Abstract. Seismic methods used in the study of snow avalanches may be employed to detect and characterize landslides other mass movements, using standard spectrogram/sonogram analysis. For avalanches, spectrogram for a station that is approached by sliding exhibits triangular time/frequency signature due an increase over time higher-frequency constituents. Recognition this characteristic footprint suggests useful metric identifying mass-movement events such as landslides. The 1 June 2005...

This work illustrates the great potential of multichannel seismic reflection data to extract information from finestructure meddies with exceptional lateral resolution (10–15 m). We present images three acquired in Gulf Cadiz (SW Iberian Peninsula), which consist concentric reflectors forming oval shapes that sharply contrast background oceanic structure. The reveal presence different regions within are consistent those observed historical temperature (T) and salinity (S) data. core region,...

Marine seismic data display laterally coherent reflectivity from the water column that is attributed to fine‐scale oceanic layering. The amplitude of different reflections expression acoustic impedance contrasts between neighbouring masses, and therefore maps ocean's vertical sound speed density (i.e., temperature salinity) variations. Here we determine relative contribution each parameter by computing salinity partial derivatives density, using them estimate reflection coefficients a real...

This work explores a method to recover temperature, salinity, and potential density of the ocean using acoustic reflectivity data time space coincident expendable bathythermographs (XBT). The acoustically derived (vertical frequency >10 Hz) XBT-derived <10 impedances are summed in domain form impedance profiles. Temperature (T) salinity (S) then calculated from international thermodynamics equations seawater (GSW TEOS-10) an empirical T-S relation with neural networks; finally (ρ) is T S....

Abstract Part of the kinetic energy that maintains ocean circulation cascades down to small scales until it is dissipated through mixing. While most steps this downward cascade are well understood, an observational gap exists at horizontal 10 3 –10 1 m prevents characterizing a key step in chain: transition from anisotropic internal wave motions isotropic turbulence. Here we show can be covered using high‐resolution multichannel seismic (HR‐MCS) data. Spectral analysis acoustic reflectors...

Abstract Marine seismic reflection technique is used to observe the strong ocean dynamic process of nonlinear internal solitary waves (ISWs or solitons) in near‐surface water. Analysis ISWs problematical because their transient nature and limitations classical physical oceanography methods. This work explores a Markov Chain Monte Carlo (MCMC) approach recover temperature salinity ISW field using reflectivity data situ hydrographic data. The MCMC designed directly sample posterior probability...

Abstract This work demonstrates the feasibility of 2‐D time‐domain, adjoint‐state acoustic full‐waveform inversion (FWI) to retrieve high‐resolution models ocean physical parameters such as sound speed, temperature and salinity. The proposed method is first described then applied prestack multichannel seismic (MCS) data acquired in Gulf Cadiz (SW Iberia) 2007 framework Geophysical Oceanography project. strategy flow includes specifically designed preconditioning for noise reduction, followed...

Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed ( c ), density ρ temperature T and salinity S ) from the weak impedance contrasts associated with ocean's thermohaline fine structure.The seismic inversion approaches proposed so far are based on iterative of multichannel data, while rest parameters , determined in a second step using two equations state local ‐ empirical relationship. In this work, we present an...

Recent works show that multichannel seismic (MCS) systems are able to provide detailed information on the oceans' fine structure. The aim of this paper is analyze whether 1‐D full waveform inversion algorithms suitable recover extremely weak acoustic impedance contrasts associated structure, as well their potential image meso‐scale objects such meddies. We limited our analysis synthetic, noise‐free data, in order identify some methodological issues related approach under idealistic...

Abstract. The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters incoming milder cooler Atlantic water. interaction between these two masses originates set of sub-mesoscale structures complex sequence processes that entail mixing close to thermocline. Here we present high-resolution map diapycnal diffusivity around thermocline depth obtained using acoustic data recorded with multichannel seismic system. reveals patchy thermocline, spots...

Recent work shows that multichannel seismic (MCS) systems provide detailed information on the oceans' finestructure. The aim of this paper is to analyze if high order numerical algorithms are suitable accurately model extremely weak wavefield scattered by finestructures. For purpose, we generate synthetic shot records along a coincident and oceanographic profile acquired across Mediterranean salt lens in Gulf Cadiz. We apply 2D finite‐difference time‐domain propagation model, together with...

Abstract. We present the first application of Stochastic Heterogeneity Mapping based on band-limited von Kármán function to a seismic reflection stack Mediterranean water eddy (meddy), large salt lens water. This process extracts two stochastic parameters directly from reflectivity field data: Hurst number, which ranges 0 1, and correlation length (scale length). Lower numbers represent richer range high wavenumbers correspond broader heterogeneity in events. The number estimate for top...

This work investigates the ability of modelling seismic oceanography experiments by using underwater acoustic propagation equations. Seismic tries to retrieve fine structure ocean water masses processing waves reflected in low-contrast interfaces fronts, eddies, internal or thermohaline intrusions. Since reflectivity such is order 10 ―3 ―10 ―4 , absorption capability numerical boundaries becomes crucial. Complex Frequency Shifted offers a better alternative classical Perfectly Matched Layer...

Abstract Marine multichannel seismic (MCS) data, used to obtain structural reflection images of the earth’s subsurface, can also be in physical oceanography exploration. This method provides vertical and lateral resolutions O (10–100) m, covering existing observational gap oceanic All MCS data so far studies have been acquired using conventional instrumentation originally designed for geological work presents proof concept an alternative system that is better adapted has two goals: 1)...

Abstract. We present the first application of stochastic heterogeneity mapping based on band-limited von Kármán function to a seismic reflection stack Mediterranean water eddy (meddy), large salt lens water. This process extracts two parameters directly from reflectivity field data: Hurst number, which ranges 0 1, and correlation length (scale length). Lower numbers represent richer range scale lengths correspond broader events. The number estimate for top meddy (0.39) compares well with...