Pyyhkäisometria

Pyyhkäisometria is a Finnish term that translates to "sweep metry" or "scanning metry" and refers to a method of measuring the frequency of seismic waves. It is particularly relevant in the field of seismology and earthquake monitoring. The technique involves analyzing seismic data recorded by seismometers to determine the dominant frequencies present in the ground motion during an earthquake or other seismic event.

This measurement is crucial for understanding the characteristics of seismic waves, such as their amplitude and how they propagate through the Earth's layers. By identifying the dominant frequencies, seismologists can differentiate between various types of seismic waves (e.g., P-waves, S-waves, surface waves) and gain insights into the source mechanism of an earthquake, the geological structure of the region, and potential hazards.

Pyyhkäisometria often involves signal processing techniques, such as Fourier analysis, to decompose complex seismic signals into their constituent frequencies. The "sweep" aspect refers to the scanning or examination of a range of frequencies to find the ones that are most prominent. This information can then be used for earthquake location, magnitude estimation, and the study of Earth's internal structure. The term highlights a specific approach to frequency analysis in the context of seismic measurements.