October 2017 fieldwork

In October Kirk and Phil went for a quick trip to swap out the Rockblock units and reset the base station at Fjalls.

In October we swapped the Rockblocks to v3 and reset the base station’s fixed location.

View from Fjalls base station. The rover can be seen just above and to the left of the antenna.

Breida movement from the first point as detected in October. This shows the system is working well!

We installed a Brinno timelapse camera looking towards the glacier margin.

 

 

Fjallsjokull system deployed

Today we set up two dGPS units to measure the speed of some of Fjallsjökull glacier. We chose an area of ice which is clearly moving forward towards the lake.

Here is the dGPS system setup on Fjallsjokull, with Jane Hart and Frey

The photo above shows a “quadpod” supporting the GPS units – which are an adaptation of those made by Matthew Roberts of the Icelandic met-office. The idea is to be strong enough to cope with winter and cast few shadows (which cause ice to grow). The system is currently measuring its position every 3hrs to an accuracy of about 2cm – using signals from the base station to help it.

the dGPS base station installed on a moraine close to the Fjallsjokull glacier. We used speaker stands burried in rocks to support the GPS antenna (top) and hold its 2.4GHz radio antenna (white stick). Shortly after this photo I accidentally kicked sand into the laptop keyboard – so it was not so easy to use after that!

View of Fjallsjokull with our deployement being almost in the middle of this photo.

Iceberg tracker

This is a GPS tracker we quickly built as a test of tracking icebergs – it uses Satellite (Iridium) short text messages to send its location to us every 12hrs. Inside is a large lithium battery pack. The photo below shows a water test in the sink – just in case it ends up in the sea. We used a unit from YB Tracking. More info later!

GPS satellite tracker we built for a test on a Greenland iceberg

GPS satellite tracker we built for a test on a Greenland iceberg

Summer 2014

digging out a GPS station

In summer 2014 we went to collect the dGPS gear – but found most of it buried in old snow from the winter.

GPR survey of the glacier in 2014

We also did an annual survey of the ice depth with the new ground penetrating radar.

 

 

Sunrise over Skálafellsjökull

We have been analysing the time-lapse image sequences from the river camera. Mostly it recorded at 4-hour intervals, but for a couple of days in September 2012 it took pictures every minute – the sequence is shown here.

At about noon the river rises by a few centimetres. The change is hardly noticeable, but we can measure the level quite accurately with careful image analysis, and we can see it happening by watching the river start flowing over a rock in this video.

A miniature waterfall begins to flow over the edge of a rock

The river rises to flow over a rock

We would like to relate this to what is happening up on the glacier. One factor is when the sun falls on the ice, and we can work this out from a map of the terrain. Here we are using a digital elevation model from the ASTER instrument aboard the Terra satellite. (ASTER GDEM is a product of METI and NASA.) The animation shows sunlit areas on the glacier and surrounding mountains increasing as the sun rises on 25 September 2012.

Step by step animation of sunlight spreading over glacier and mountains

Simulated sunrise, 25 September 2012. Vertical scale exaggerated by factor of 5.

Moraine Camera captures first snow of 2013

This simple camera test used our "snow-cape" linux-based Beaglebone computer and a normal logitech webcam. It connected directly via 16km Wifi to Holmur!

This simple camera test used our “snow-cape” linux-based Beaglebone computer and a normal logitech webcam. It connected directly via 16km Wifi to Holmur! (photo Aug 2014)

We are occasionally getting pictures from the camera set up on the moraine of the glacier.

Moraine without snow

Taken on 05/10/2013, with no snow visible

Moraine with snow

Taken on 07/10/2013, with snow visible