A new system for monitoring glaciers using optical fibers has appeared. It is more accurate and faster than tracking the movement of glaciers from a satellite.
Researchers explained that seismic monitoring of glaciers is important to improve understanding of their development and risk prediction. Fabian Walter, a professor at the Swiss National Science Foundation, has come up with a new monitoring tool – optical fiber. With their help, you can monitor entire glaciers.
Glaciers are constantly moving, but seismometers are difficult to install in parts of the glacial regions, so their coverage is uneven. In his research, Walter demonstrated that monitoring can be done with optical fibers. They are easier to install and they have a large number of measurement points. Thus, they represent a way to expand seismic monitoring coverage in hard-to-reach areas.
For five days in March 2019, two teams led by Fabian Walter recorded earthquakes with a fiber optic cable laid a few centimeters deep in the snow on the surface of the glacier. Distributed acoustic sounding was used to record the fluctuations of the optical signal (the result of seismic events within the glacier) at regular intervals of several meters along the cable. These records were converted to seismograms.
In the presence of a much larger number of sensors in the same monitoring zone, the obtained data contained more information than the data of seismometers, especially regarding glacial shocks. Moreover, fiber optics provided a better understanding of glacier movement.