Khumbu glaciers outreach leaflets

In autumn of last year Scott Watson of the University of Leeds, and www.rockyglaciers.co.uk headed off again into the Khumbu for his PhD research, and he had the great idea to make a couple of  copies of a laminated factsheet about the Khumbu Glacier that is the focus of his study. These he left in a number of lodges in the surrounding villages.

thumbnail of Khumbu_outreach

I love the idea of getting information about what research is being undertaken on the glaciers there, and what is being found out, directly to both local residents and visitors to the region, so I quickly jumped on Scotts bandwagon and made a second factsheet for the Ngozumpa glacier, which Scott kindly dropped off for me in the Gokyo valley.

thumbnail of Ngozumpa_outreach

You can download them for yourself by clicking on the images above, and we welcome any comments on the content and style of these outreach leaflets.

 

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Lewis Glacier of old

The other week I received a lovely email from Jens Kulbe, in which he included a photograph of the Lewis Glacier on Mt Kenya taken in 1971:

Just look at it! Almost into the lake! I have heard legend of people skiing on Lewis glacier, but it certainly looks like that was a more reasonable prospect back in 1971, though not under the snow conditions in Jens’ photo probably!

Its hard to visualise the change directly as I’ve not got a modern day photo from quite that location, but in a previous blog I showed a decade of glacier change, and reported that the glacier seemed to be splitting up. That is confirmed in an aerial view of the glacier from a Pleiades satellite image taken in  February 2016 – I reckon that rock bar would necessitate some decent aerial skills to clear it on skis:

Image: Pléiades PHR1B scene of Lewis Glacier 23.02.2016. Courtesy of M. Ladner and A. Heller (Institute of Geography, University of Innsbruck, Austria).

The best way I have to visualise the change since 1971 is to look at the map below made by Rainer Prinz in 2010. It should be noted that the current (2016) glacier, as shown in the satellite image above, is now considerably smaller that in the last mapped extent shown below (2010). Its just that we have not re-mapped it recently (working on other things!), but I’d estimate that the current terminus is about 500m horizontally distant from and 100m above the lake in Jens’ photograph.

Map: from Prinz, R., Fischer, A., Nicholson, L., Kaser, G. (2011) Seventy-six years of mean mass balance rates derived from recent and re-evaluated ice volume measurements on tropical Lewis Glacier, Mount Kenya. Geophysical Research Letters, 38, L20502, doi:10.1029/2011GL049208. [pdf]
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POP Greenland

Before you get excited about a music blog, this post is about adventure and persistent organic pollutants (POPs).

Sometimes people are impressed that I’ve often worked above 4800m in Tanzania, Chile, Peru, Nepal and Kenya, usually hauling heavy loads and doing slightly uncomfortable physical scientific work, or have camped for a month in Arctic Canada, outside the range of reliable or timely rescue if things were to go awry. However, in reality these trips have been (at least 99% of the time) a rare treat and privilege to be in such wonderful places, far from the discouraging problems and demands of the modern world and instead immersed in nature with some of my favourite people.

Now I’ve gone and signed up for something that sounds really challenging: In spring 2018 I will be part of a National Geographic Explorers team doing an unsupported ski traverse of Southern Greenland. Gulp. Here is a photo of what interior Greenland is like by my friend Uwe Hoffmann:

Crossing a crevasse by Uwe Hoffmann

You can read all about our route, following the footsteps of Nansen, and preparations on the project website, and by following us on facebook, twitter and instagram. This is an adventure but with a scientific purpose: We are going to sample snow and see if it contains pesticides from lower latitudes transported up to the Arctic, and also try to determine, through atmospheric analysis where any such pollution is most likely to have come from.

This is an important issue as synthetic pesticides are resistant to decomposition in the natural environment. Instead of being broken down by biological or chemical means, they instead accumulate through the food chain, becoming more and more concentrated, especially in the fatty tissues of higher predators. These compounds have been shown to damage organ and enzyme function in the body, and inhibit reproduction.

Rachel Carsons powerful book about the impact of widespread pesticide and herbicide use in the 40s and 50s, Silent Spring, remains as relevant todays as it was upon its publication in the 1960s. While many of the chemical species she wrote about have been restricted or banned under the Stockholm convention of the 1990s, they are still found in the environment. An example that almost all of us have come across and maybe even used against mosquitos is DDT. Alternative compounds are now used in place of these banned substances. These are intended to be less harmful, but as the purpose of all these chemicals is to eradicate certain unwanted pests and plants, they are clearly associated with some level of toxicity.

Although not widely produced in the Arctic, the fact that these pollutants can survive atmospheric transport into Arctic regions is widely reported through the Arctic Monitoring and Assessment Program of the Arctic Council. They show up particularly in the marine mammals but little is known about the presence of pesticide pollutants held in the snow and firn of the icesheet. This could be important as it may be that the now-melting snow and firn will release some of the more savage contaminants used in previous decades into the hydrological cycle.

The strategy of our expedition is to:

  • traverse in April, when snowfall is still quite frequent
  • use skis rather than motorized vehicles that might contaminate the snow
  • collect 20-30 kg of surface snow
  • measure the amount of contaminants in the snow back in the laboratory in Poland
  • use global gridded atmospheric data to back calculate the airflow trajectory for each snowfall event so we can work out where the precipitation (and any pollutants it contains) is most likely to have originated from

Wish us luck, and please follow our social media channels – it helps publicise our valued sponsors that are making this scientific adventure possible.

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Testing electrical resistivity tomography (ERT) on ice and debris

Exciting! A guest blog post from Dr Sarah Thompson who spent 6 months working with us here during summer 2016. Although it wasn’t even her main project while in Innsbruck, discussions about field data and confusing results meant that we cooked up a plan to use the cold room here in ACINN to do some laboratory tests of geophysical measurements. This meant that Sarah ended up spending a lot of time battling technical difficulties in a walk-in freezer, which is never that much fun. Here is what she was up to in there:

We wanted to test the difference in resistivity signal between temperate and cold ice beneath debris layers of varying characteristics to allow us to interpret field data collected from the debris-covered Ngozumpa Glacier in Nepal.

Electrical resistivity tomography (ERT) is a geophysical tool used to image subsurface properties by measuring the electrical conductance properties of different materials. Electrical resistivity is largely controlled by the presence of water held in fractures and pores. As a result, a marked increase in resistivity occurs at freezing point. ERT techniques have been used successfully for hydrological and permafrost investigations, detecting and areas of ice and frozen ground and to identify the presence (or absence) of ice in glacial moraines. The mechanisms of electrical conduction in natural ice, such as that contained in polar ice sheets, mountain glaciers or frozen ground, are still not fully understood but measurements typically vary over several orders of magnitude, with temperate ice having a much higher resistivity than cold ice.

In late autumn of 2010 and 2014, ERT surveys were carried out on Ngozumpa Glacier to locate the ice margin at the debris-covered glacier terminus. Inversion and interpretation of ERT data collected in 2010 gave resistivity values more commonly associated with cold glacier ice. Very little is known about the thermal regime of large Himalayan debris-covered glaciers but isolated studies have suggest some glacier in the region may be polythermal. While it is feasible that the ice imaged may be cold, the ERT data are a 2-D representation of an actually 3-D distribution of electrical subsurface properties, this leads to an uncertainty in the data which is not generated by data error or noise. Also, the high contrast in resistivity within the profiles can cause the equivalence problem, specifically, the signal of the highly resistive ice could be suppressed by the thin, more conductive surface layer.

We set out to test the hypothesis a ‘debris layer of sufficient thickness and conductivity masks the highly resistive signal of glacier ice beneath reducing the resistivity to values commonly associated with cold ice or frozen sediments’.

To do this we froze a block of ice (0.8 x 1.2 m) in a plastic water butt and installed a string of temperature sensors (encased in green tubing) through the middle and edge of the block to monitor ice temperature during a series of miniaturized geophysical surveys:

A scaled electrode array was created using stainless steel nails, complete with saltwater sponges and attached to the electrode points of the cable used in the full-size field measurements:

We carried out surveys using surface debris layers of different characteristics, including coarse (left) and fine (right) grained debris:
Surveys were also conducted over cold (< -15º C) and temperate ~ 0º C bare ice, for which holes were drilled into the ice and a very small amount of salt water added to allow elected connection:

As far a possible all surveys were carried out using both cold and the temperate ice. A combination of different debris characteristics were added to the ice surface to test the effect of debris thickness, grain size, saturation and freezing on the resistivity signal from underlying temperate or cold ice.

Sarah did a phenomenal job in tedious and testing conditions and we will use the results of these hard-won laboratory studies to hopefully unravel the meaning of the field data, but as its not a side project for both of us it may take some time!

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Alpine glaciers in context

I live in the European Alps. People here are concerned about the glaciers in this region (e.g. this www.insideclimatenews.org article) and want them to stick around, for tourism, skiing, climbing, enjoyment and scenery, amongst other reasons. Unfortunately for those holding these wishes, the data on glacier change in the region, and projections of their response to foreseen Alpine temperature changes suggest that their survival outlook is gloomy (e.g. Zemp et al., 2006).

My colleagues Dr Kristin Richter and Dr Wolfgang Gurgiser put these Alpine glacier in context in an outreach exercise for school children in which the participants are given a lump of playdough and asked to distribute it across a world map according to how the glaciers and acetates of the earth are currently distributed. The last lot of students did a pretty good job as you can read in Kristins blog on the matter, and in the end the division of ice mass between the major ice sheets of Antarctic (left) and Greenland (middle) and the mountain glaciers (right) that are closer to home for most of us looks like this:

As Kristin says: “Though only small amounts of ice are stored in glaciers compared to the ice sheets, they still have been one of the main contributors to sea level rise during the last centuries. However, the glaciers in the European Alps are but a tiny fraction (less than 1%) of the small ball that represents the glaciers. Literally just a drop in the ocean.”

So, while we may miss our Alpine glaciers when they are gone, if we are concerned about how glacier melt will affect global sea level rise our eyes should be elsewhere.

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JIRP presence at AGU

The American Geophysical Union (AGU) annual Fall Meeting later this month is one of the biggest earth science meetings of the year. This year the student research projects from the Juneau Icefield Research Program (JIRP) have each prepared a poster on their scientific projects and findings to be presented t this meeting by a student representative of the group. Its a great achievement and I hope those who can attend the meeting have a great time there. If you are visiting the AGU please try to visit the posters being presented by our teams of students, which I have listed below. The name of the person presenting the poster is given in brackets after the poster title although the posters were prepared by a whole team, whose names can be found my following the title link to the abstract.

C33A-0756: Gravimetric determination of the Thickness of Taku Glacier: Impact of Glacier Thickness on Subglacial Hydrology and Potential Erosion (Hamm, Tae)

H13A-1334: Chemical Weathering on the Llewellyn Glacier, Juneau Icefield (Zaccarin, Annie)

PP31D-2330: Spatio-temporal Variation of Water Isotopes on the Juneau Icefield (Semnacher, Cezanna)

GC31C-1133: Vascular Vegetation and Soil Microbiota of Juneau Icefield Nunataks (Collins, Deirdre)

C41C-0688: Evaluating Interannual Variability of Accumulation Gradients on the Juneau Icefield (Koncewicz, Evan)

C53D-0777: Temporal Changes of Surface Elevation and Velocity of Taku Glacier, Juneau Icefield (Ooman, Brittany)

sanfran

Many JIRP faculty are also presenting at the AGU Fall Meeting, including Jason Amundson, Anthony Arendt, Billy Armstrong, Matt Beedle, Kiya Riverman, Eric Klein, Jeremy Littell, Brad Markle, Chris McNeil, Twila Moon, Allen Pope, Shad O’Neel and Martin Truffer. Have a talk to any of our former students of these faculty members to learn more about the program. Or indeed, check out the JIRP blog, which continues to post students reflections and continuing news on the website.

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Ngozumpa glacier runoff

In April this year, Costanza and I went to try and download some data from a water level guage on the Dudh Kosi Phanka and Nha, in front of the Ngozumpa glacier, operated by the Department of Hydrology and Meteorology. Unfortunately, we found that it had been dismantled – looks like someone decided they could make better use of the solar panel and the battery. To be fair, that is likely to be true!

Anyway it made me think about what data was ever collected from this guage and all I could find was  data from 2007, though there may well be more. I don’t know the full history of its installation, maintenance and data download history.

You can see some of the data below but first some information on the sensor and some caveats.

  • The sensor is a sonic ranger so it measures a distance to the water level, by using the speed of soun, and the travel time for a sonic pulse to bounce back from the water surface to the sensor.
  • This will obviously be noisy as the water surface is choppy and variable, even though its mounted over a backwash pool.
  • Readings were saved for 15 minute, 60 minute and daily values – I have not seen the program for this but I assume these are averaged values in order to filter out some of the noise.
  • This location captures runoff from the connected lakes and cathcments on the west side of the glacier, as well a the glacier.

First, I wanted to remove some of the outliers as there are some big jumps in the apparent water level in the dataset which are unlikely to be true. So, I made a very crude filter by determining the mean distance to the water level (calculated on all data including those that I think are probably erroneous), which was 2.01m, and removed all data points that deviated from this by more than 1.50m. I chose this threshold just by eyeballing the data and its a pretty generous filter in that it definitely lets through some remaining noise, but I thought thats better that excluding some valid data.

Here is the daily mean water level for the available data bracketed by the daily maximum and minimum in grey. Clearly there are still some values that are most probably errors and they will be affecting the calculated mean values, but you can see the general pattern of peak water level during the core monsoon months which is as expected.

phanka_dailywaterlevelThen I used the 15 minute data to plot the hour of the day when the high and low water occurred. Becasue of limitations in the size of the memory of teh datalogger (which overwrites its data once its full), this covers only the latter part of 2007. I think the plot is kind of interesting as it looks like during the core summer monsoon months of July, August and September that the river level is highest around the middle of the night, whereas outside of these three summer monsoon months the river is highest in the middle of the day.

phanka-flow-timingTo be honest I’m not totally sure how to interpret this. Is this because the monsoon rain comes in the afternoon/evening here and by the time it all comes downstream its late into the night? Or does this tell us something about the efficiency of the glacier drainage system varying between these two seasons? I’d need to analyse the precipitation data at the same time to start exploring this, and I do not have that data to hand just now. Watch this space.

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Sketchfab

Check this out – I can embed sketchfab visuals here on my website!

We made 0.5cm resolution surface models of penitentes on the Tapado Glacier in Chile for our last paper in The Cryopshere.

This is site B on Tapado glacier on the 3rd of January. The are shown above is about 2m x 2m (the corner stakes are 2m apart). For the analysis in the paper this are was trimmed down to 1.5 x 1.5 m.

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Glacier mass balance infographic

Allie Strel is studying cartography and is one of the staff partly responsible for the student mass balance measurements of the Juneau Icefield during JIRP each summer. She has made this infographic of the Juneau icefield mass balance measurement program:

tackling-the-taku-mass-balance-infographic-allie-strel

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East African Glaciers on GlacierHub

Georg Kaser just brought to my attention that our work on Mt Kenya was features on GlacierHub and the Mountain Partnership websites:

East African Glaciers at Risk from “Global Drying”

 

 

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