Thursday, 28 June 2012

The sample tour continues into the Highlands......

A well deserved chill out day on Sunday in Akureyri, Iceland's second largest settlement with a population of 16,000, involved hot tubs, swimming, more slide action, and a trip to the cinema to see Prometheus. Although the film is pretty awful it was interesting to see whether the parts of Iceland they filmed in made it into the final cut. Going by John's description of the site they filmed just north of Hekla, it looks as though the gravel tracks are the only thing of Iceland they kept in; the volcanoes and local environment were clearly not impressive enough!

Back on the road on Monday we headed West on Route 1 and then at Vatnsskard headed south down the mountain road towards the Kjölur region. This was my first outing into Iceland's interior and the van didn't disappoint in coping with the gravel roads and washboard ruts. A river crossing to access sites on Tuesday made me thankful we had four wheel drive.

Hot springs all the way

On the way down we stopped at Hveravollir which is a collection of hot springs similar to those we later visited at Geysir. The photos don't really do justice to the colours and smells you get from being up close to them. Being located in the middle of a mountain track means it doesn't suffer from an influx of tourists so it still feels fairly remote.  On the way back on Wednesday we managed a well deserved dip in Hveravollir's outdoor hot tub.

Hot spring at Geysir.

The weather has remained reasonable for the last few days although showers and cooler temperatures are far more regular as you would expect from a mountainous region. The two ice caps of Langjökull and Hofsjökull dominate the skyline as you head further west.

Langjökull ice cap with shield volcano on the right and and table volcano on left.

Ash galore

In terms of sampling, we originally found it difficult to find suitable sites to uncover the ash layers. With it being a far more hostile place there are no farms and associated ditches around and the soil is very thin due to constant high winds and lack of vegetation to consolidate it.  We hit hard permafrost in one sample pit whilst digging down. When we did fine a good site the changes in the profiles have been quite interesting with far more course tephra present particularly in the Hekla 3 layer we have been sampling (click here for reminder of the different layers). This isn't as surprising as we've been sampling much closer to Hekla than last week when we were on the north coast. John's colleague Thor Thordarson joined us on Tuesday and was an excellent guide providing really detailed and interesting explanations for a number of the harder to distinguish tephra/ash layers and material from other eruptions such as those from Katla.

A pit sample from the Kjölur region. You can see the black  ash layer from a Katla eruption mid way up the profile between the Hekla 3 (brown top white bottom) and Hekla 4 (light yellow) layers.

It's not all been sunshine and happy sampling though. The small black flies that inhabit the upland areas have been doing a fine impression of the classic midge swarms you often encounter in Scotland. Although these wee flies don't bite as much, their sheer numbers provide enough annoyance that when combined with Tuesday's mild and still conditions they were definitely pushing a category 5 on the Smidge forecast.

Fly survival suit
We're heading back across to Akureyri tomorrow (Thursday) with the intention of continuing the sampling down the East coast.

Saturday, 23 June 2012

How do we know what past volcanic eruptions were like?

John and I have been on the road for a couple of days now working our way up the north of Iceland passing places such as Hvammstagi and Blondous. We've seen some stunning views and encountered some pretty cool geography along our way including basalt dykes, roche moutanees and massive slope failures. We got to within a few miles of the arctic circle when we camped on the Vatnsnesvgar peninsula on Wednesday night. Its been wall-to-wall sunshine (literally, as it hasn't been dark yet) as the UK seems to be getting the worst of the weather whilst we bask in the high pressure.

Chasing the midnight sun at 66 degrees north.  Photo: Alasdair Monteith, 2012

Anyway, we're well underway with the pit digging in search of the ash layers from a number of Hekla eruptions that I described in a previous post. But how do we know we'll find ash when we dig? What does it look like? and how can we be sure which volcano it is from?

Past research has logged the extent of the Hekla eruptions ash coverage and the depth of the ash deposits in different sites across the whole of Iceland. We're moving around Iceland again measuring the depth of ash from the Hekla eruption but also collecting measured samples at each site to estimate the density of the ash and noting down the characteristics of the ash.

Finding a site

Whilst driving around the roads and tracks we're keeping our eyes out for drainage ditches and streams which have cut down into the ground and revealed the soil on either side. Each pit starts off a bit of mystery as we see if we can find the main layers of from the big Hekla eruptions.  These are numbered H1, H3 and H4 as you get deeper, and are roughly 1000, 3000 and 4000 years old.  There was once a layer called H2, but when closer investigation revealed that it was actually under H3, it had to get a new name.

With good sites you can spot the ash layers (in white in the photo below) from a fair distance away. This works well until you find a site which has been altered significantly by large scale flooding or other processes. The Hekla deposits are noticeable in this northern area of Iceland for their distinct colour; it will becoming much harder to identify them from other ash layers the further south and closer to the volcanic region we go.

Example of a sampling site. How many ash layers do you think you can find in this photo?  Photo: John Stevenson, 2012 
In the photo above  you can see the white ash that we think is Hekla 4 in the fat white layer, this is predominately rhyolite - think of the stuff the rocks in the Lake District at places such as Langdale are made of. The slightly grey marks on the top of it show where the volcano started throwing out ash which was made up more of Andesite and Dacite, ash of slightly different compositions to rhyolite, near the end of the eruption.

We spend a wee bit of time at each site checking out the soil wall before digging away excess grass and covering soil with spades and hopefully defining different layers in the process. With a lot of the sites we know to stop digging down when we hit boulder clay, the material deposited by glaciers at the end of the last ice age approximately 10,000 years ago. From here upwards the ash layers emerge as white, creamy or grey.

The art of sampling!  Photo: John Stevenson, 2012

Once we're happy with a section we measure how thick the layers are and where they sit in relation to the surrounding soil and boulder clay. John gets to work logging the characteristics of the ash layers such as size of the ash grains, the colour, as well as sketching the soil profile in his notebook. Meanwhile, I use a variety of tools all mainly used for wallpapering and DIY at home to carefully extract a small section of each ash layer as uncontaminated from the soil as possible. I then measure the size of the sample and then bag it. Then tidy up the site an on to the next area!

It's been a cool couple of days as we meet various people along the way and experience Iceland's awesome environment and friendly culture. Whilst sampling in a stream on Thursday night, a guy who owned the surrounding farmland came and inquired what we were doing. It turned out he was a Principal of a local school and is subsequently going to teach the kids about the ash under their feet and show them how the volcanoes of the south affect them in the north.

We're off down to Akureyri tomorrow (second largest settlement in Iceland) then we either go cross country to the area around the Hekla volcano or continue around the East coast sampling as we go.

Tuesday, 19 June 2012

First few days in Iceland

After flying over nothing but sea for the past couple of hours the first glimpse of Iceland had me thinking we'd taken a wrong turn over Ireland and ended up on the far side of the moon; brown pitted lava fields surround the approach to the airport at Keflavick. I was met by John at the bus terminal at Reykjavik and after a quick clean of the van we got our priorities sorted and headed to Iceland's premier climbing wall which has a plethora of very hard, crimpy routes with an equally impressive number of young, strong climbers. A visit to the Laugardal swimming pool swimming pools, was just the right antitdote to a days travelling and a bit of climbing. I learn't that 44C is very hot and that I still get a thrill going down water slides.


 The weather has been mild and sunny (11C) in the short time i've been here. I'm writing this first part at 23.30 and its still very bright outside so the whole day/night thing could take a while to get used to. 

12.00AM getting ready for bed in the van outside of Reykjavík University.  Photo: Alasdair Monteith, 2012

The plan

We'll be setting off tomorrow (Wednesday) to start digging pits to collect tephra (that's the rock and ash erupted out of volcanoes) samples in the North of the island, and working our way around the whole of the island over the next couple of weeks.

The blue blobs give a (very) rough idea of where we´ll be heading over the next week or so
The ash that John is particularly interested in mapping and measuring comes from the Hekla 3 and 4 eruptions so called because when you start digging into the ground you come across the deposits from eruption 3 first and eruption 4 second. The Hekla 3 deposits are the result of an eruption that occurred 3,100 years ago and the Hekla 4 eruption from around 4,200 years ago, the later is estimated to have spewed out 5,600,000,000 cubic metres of tephra from an eruption similar in scale to Mount St. Helen's in 1982. As with the recent Icelandic eruptions you can find ash from the Hekla 4 eruption around Scotland.  By working out the amount of ash in a given volume and sticking the data in a few computer models, it should help piece together where the ash would go if such an eruption were to occur again. John has a more in-depth explanation of all of this on his blog, Volcan01010.

Apparently most of the island has pretty good 3G connection, blog posting may turn out to be an effective test of this!

Sunday, 17 June 2012

Iceland T-minus 24 hrs

Just packing the last few things in preparation for the trip out to Iceland tomorrow where I will be helping Dr John Stevenson carry out ash sampling and mapping as part of his post doctoral work. I wrote a more detailed outline of the plan for the next 3-4 weeks here.

The weather forecast for the Monday and the following week looks fairly Scottish: cold, fairly wet and damp with the odd sunny spell!

I'll be updating our progress on blog posts and tweets as we tour around the island in the campervan.

Monday, 11 June 2012

A half term break character building.

I spent last week in the Cairngorms assisting Windermere School with their Gold Duke of Edinburgh expeditions. I met a few of the teams during their practice walk in March and it was good to see them out on the hills putting the skills and knowledge they learnt then into practice. Monday and Tuesday were training days and we looked at emergency procedures, navigation skills, personal and group kit and river crossings whilst surviving the best Scotland could throw at us weather wise; snow showers and persistent rain in June is certainly character building! We were lucky the deep area of low pressure which brought the storms and rain to the south of England and Wales didn't hang about in the NE of Scotland.

Snow and hoared up buttress on Coire an Lochain.
I also managed to sneak in a few Munro's during the week and spotted some great periglacial features.

Ploughing boulder and solifluction lobes on the East side of Brearich

My group was pretty easy to follow with their Sombrero's on.

The groups covered around 80km over four days from the north to south Cairngorms. They needed tenacity, team work, leadership and a range of mountain skills to get them through the expedition. Skills and experiences that I think are best learnt outdoors and which I'm sure will stay with them and help with many of life's challenges!