A hard-working field geophysicist

If you want to really get to know your country, or faraway places in the world, I suggest you choose the profession of a field geophysicist. It will take you from forgotten locked backdoor storages to the top of the world. And on the way you will experience plenty of amazing spots. As well as places you never want to visit again.  

I started my career as a field geophysicist around 2010, in Stockholm, Sweden. At that time, as my former colleague said, the field geophysicists in Sweden could fit in a Minivan. Swedish geophysical instruments from ABEM and MALÅ Geoscience, were well-known around the world but just as no-one becomes a prophet in one’s own country, their use was sparse, especially for GPR in Stockholm. I, however, thought I could be of some use to a geotechnical department within a mid-sized consultant company. So, from here I took my first staggering steps on my journey around the world.

At the beginning it was quiet, my expeditions were mainly around Stockholm, to find a utility line or two, prior to more important geotechnical drilling taking place. But slowly my colleagues in geotechnical engineering started to see the benefits of geophysics and my workload increased to also include depth to bedrock measurements. One of my colleagues said “you are my extra pair of eyes, I need you to make a better basis for planning my drillhole locations”. He loved to stay by his desk, check the site by Google Maps and say, “easy access, easy to investigate” and then sent me out to this:  

This is when I learned, I need to be both strong and stubborn–headed. And buy some good orthopedic boots. Regardless of the lousy terrain, I loved, and continue to love, all my meters of GPR investigations. Okay maybe not ALL; not when I…. 

  • … realized I am not going to make it back to the car before sunset. So, always keep an extra battery for your mobile phone in the pocket. Or even better, invest in a head lamp. I have actually also used the screen of a Terrameter SAS 1000 as a flashlight.
  • … found myself in between different groups of hunters and dogs, looking for elks. And me being afraid of bears, so I was wearing a bear-bell. Mmmmm, all elks already long gone and high visibility clothing is good to have also in forests. The hunters were nice, offered coffee and took off for another forest. 
  • … took a short cut, in the middle of nowhere, and got lost. I thought it was easier to walk and find the correct way without my GPR so I left it behind a stone. And lost that too. It took me 4 hours to find the GPR and the way back to the car.
  • … again, was lost, on back-side forest roads, besides more or less abandoned houses, followed by suspicious people (at least in dusk and at distance) realizing no one knew of my whereabouts. And yes, from there onwards I always have a GPS with both SOS and SMS functionality. A life saver. As you are almost always alone and as me, always forgetting to give precise locations to my manager. 
  • … pressed delete instead of upload. And more than 5 km of data was gone. 30 degrees heat, hungry, and thirsty, I turned around and collected the data again. This actually resulted in a software change, the upload option was moved further away from the delete button.
  • … flew far up north in Sweden, stayed overnight, and the next morning realized the investigation spot was way too conductive. So, the planned 8 km of profiles became 100 meters. Lesson learned: always be super clear about GPR limitations.
  • … was chased by a herd of cows. Or what appeared to be cows but was in fact young bulls. From this point and forward, I have avoided doing any measurements accompanied by animals.  

From bedrock investigations the area of applications extended even more. To lakes and rivers and water-power dams. This was nice! I had company, by the captain of the boat, and could just enjoy the nice settings of different lakes around Sweden. Okay, sometimes wet, sometimes a bit risky due to small boat sizes and sometimes in a hurry to carry out all measurements before battery loss. When the GPR antenna was securely sealed with loads of gaffer tape in a waterproof container, this is also when I learned to collect data by time and understand the importance of pace when looking at hyperbolas. In Sweden we have the opportunity to do the same work from ice, but that is of course colder. And you need to walk.

After some time in the geotechnical department, the word spread of this magical non-destructive x-ray imaging device and I started to get missions for the construction, environmental and road/railroad departments. This is when the travelling throughout Sweden started on a larger-scale. My 15-year-old daughter is rather fed up with me, screaming from the driver seat in the car “oh, I have been here with my radar”. The longest trip by car was from Stockholm to the lighthouse of Falsterbo: 647,7 km one way. I started quite early, finished the measurements on the masonry during a long lunch and returned home at witching hour. Then, to travel 300 km to do a half hour field effort felt like a walk in the park. And did you know that… 

  • … it is possible to do GPR investigations from a railway trolley? It is really nice to bike! But make sure you have a traffic warden as company so you can move the trolley before the trains pass.
  • … you can over-come fear of heights by climbing stairs and scaffolding with GPR equipment. One of the scariest places was inside of a water-power plant. Not only due to high scaffolding, and wide gaps, but also due to the fact that if somebody pressed the wrong button, the turbine hall would be water-filled within seconds. 
  • … GPR opens doors to castles and other historical buildings, never ever opened to the public before. It is a perfect tool to use both inside and outside buildings, on roofs, walls and floors. I have had the possibility to visit both the Royal and the Governor Palace in Stockholm as well as mansions around Sweden. 
  • … you also can look for hidden spaces and treasures? I once got the questions to look for Marie Antoinette’s jewels. Imaging done but no luck that time, I only found empty hidden spaces.
  • … GPR will find underground storage tanks? One time a resident complained on heavy headaches, my GPR could point out the spot the construction company had forgotten to decontaminate.
  • … you can investigate huge masonry walls for loose stones? But do not try to use a sky-lift in heavy winds. It was easier to carry out GPR measurements using a home-built lifting device instead.
  • … that even short field efforts can take time? Often you run into one, two, several pensioners. Curious. Time flies, but you gain nice knowledge as well. Sometimes as good as: “Yes, I put that pipe here myself. It should be five meters in that direction”.

For a long time my workplace was Sweden, from Skåne to Lappland. And I was really content. Outdoor work, on my own, with my car packed full of GPR equipment, gaffer tape and tools. And then also the exciting interpretation work, could I solve the problems for the customer? Will they get more information on bedrock, construction, objects, structure, layers….? Or maybe knowledge of something completely different but important? Good friends, former colleagues, and connections, however, wanted different and took me to the Himalayas, as well as to the ice cap of Greenland. This in another story but start of these adventures can be found here. LINK

Today the use of geophysics in Sweden has grown, and so to the number of field geophysicists; maybe we need two ordinary buses to accommodate them now. This makes me happy, really happy. I am back on office duty, still content. With opportunities of small glimpses of the outside world in the form of training, conferences, support and data interpretation from both near and far. And, the best, testing of new equipment, sometimes as far away as the streets outside my garden… 😉

 

Jaana Gustafsson, Applications Specialist, Phd