The number: 0.000277778 degree

1 Feb 2021

Seismology: A most sophisticated instrument

What can ROMY do?

Science, one of the world’s leading research journals, has referred to the ring laser ROMY (Rotational Motions in Seismology) as “the most sophisticated” instrument of its kind in the world. ROMY makes it possible to measure all components of the Earth’s full rotation vector directly on its surface. “It is the world’s most precise instrument for the measurement of ground rotations,” says Heiner Igel, Professor of Seismology at LMU. Accurate measurements of these parameters are of particular interest to basic researchers. For example, in the study of gravitational waves in the cosmos, highly precise rotation data allows the contribution of background seismic noise to the detected signal to be correctly accounted for.

How precisely does ROMY measure?

ROMY measures fluctuations in the orientation of the Earth’s axis with an accuracy of 0.000277778 degree, i.e. 1 arc-second. The ring laser also takes the rate of precession of the axis of rotation into account. But ROMY‘s greatest advantage is that it works virtually in real time. Data no longer need to be analyzed for hours before the result is known.

Why are the results important?

The high-precision data measured by ROMY are of fundamental significance for geodesy and seismology. The measurements are of great scientific interest for the understanding of the physics of earthquakes and for seismic tomography. “We have already collected very valuable data on earthquakes and ocean-generated seismic waves,” says Igel.