Polar Podcasts

12: Niels Henriksen – Mapping remote, uninhabited eastern North Greenland

September 15, 2020 Julie Hollis Season 1 Episode 12
Polar Podcasts
12: Niels Henriksen – Mapping remote, uninhabited eastern North Greenland
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Polar Podcasts
12: Niels Henriksen – Mapping remote, uninhabited eastern North Greenland
Sep 15, 2020 Season 1 Episode 12
Julie Hollis

In this episode, we hear more from Niels Henriksen, emeritus senior scientist at the Geological Survey of Denmark and Greenland, about geological mapping in the most inaccessible part of Greenland – north Greenland – in the mid to late 1970s.

Show Notes Transcript

In this episode, we hear more from Niels Henriksen, emeritus senior scientist at the Geological Survey of Denmark and Greenland, about geological mapping in the most inaccessible part of Greenland – north Greenland – in the mid to late 1970s.

Transcript

12: Niels Henriksen – Mapping remote, uninhabited eastern North Greenland

Based on interviews held on September 26–27, 2019 in Copenhagen, Denmark

Note: Polar Podcasts are designed to be heard. If you are able, please listen to the audio, which includes emotion and emphasis that is not evident in the transcript.

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Niels 0:01

Topographic maps, which were available at that time were made by the American airforce. They were mainly done during the second world war and a little afterwards. But they hadn’t got the necessary ground control, which means that the printed maps they issued were with very big differences in actual position up to fifty kilometres. So that was absolutely impossible for us to work with.

Julie 0:25

Welcome to Polar Podcasts, where you’ll hear stories from geologists who’ve spent their careers, their lives, exploring and studying the remarkable and remote geology of Greenland. Why did they become fascinated with Greenland? What were the problems and the discoveries that drove them? And what was it like working in these remote places, where few people venture, even now? I’m Julie Hollis.

In this episode, we hear more from Niels Henriksen, emeritus senior scientist at the Geological Survey of Denmark and Greenland, about geological mapping in the most inaccessible part of Greenland – North Greenland – in the mid to late 1970s.

Niels 1:09

We had no information about North Greenland. So we had to start, mapping in scale one to a hundred thousand in fieldwork. And with the aim of producing one to five hundred thousand maps from North Greenland. North Greenland is huge. It’s east west is, is about eleven hundred kilometres and north south it’s about two hundred kilometres. Just like in Northeast Greenland, you have to realize that it was an area where you had absolutely no infrastructure. You had to organize everything yourself. And the geology of North Greenland is completely different from everything else GGU had worked with previously. So we have to reorganize ourself both logistically and geologically again.

And again, I was fortunate enough to be asked to start this and first of all reorganize, come up with a plan of how to work there. This started with me as a metamorphic petrologist who had practical experience in basement geology.

Julie 2:09

That is, the igneous and metamorphic rocks.

Niels 2:12

It started with that I was working together with a geologist we had employed in GEUS, GGU at that time preparing ourself for working with  sediments of lower Paleozoic age.

Julie 2:25

That is sedimentary rocks formed between about 540 and 420 million years ago.

Niels 2:32

This geologist, John Peel who was with us for many years became Professor in Uppsala where he has been for many years, he had his first field season in 1975. At that time he was completely inexperienced in Greenland geology. He was also inexperienced in living in a tent under field conditions. So he and I and two assistants, worked together there. We took a season together, simply to learn how to work with sedimentary units. And for him to simply to learn a bit from me about what fieldwork was like and how it was to work with, poor maps. Poor maps, yeah. So that was the season 1975.

We spent a season there in the area called Washington Land, which we flew in to Thule Airbase. We had a Canadian Twin Otter, who flew us two hundred kilometres to the north into Washington Land. There we stayed for the full season. We had lots of problems beginning because the Twin Otter sank in and it took us a full 24 hours to dig it out. 

I learned a lot about measuring sections up, together with John Peel. And we sat for hours, hammering small stones to find fossils. And we worked with, with units were er, Cambrian, Ordovician and er, some up into the lower part of the Silurian.

Julie 3:56

Again, that is sedimentary rocks formed between about 540 and 420 million years ago.

Niels 4:03

And I learned about measuring sections. I made a detailed list of all the sections we made. And John Peel was preparing himself for taking over the leadership of working with all the paleontological and all the stratigraphical work we had to work with in North Greenland later on. 

Julie 4:22

That is working with fossils and with understanding the relative layering of the sedimentary rocks and their relationships in geological time.

Niels 4:31

That was 1975, where we did mapping, not a lot because we had no helicopters. We had to walk around. But we got a lot of primary information for that season. And then we got an impression of how to organize the work in North Greenland.

John Peel continued to work in the region in 1976. And I shifted in the season 1977 to work in the easternmost part of North Greenland. There I simply flew around together with the military Sirius people. They were coming around putting out small depots for their work, where they had their sledge patrol areas and routes. They had to get provisions out in the small huts. I got the opportunity to go around with them. So I got an impression of the area and how we could work with that in a geological sense. I also stayed a period there with the archaeologist Eigil Knuth, who was a well known Danish explorer, one of the old hands. He nearly completely alone did work with archaeological problems. Studying movements of Eskimoes from western part of Canada into the northern part of North Greenland, down along the east coast. I spent time with him. Yeah. After this first reconnaissance season for myself in 77 and John Peel’s work, which continued from 1975, we were able simply to come up with a evaluation how we could tackle the geological mapping of the area.

We had to do, first of all, topographical mapping, which was done here in GGU as photogrammetric work in close coordination with er, Geodetical Institute people. They were cooperating with us and were measuring all the ground control points, which was necessary for doing the aerial photogrammatical topographical mapping. And after that, we simply made an evaluation of how much time we needed and what kind of geologists we should have. And then John Peel, who got lots of contacts got a group of paleontologists and stratigraphers who was working in the area.

We had about the same size of organization as we had previously, which meant that we had about ten, twelve, fifteen, two man groups out every summer. Summers there are about one and a half months. Logistically we did it the same way as I’ve talked about just before. We came in with the whole group, with the C130, the big military aircraft. It could take a payload of about ten tonnes in to Station Nord. And then we flew in with all equipment, all personnel, fuel. Fuel was flown in two months earlier than when we started our own field work if there was frozen ground, so it was hard enough to have the C130 landing there. It can’t be done when you have normal summer temperatures, which is about freezing point because then the ground is becoming soft.

Therefore we had to send out ground personnel. A few of our equipment people, who were staying there in the early to middle part of May. We flew in all the fuel at that time, many trips from Thule with C130 load. So we used more than a hundred thousand litres of fuel. We flew in about ten times from Thule, landing on this natural landing strip at a place called Kap Moltke. We had all the fuel stored in bladder tanks, rubber tanks which simply lay on the ground. When we had prepared fuel for the working season, then the geologists and our support crew, which was helicopters and Twin Otter, came in late June, early July. By that time, from year to year, varying a lot how much snow you had. In some years, we had very little snow and other years we were completely drowned in snow in the beginning. So it’s difficult to say beforehand when is the best time to start. But we had to start anyway in, say early part of July. Then we could stay in the area until about the twentieth to twenty-fifth of August. At that time, the general day temperature went below freezing point then every time you had a little precipitation, it stayed there as snow and then you can’t see what you want to see.  Then you had to go home.  So we had in general something like six to seven weeks of fieldwork.

At that time the helicopters came in with the C130s also. It was one of the newer type, with the lifting capacity about four hundred to five hundred kilos. And with average flying almost two hundred kilometres an hour. So it was very efficient. //  Jet Rangers was the type. Later on came more modern times. But anyway, that was a big difference from where we started with the piston engines early helicopters.

And then you had the Twin Otter. The Twin Otter was used to place out depots, flying around with small geologist groups, putting out fuel depots and other depots for the field people. And then we used it a lot for taking photographs, aerial photographs. They flew along the big fjords and all along the valleys, so we had fantastic coverage of oblique photos taken from the Twin Otter, our photographer, Jakob Lautrup, and I did a lot of the work simply planned the flying. We had the Twin Otter for ourselves. We would organize this as it suited us. You have to do it only when you have possibilities to fly without having shadows or clouds or whatever. So some areas you have to fly in the night time and some in the day time. But we could easily organize that because you have twenty four hours daylight. First in, in middle August the sun starts to go below the horizon. So we had a good possibility to do a lot of observations from the photos, from the flights, and from the helicopters. So we have a fantastic amount of photos from the whole region.

When we started in North Greenland we, from the very beginning realized that it was necessary for us to establish our own topographic base for the work. The topographic maps, which were available at that time were made by the American air force. And they were mainly done during the Second World War and a little afterwards. But at the time when they compiled their maps from photos, they were in a situation where they hadn’t got the necessary ground control, which means that the published maps, printed maps they issued at that time were with very big differences in actual position, up to fifty kilometres of displacement. So that was absolutely impossible for us to work with, especially if you, you had to do it photogrammetrically as we wanted.

Therefore it was from the beginning decided that we had to do the topographic mapping ourselves, at our photo lab in GGU. The Geodetical Institute didn’t have capacity to do it, so they delivered all the ground control points for us. That was at an early stage GPS measurements. They flew around one season and did all the observations which were necessary for them, making ground control points with the difference (distances) of about fifty kilometres. And all the ground control in between there was made by aerial triangulation, which could be done in the lab. So when we worked there the first two years, we more or less had a full time man occupied with doing topographical maps.

At the same time, it was combined with the geologists who worked there, they were in the instrument when they have done the topography, they had time doing whatever they could with geological interpretation from the photogrammetrical instruments. This was very fortunate because people with a field geological experience could sit and do interpretation in the instrument and the same time we had general work done by one of the geologists, who was, employed by GGU as full time photogrammetrical geologist working as a photogeologist. In preparation for our work, he did a full geological interpretation of the whole area so the geologists working in the field were simply given a photogrammetrical interpretation of the geology before they went into the field. That made it very much easier because er, the geologist mainly had to concentrate on establishing the stratigraphy.

Julie 13:19

I’m Julie Hollis and you’ve been listening to Polar Podcasts.

Julie 13:30

In the next episode, we hear more from Emeritus professor Kent Brooks about very close call in a helicopter accident while flying in East Greenland in the 1970s.