Qunshu Tang

Zhejiang University · Ocean College

Recently the novel seismic oceanography method has been reported to be an effective way to study the energetic internal solitary waves (ISWs) in the northern South China Sea. An optimized seismic-oceanographic cruise was carried out to observe such near-surface ISWs on Dongsha Plateau in July 2014. Several soliton trains rather than single solitons...

In this work, a secondary nonlinear internal wave (NIW) on the continental shelf of the northern South China Sea is investigated using high-resolution seismic imaging and joint inversion of water structure properties combined with in situ hydrographic observations. It is an extraordinary wave combination with two mode-2 NIWs and one elevated NIW oc...

Many physical phenomena in the ocean involve interactions between water masses of different temperatures and salinities at boundaries. Of particular interest is the characterisation of finescale structure at the marginal interaction zones of these boundaries, where the structure is either destroyed by mixing or formed by stratification. Using high-...

Mesoscale eddies are ubiquitous in the global ocean and can be captured by marine multichannel seismic surveys. In this study, a short‐lived anticyclonic eddy is characterized along the seismic line STEEP11 acquired on 30 September 2008 in northern Gulf of Alaska. Fine‐scale eddy stratification with alternative strong striae and weak layers is rega...

The Mariana Ridge is one of the prominent mixing hotspots of the open ocean. The high-resolution underway marine seismic reflection technique provides an improved understanding of the spatio-temporal continuous map of ocean turbulent mixing. Using this novel technique, this study quantifies the diapycnal diffusivity of the sub-thermocline (300–1,20...

South Chinea Sea shear velocity model

In situ observations under typhoon conditions are sparse and limited. Distributed acoustic sensing (DAS) is an emerging technology that uses submarine optical-fiber (OF) cables to monitor the sea state. Here, we present DAS-based ocean current observations when a super typhoon passed overhead. The microseismic noise induced by ocean surface gravity...

The deep ocean to the east and south of Taiwan Island‒including the Okinawa Trough, Ryukyu Arc, Philippine Sea, Luzon Strait, and the northeast South China Sea‒is one of the most prominent mixing hotspots of the global ocean. The high‐resolution seismic reflection technique can provide detailed views of the water's finestructure and near‐transient...

Ocean submesoscale dynamics are thought to play a key role in both the climate system and ocean productivity, however, subsurface observations at these scales remain rare. Seismic oceanography, an established acoustic imaging method, provides a unique tool for capturing oceanic structure throughout the water column with spatial resolutions of tens...

Internal solitary waves (ISWs) are investigated offshore of Guangdong in the northern South China Sea (SCS) using high-frequency acoustic backscatter data of 100 kHz acquired in July 2020. Simultaneous XBT profiles and satellite images are incorporated to understand their propagation, evolution, and dissipation processes in shallow water at depths...

The northern margin of the South China Sea (SCS) is often regarded as a magma-poor passive continental margin. Magmatic activities occurred after the cessation of seafloor spreading were founded mainly over the Continent-Ocean Transition (COT) zone. Intrusive rocks are observed in the Luzon–Ryukyu Transform Plate Boundary (LRTPB) dividing Southwest...

Seismic imaging of the ocean water column in the Gulf of Alaska. Observation of the structure of an eddy (upper panel) from the seismic line location shown in the lower panel.

Southeast Asia, located in the southeastern part of the Eurasian Plate, is surrounded by tectonically active margins, exhibiting intense seismicity and volcanism, contains complex geological units with a perplexing evolution history. Because tectonic evolution is closely related to the deep thermal structure, an accurate estimation of the lithosphe...

Marine seismic reflection technique is used to observe the strong ocean dynamic process of nonlinear internal solitary waves (ISWs or solitons) in the near-surface water. Analysis of ISWs is problematical because of their transient nature and limitations of classical physical oceanography methods. This work explores a Markov Chain Monte Carlo (MCMC...

Flow separation can occur when a stratified flow passes over an obstacle. Previous studies concerning flow separation are mostly observed in the shallow water regions, e.g., fjord, driven by tidal flows. In this study, a novel view of flow separations of the intermediate water over the Hengchun Ridge and Ryukyu Arc off Taiwan is firstly reported us...

Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of...

Recent works show that the seismic oceanography technique allows us to relate water column seismic reflections to oceanic finescale structures. In this study, finescale structures of a surface anticyclonic eddy have been unveiled by reprocessing two seismic transects acquired in the northern Gulf of Alaska using an 8-km hydrophone streamer and 6600...

A legacy seismic transect acquired on 30 and 31 May 2009 in the southern South China Sea (SCS) was reprocessed to reveal the thermohaline structure of the water column. In the study region, a mesoscale subsurface lens with extraordinary features was detected at 113.5° E, 11.5° N. It is centred at 450 m depth, occupies both the subsurface and interm...

We present a 3D S-velocity model for the crust and upper mantle of the South China Sea and the surrounding regions, constrained from the analysis of over 12,000 of fundamental Rayleigh wave dispersion curves between 10 s and 150 s periods. The lateral resolution was found to vary from 2° to 4° with the increasing period over the study region. A rob...

A legacy seismic transect acquired on 30 and 31 May 2009 in the southern South China Sea (SCS) was reprocessed to reveal the thermohaline structure of the water column. In the study region, a mesoscale subsurface lens with extraordinary features was detected at (113.5° E, 11.5° N). It is centered at 45 m depth, occupies both the subsurface and inte...

A legacy seismic section across the Luzon Strait was reprocessed using the pre-stack depth migration method to reveal thermohaline structures in the water column. Distinct finescale and mesoscale features can be seen from the seismic image. Vertically, reflective patterns are associated with three water layers: upper layer, intermediate layer, and...

In this paper, a velocity model of the Southern Depression of the Tainan Basin is obtained along with its migrated image from an iterative pre-stack depth migration approach. The Cenozoic strata are uniformly layered with velocities varying from similar to 1.8 to similar to 3.6 km s(-1) However, the general velocity is slightly lower in the NW segm...

We have used Rayleigh wave dispersion analysis and inversion to produce a high resolution S-wave velocity imaging profile of the crust and uppermost mantle structure beneath the northeastern boundary regions of the North China Craton (NCC). Using waveform data from 45 broadband NCISP stations, Rayleigh wave phase velocities were measured at periods...

Eastern China, located at the east margin of the Eurasia plate, is an ideal place to study the deformation pattern of upper mantle beneath continental margin. We investigated the upper mantle anisotropy beneath eastern China by applying teleseismic shear wave splitting measurements. We examined shear wave splitting measurements at 33 permanent stat...