He measured it on the Swiss Matterhorn - and thus also proved it for our Bavarian mountains: the Alps sway.
For the Technical University of Munich, the scientist Samuel Weber investigated how seemingly rigid mountain peaks move back and forth.
Munich / Davos
- The two dozen audio files on Samuel Weber's website sound a bit like the mysterious noises of whales underwater, some even remotely resemble the heartbeat of an unborn child.
In fact, an almost 4,500 meter high mountain range knocks and pulsates: the Matterhorn.
Together with an international research team, Weber made the vibration of the mountain audible to the human ear.
His 3D simulation shows the mountain peak from two perspectives, every two seconds the rock masses rock back and forth like a jelly.
The fact is: every geometric body vibrates.
"We only suppress this physical law in individual cases, for example with jukeboxes," says Weber, who carried out the study after completing his doctorate as part of a scholarship at the Technical University of Munich (TUM).
“Everything has a natural frequency.
We don't feel it, we don't see it - but it is there. ”So mountains swing like bridges or skyscrapers.
The oscillation is stimulated by seismic waves in the earth, mainly generated by the tides, ocean surf, earthquake or wind.
TU Munich: research excursion to the Matterhorn
Together with several research colleagues, Samuel Weber climbed the 4,478 meter high landmark of the Valais Alps for the study, the experts installed several seismometers there.
"I've been doing high-alpine research for ten years," says Weber about his unusual workplace.
“So I know the altitude a little.” The highly sensitive devices registered the vibrations of the ground and recorded them.
The scientists set up a measuring station directly at the summit of the Matterhorn, one at an emergency shelter on the northeast ridge and a third as a reference at the foot of the mountain.
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Samuel Weber, researcher at the Technical University of Munich.
© private
From the data, the researchers concluded: the Matterhorn oscillates precisely with a frequency of 0.42 Hertz from north to south and with a similar frequency from east to west.
On the summit, Samuel Weber measured a vibration 14 times higher than at the foot of the mountain.
The reason: The mountain top can move much more freely than the fixed foot, like the crown of a tree in a storm.
Samuel Weber: "The Matterhorn swings better than the Benediktenwand"
Can you also imagine the Bavarian Alps - to put it exaggerated - like a rocking group of stones?
Not quite.
On the one hand, the measured vibrations of a few nanometers to micrometers are extremely low and cannot be felt by humans.
And also: "The vibration depends on the material properties and the geometry of the mountain," says Weber.
Small mountains vibrate at a higher frequency, massive mountains are much more stable than solitary ones: “The Matterhorn was ideal for our measurements.
It stands free, its shape is reminiscent of a pyramid. ”This is another reason why it swings better than the Benediktenwand, for example, he explains.
Does climate change affect the vibrations?
"Indirectly yes.
Because if the properties of the subsurface change and it is no longer frozen, for example, the vibration also changes. "
Samuel Weber now works at the Swiss Institute for Snow and Avalanche Research in Davos.
Here he is already planning another study in the high mountains with a research group: The experts want to investigate the circumstances under which instabilities and possibly dangerous landslides and rock falls can occur in the Alps.
