four polar bears (safely and in a calm situation). This particular photo shows a male bear that we spotted in Rindersbukta. Shortly after this photo, a second bear was spotted nearby. Before this visit to Svalbard, I had only seen one polar bear (I have been coming to Svalbard since the start of 2014). This might be coincidence, but could also be related to the sea ice conditions and lack of sea ice in certain areas of Svalbard.

During the course, I have been lucky enough to have come across four polar bears (safely and in a calm situation). This particular photo shows a male bear that we spotted in Rindersbukta. Shortly after this photo, a second bear was spotted nearby. Before this visit to Svalbard, I had only seen one polar bear (I have been coming to Svalbard since the start of 2014). This might be coincidence, but could also be related to the sea ice conditions and lack of sea ice in certain areas of Svalbard. Photo credit: Nick Hulton.

Another incredible view

Another incredible view from one of our field excursions. I am often at the back of the student group on these excursions, making sure that the group is okay. I find it very relaxing being at the back as I can happily stop and take pictures like this! 

Another picture from the back of the group, in front of Hayesbreen/Heuglinbreen.

Another picture from the back of the group, in front of Hayesbreen/Heuglinbreen. The students were especially enthusiastic to get up close and personal to the glacier front! As you can probably tell, I am a very (very very very) amateur photographer. For much better photos taken in Svalbard, I would definitely recommend checking out Frede Lamo who, as well as working in the logistics department at UNIS, is a professional photographer and very (very very very) good at taking photos of Svalbard wildlife and scenery.