Characterization of seabed properties from Scholte waves acquired on floating ice on shallow water

Abstract

A B S T R A C TSeismic surveying of the coastal areas in the Arctic is best facilitated during wintertime when the sea ice is land-fast. This eases the logistics of the operation and assures that there is no damage made to the vulnerable tundra. Seismic experiments on floating ice on shallow water performed in a fjord in Svalbard in the Norwegian Arctic show prominent Scholte waves. The dispersion relation of Scholte waves can provide the shear wave velocities of the seabed sediments. Scholte wave data can potentially be obtained when the seismic source and geophone receivers are both placed on top of the floating ice. However, the Scholte wave data become more distinct by using an air gun lowered some metres below the ice. A rock physics model based on a twostep differential effective medium scheme has been tuned to predict seismic properties found for very loose sediments, among these very high P-wave to S-wave velocity ratios. The rock physics model enables us to convert seismic velocities obtained from Scholte wave data to quantitative estimates of the sediment composition.

Laser-Generated Scholte Waves in Floating Microparticles

“…As the microparticles embedded in agarose are surrounded by the water on all sides, the wave identified here is known as a Scholte wave due to its existence on the solid and liquid interface. The theoretical calculation of Scholte wave velocity was performed using the bisection method where the zero point for the dispersive function shown in the equation below was calculated [ 34 ]: where , = , = , r = …”

Review and Future Perspective of Geophysical Methods Applied in Nearshore Site Characterization

“…Caiti et al [12], Park et al [13], Ritzwoller and Levshin [14], Bohlen et al [15], Puech et al [16], Shtivelman [17], Park et al [18], Kaufmann et al [19], Hunter et al [20], Boiero et al [21], Paoletti et al [22], and Long et al [23] used the underwater seismic surface wave method to measure the Swave velocity profiles of seabed sediments. Moreover, Johansen and Ruud [24] used the underwater seismic surface wave method on ice floes to find seabed properties in the arctic circle. Wilken et al [25] used an underwater seismic surface wave method to survey S-wave velocity profile of the seabeds to allocate possible sites for offshore windtower installation, and subsequent dynamic analysis of monopile foundations.…”

“…These interface waves in the vertical direction generally come in two forms, one being Scholte waves, and the other being Leaky Rayleigh waves. Leaky Rayleigh waves occur mainly on the seabed surface when the shear wave velocity of the shallow depth of seabed is greater than the longitudinal velocity of the water [24]. Due to this, in most non-rocky shores, only Scholte waves exist.…”

Integrated Geophysical Analyses of Shallow-Water Seismic Imaging With Scholte Wave Inversion: The Northern Adriatic Sea Case Study

“…These interface waves, propagating along the seafloor, are called Scholte waves and have peculiar characteristics in respect with the body waves, since they have low velocities, low frequencies, and a high degree of polarization (i.e., Rauch, 1986;Zhang et al, 2013). The energy of this type of waves is concentrated at the water-sediments interface and becomes dispersive with depth due to the occurrence of several wave modes because of changes in the sediment properties (i.e., Flores-Mendez et al, 2012;Johansen and Ruud, 2020). Clearly, the occurrence of Scholte waves could represent a real problem in seismic data processing and interpretation because they can completely mask deeper reflections (Zheng et al, 2012).…”

“…Clearly, the occurrence of Scholte waves could represent a real problem in seismic data processing and interpretation because they can completely mask deeper reflections (Zheng et al, 2012). On the other hand, these waves could be very useful for extracting the near-surface velocity and deriving the elastic properties of shallow marine sediments, especially for geotechnical-engineering applications (i.e., van Vossen et al, 2002;Bohlen et al, 2004;Kugler et al, 2005;Kugler et al, 2007;Muyzert, 2007a;Muyzert, 2007b;Carbajal-Romero et al, 2013;Johansen and Ruud, 2020). For example, Nolet and Dorman (1996) proposed to apply the nonlinear waveform fitting to match Scholte waves.…”