Blue ribbons in the hedge
09.01.2026
Many residents of Randers and Mariagerfjord municipalities will see a blue ribbon placed in their hedge or outside their house. The purpose is to mark where a geophone should be placed.
Before Christmas, we announced that the major survey of the subsoil had begun. The first step was to mark the points where a geophone was to be placed. Out in the countryside, the markings were made with a bamboo stick, and in the towns with a small blue cross on the road. This work began before Christmas and is now continuing. However, due to the weather, the blue cross on the asphalt has been replaced or supplemented by a blue ribbon in a hedge or around a fence post, a lamppost or even a ‘for sale’ sign.
Subsequently, a geophone will be placed at the marked points. In urban areas, the geophone will be equipped with a small note asking that it be allowed to remain in place. We hope that both the blue ribbons, bamboo sticks and geophones will be left in place, as this will be a great help to us and enable us to complete the survey as quickly as possible. The geophones will be collected after 10-15 days.
Geophones are small receiving devices that register and record signals from underground layers caused by vibrations sent into the ground by a vibration truck. The geophones are placed 20 metres apart in lines 160 metres apart, but the trucks’ routes are much more scattered. The trucks drive in east-west lines with 160 to 360 metres between them. They stop and vibrate for 30-60 seconds every 40 metres. As mentioned, the marking of where the geophones are to be placed has begun; in a few days, the laying of the geophones will begin. The trucks will not start driving in the area until week 4.
At www.greenstore.dk, there is a map where you can follow the location of the trucks in each week. The trucks will drive one at a time along carefully planned routes. Danish-speaking Rambøll staff will be on hand or nearby to answer questions from landowners and interested citizens. Rambøll can also be contacted on +45 6036 2540 during daytime hours. No major traffic diversions are planned in connection with the survey.
Greenstore will distribute a small leaflet about the project in the middle of week 3 to the entire area, which covers 520 km2 between Randers in the south and Hobro and Mariager in the north.
