Below is a terrific short video examining a missing persons mystery from 1926 using glacier modelling!

A large ice island has broken off the Petermann Glacier in northern Greenland.

NASA satellite image (MODIS).

This iceberg is about twice the size of Manhattan but approximately half the size of the previous recent break-off in 2010 (blog post here).  Unlike the 2010 event the current ice has broke off further up glacier and marks a retreat of the calving front of the glacier.  The crack and rift that led to this break off has been known and observed for some time and so this event was expected in this regards.  However, the question is still being asked as to how unusual these large calving events are and whether they were caused by climate change.  Certainly we can say that these changes have not been seen for at least a 150 years (see previous post and this discussion article).  However, we can’t say for certain that these two massive calving event are a direct result of climate change.  An interesting discussion on these questions is provided in this BBC article.

The Guardian has a little interactive page where you can watch the iceberg break off in context (click here).

Glaciologist Tim Creyts provides an insightful radio interview here.

A man has been arrested for stealing 5 tonnes of 1000-year-old ice from the Jorge Montt Glacier in Chile.  The glacier ice was destined for high-end cocktail bars in Santiago to be used as ice cubes.  The BBC has a news report on the story.

Jorge Montt Glacier has been called the fastest shrinking glacier in Chile.  A retreat of ~1km was observed in just one year, this was recorded by time-lapsed cameras.  The series of 1445 photos have been used to produce a short video (shown below) of the glacier’s retreat.

Want to know how a glacier works!?  Check out this great online glacier simulator.  You can select a mountain glacier or a tidewater terminating glacier.  Experiment by changing the air temperature to see how this effects the glacier.  Click here to try it yourself.

A recent published article had a great story of how ice-flow modellers saved the day!

“Last year, a large, water-filled pocket in the Tête Rousse Glacier of the French Alps threatened to burst and flood the valley below. On an urgent request by local authorities, scientists quickly developed a model to assess whether draining the cavity would weaken the cavity roof and cause it to collapse. The model accurately predicted that draining would be safe.”  Nature Research Highlights

The subglacial cavity contained at least 50,000 mof water.  Here is a great video of people climbing into the inside of the cavity after it was artificially drained.

Another video (in French) details how they went about draining the water from the glacier.

I have just recently had an academic article accepted for publication in the Proceedings A of the Royal Society.  I love the great history of this journal, by publishing here I am very pleased to be following a long line of illustrious scientists including Paul DiracWerner HeisenbergJames Clerk MaxwellErnest Rutherford, and Erwin Schrödinger.  Within Glaciology itself many classic papers have been published in this journal such as those of John Nye.  The title of my paper is:

A Numerical Study of Hydrologically Driven Glacier Dynamics and Subglacial Flooding

I aim to do some layperson posts on this work in future blogs, but for now here is a 100 word media summary:

In this study a numerical model is developed to explore interactions between glacier dynamics and subglacial hydrology.  In line with recent observational evidence our findings suggest that subglacial drainage channels develop in response to seasonal increases in meltwater.  Water from the rapid surface-to-bed drainage of meltwater lakes in Greenland likely encounter these efficient drainage channels.  This work is an important step towards understanding the dynamic response of glaciers to changes in meltwater production and ultimately improving estimates of glacier and ice sheet contributions to current and future sea level rise.

The abstract reads as follows:

A hydrologically-coupled flowband model of “higher-order” ice dynamics is used to explore perturbations in response to supraglacial water drainage and subglacial flooding.  The subglacial drainage system includes interacting “fast” and “slow” drainage elements.  The “fast” drainage system is assumed to be comprised of ice-walled conduits and the “slow” system of a macroporous water sheet.  Under high subglacial water pressures, flexure of the overlying ice is modelled using elastic beam theory.  A regularised Coulomb friction law describes basal boundary conditions that enable hydrologically driven acceleration.  We demonstrate the modelled interactions between hydrology and ice dynamics by means of three observationally-inspired examples:  (1) simulations of meltwater drainage at an Alpine-type glacier produce seasonal and diurnal variability, and exhibit drainage evolution characteristic of the so-called “spring-transition”; (2) horizontal and vertical diurnal accelerations are modelled in response to summer meltwater input at a Greenland-type outlet glacier; and (3) short-lived perturbations to basal water pressure and ice flow-speed are modelled in response to the prescribed drainage of a supraglacial lake.  Our model supports the suggestion that a channelized drainage system can form beneath the margins of the Greenland ice sheet, and may contribute to reducing the dynamic impact of floods derived from supraglacial lakes.

Please email me if you are interested in a pre-print of the full article.

An interesting story I read on the BBC website yesterday entitled ‘Can painting a mountain restore a glacier?’.  A local community in Peru are painting a mountain white using lime, industrial egg white and water.  The aim being to change the surface albedo (a measure of how strongly an object reflects light).  Whitewashing the mountain will mean the sunlight is reflected off the surface (rather than being absorbed) and thus cooling the microclimate hopefully making conditions more favourable for the disappearing glacier.  Will this be enough to save the glacier – who knows!  A couple of degrees lower could be enough to slow or holt the decline, at least in the short-term. Of course it will not change the regional decline of glacier coverage in the Andes.

Geoengineering is the scientific term used to describe deliberately manipulating physical, chemical, or biological aspects of the Earth system.  If mitigation (reducing emissions) and adaptation (increasing capacity to cope with climate impacts) fail then large scale geoengineering may be required as a last resort to reduce major negative consequences of climate change.  A position statement on geoengineering the climate system from the American Geophysical Union (AGU) of which I belong can be found here.  Elsewhere the Royal Society of London has published a comprehensive report (details found on this page) that also advocates extreme caution in the possible use of such approaches and their feasibility while encouraging research efforts in this interesting area.