Analysis On The Characteristics And Source Location Of Microseisms During Hurricane Movement In The Pacific Ocean

The Pacific is the waters of intense hurricane activity,hurricanes cause thousands of casualties every year.In order to predict the path,location and grade of hurricanes,wave field simulation and seismology are combined to study the characteristics of Microseisms during hurricane movement.Data from 34 land stations in Europe,North America,South America,Africa and Australia,13 Ocean Bottom Seismometer(OBS)stations in the Northwest and Central Pacific and 8 Hydrophone stations in the South Pacific were downloaded from IRIS website.Using FK analysis and polarization analysis combined with wave numerical simulation,the Microseisms during hurricane movement in The Pacific region in February and March 2010 and August and September 2006 was analyzed,it is concluded that the Hydrophone stations,OBS stations and land stations recorded Microseisms signal differences and Estimation of the source region of the Microseisms induced by hurricanes.The primary Microseisms(with a period of 10-20s)and the second Microseisms(with a period of 2-10s)recorded at the land stations,Hydrophone stations and OBS stations show great differences.In terms of the primary Microseisms,Hydrophone stations is mainly affected by sea water oscillation,while OBS stations is mainly affected by ocean floor turbulence,while land stations are relatively stable.As a result,Hydrophone and OBS stations are obviously inferior to land stations in recording the primary Microseisms signal,and there are also differences between land stations.The recording effect of horizontal component of island stations on the primary Microseisms is obviously inferior to that of inland stations.In the frequency range of the second Microseisms,the acceleration power spectrum recorded by OBS and Hydrophone stations appears multiple peaks,while the results of land stations are relatively smooth.It is possible that OBS and Hydrophone are close to the second Microseisms signal source,so they can record the seismic wave energy transformed by the wave pressure changes of different wavelengths in the ocean bottom crust.The overall energy level of hydrophone station is higher than that of OBS station,and OBS station is higher than land station.The signals recorded by land stations are mainly Rayleigh wave motion and linear motion in horizontal or vertical plane.However,OBS and Hydrophone stations only show linear motion characteristics of high-frequency signals from individual stations in horizontal and vertical planes.The F-K analysis and polarization analysis were used to analyze the data of 8stations in YL network and 4 stations in AU network in the South Pacific region during Hurricane RENE with maximum central wind speed of 100km/h from February 9 to 19,2010 and Hurricane TOMAS with maximum central wind speed of 115km/h from March 10 to 17,2010,combined with hurricane path,wind speed,surge,period and other information,The correlation between Microseisms,cyclone and ocean wave and the difference between different research methods are obtained The analysis showed that at lower cyclone levels(with weaker wind speeds),the cyclone was unable to drag the ocean and thus generate the Microseisms signal associated with the cyclone.When the cyclone reaches typhoon level,due to the high wind speed,the surge area with high waves moves with the cyclone and produces Microseisms signals which can be observed by seismometer.The f-K method based on the multi-stations method is more accurate than the polarization method based on the single-station method for the estimation of signal direction parameters,mainly because the polarization method requires higher signal-to-noise ratio of data.The polarization analysis results obtained by land stations are better than those obtained by hydrophone and OBS stations,which may be due to the fact that hydrophone and OBS arrays are located in the ocean and are easily affected by ocean turbulence,the land stations are more stable and receive less noise energy.Through the analysis of Microseisms characteristics during hurricane hurricane movement caused strong surge of change,at the same time lead to the increase of Microseisms energy,Microseisms energy of hurricane inspired azimuth estimation will help us to predict the wave wave height,direction,etc,in order to reduce hurricane excitation waves caused casualties and economic losses.