IGF



Seminarium fizyki litosfery i planetologii

Relation between sea waves activity and wavefield of the ambient noise recorded in northern Poland

dr Simone Lepore, prof. Marek Grad

Instytut Geofizyki, Wydział Fizyki, Uniwersytet Warszawski

 

14 czerwca 2019 09:30, ul. Pasteura 5, sala B4.58

Ambient noise was recorded from July 2013 to September 2016 at the “13 BB star” array located in northern Poland. The array geometry enables to assemble the propagation features of the low‑frequency surface waves constituting the noise wavefield regardless of their azimuth. In this study we apply two techniques to the recorded noise, namely  the power spectral density (PSD) and the frequency‑domain beam‑forming (BF). Analysis of sea wave activity from the forecast model and noise wavefield show that the sources of primary microseisms (PM) are the strong ocean waves hitting the coastlines, while the secondary microseisms (SM) are generated in the open sea. For what concerns the North Indian Ocean, primary and secondary microseisms are clearly visible only in the case of land depressions and tropical cyclones. Referring to Atlantic Ocean, primary and secondary microseisms are clearly visible for all the occurred storms, as they hit the coastlines rather close to the array.

Uwaga! Sala B4.58 jest w nowym budynku Wydziału Fizyki (skrzyżowanie ulic Banacha i Pasteura). Dojście również od ulicy Pasteura. Windą proszę udać się na IV piętro i prawie do końca na południe (w stronę ulicy Banacha), po lewej stronie. Jej zaletą jest, że na kawę/herbatę będziemy mieli tylko 10 metrów.


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