Has been monitoring The Man for 10 years

It was in the late summer of 2009 that Atle Gerhardsen of Cautus Geo first climbed Mannen and installed equipment to monitor the unstable mountain. At the time, Cautus Geo developed a laser-based system that measures the distance to a reflector with millimetre accuracy throughout the year.

Since then, there has been much more instrumentation in the mountain area. See overview at the bottom of the text.

Using satellites

In 2010, Cautus Geo established a GNSS network that uses satellite data to provide exact positions in 3D. In total, Cautus Geo has established eight GNSS masts in the mountains. This provides measurements with millimetre precision.

- "The system is robust and reliable. It has provided good and precise data for almost ten years," says Lars Krangnes of Cautus Geo.

The GNSS system is still in operation and is one of the most important measurement systems on Mannen, providing good data throughout the year.

Vesleman since 2014

In 2014, Veslemannen, which has been "most in the spotlight this year, started to move.

- We've also supplied a lot of equipment to monitor the mountain there," says Lars Krangnes of Cautus Geo.

There are a lot of monitoring instruments in the landslide-prone mountain area in Romsdalen. Data is continuously sent to Cautus Web, a web portal developed by Cautus Geo. It analyses data in real time and has an alarm function.

- In the event of movements in the mountain section, text messages and e-mails are sent to those responsible at NVE," says Krangnes.

Automatic notification

The data sent to Cautus Web ranges from movements in the mountains to temperature and precipitation.

- Cautus Web shows what's happening and gives an early warning of what's going to happen. Data is fed in at different intervals and can be customised according to the degree of danger. Various alert criteria have been established in the portal that automatically send alerts for various events in the mountain area.

For Cautus Geo, Mannen is important for several reasons.

Tough conditions

- The area is demanding in terms of establishing year-round equipment and the harsh climatic conditions in which it will operate. There are steep slopes and a lot of loose rocks in the mountains. This places great demands on good planning and safety.

- Climate is another challenge. We use alternative electricity and have limited opportunities for maintenance for large parts of the year. This places great demands on the choice of technical solution.

Provided a lot of knowledge

- "What we've done at Mannen has taught us a lot about the design of robust systems and how we can establish reliable measurement systems. It gives us knowledge that we have taken with us to other projects. There is little doubt that our experience from Mannen will be used when we plan and implement other projects, such as construction sites or environmental monitoring of cultural heritage sites.

- "The man has developed into an important test area for various measurement technologies and systems we are developing. We're talking about a mountain section with a unique combination of an active landslide, varying climatic conditions and a lot of good reference data.

This is the instrumentation on Mannen:

• Two 1D lasers (measures distance)
• Eight GNSS measuring stations (retrieves data from satellites)
• Tension rods, of which there are currently eight in the mountain section
• A geophone system measures tremors (movements in the ground)
• System for measuring sound/noise
• Four tilt sensors measure changes in angles
• Multiple cameras (Cautus Geo delivered the first in 2009)
• Others have delivered measurement systems for weather and precipitation, and
• Two radars are located down in Romsdalen.
• Cautus Web, a web-based portal developed by Cautus Geo. It captures data from all instrumentation and monitoring of the mountain section and continuously analyses the data, presents it visually and sends alerts by SMS and email for changes in the values measured and analysed.
• In addition, a borehole system has been established by other suppliers. Data from that system does not go into Cautus Geo.
• NVE's avalanche experts receive data from Cautus Web and set the hazard level.

Cautus Geo AS is an independent company specialising in the development, establishment and operation of various measurement systems. Our goal is to be a leading and developing player in efficient and secure solutions for monitoring structures, land, water, climate and the environment.