Limits...
Mesoscale eddies transport deep-sea sediments.

Zhang Y, Liu Z, Zhao Y, Wang W, Li J, Xu J - Sci Rep (2014)

Bottom Line: We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies.The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons.Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.

ABSTRACT
Mesoscale eddies, which contribute to long-distance water mass transport and biogeochemical budget in the upper ocean, have recently been taken into assessment of the deep-sea hydrodynamic variability. However, how such eddies influence sediment movement in the deepwater environment has not been explored. Here for the first time we observed deep-sea sediment transport processes driven by mesoscale eddies in the northern South China Sea via a full-water column mooring system located at 2100 m water depth. Two southwestward propagating, deep-reaching anticyclonic eddies passed by the study site during January to March 2012 and November 2012 to January 2013, respectively. Our multiple moored instruments recorded simultaneous or lagging enhancement of suspended sediment concentration with full-water column velocity and temperature anomalies. We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies. The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons. Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

No MeSH data available.


Related in: MedlinePlus

Seafloor topography and sea surface level anomaly in the northeastern South China Sea (SCS).(a) Seafloor topography showing the location of the TJ-A-1 mooring system and its vertical structure (left side). The three-dimensional topography map is created from the 30-arc-second resolution global topography/bathymetry grid (STRM30_PLUS)13 using Global Mapper 12. Two RCMs are equipped with probes for turbidity and temperature measurement (see Methods for more details of the mooring system). Potential sediment transport pathways of illite and chlorite derived from Taiwan and smectite originated from Luzon are also displayed14. (b) Map of sea level anomaly (SLA) with surface geostrophic current velocity (shown as black arrows) on 15 February 2012 when an anticyclonic eddy passed by the mooring site (white star). The map is generated through combining SLA and surface geostrophic current velocity data distributed by AVISO (http://www.aviso.oceanobs.com) using Matlab R2010b. Centroidal tracks of three eddies from birth until death, marked every 3 days (circles), are superimposed on the map. Red and blue circles stand for an anticyclonic and a cyclonic eddy born in November 2011, respectively; green circles represent an anticyclonic eddy born in November 2012. The inset figure in the lower part of (b) shows the u (along-slope) and v (cross-slope) coordinates (see Methods for detailed descriptions).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4120309&req=5

f1: Seafloor topography and sea surface level anomaly in the northeastern South China Sea (SCS).(a) Seafloor topography showing the location of the TJ-A-1 mooring system and its vertical structure (left side). The three-dimensional topography map is created from the 30-arc-second resolution global topography/bathymetry grid (STRM30_PLUS)13 using Global Mapper 12. Two RCMs are equipped with probes for turbidity and temperature measurement (see Methods for more details of the mooring system). Potential sediment transport pathways of illite and chlorite derived from Taiwan and smectite originated from Luzon are also displayed14. (b) Map of sea level anomaly (SLA) with surface geostrophic current velocity (shown as black arrows) on 15 February 2012 when an anticyclonic eddy passed by the mooring site (white star). The map is generated through combining SLA and surface geostrophic current velocity data distributed by AVISO (http://www.aviso.oceanobs.com) using Matlab R2010b. Centroidal tracks of three eddies from birth until death, marked every 3 days (circles), are superimposed on the map. Red and blue circles stand for an anticyclonic and a cyclonic eddy born in November 2011, respectively; green circles represent an anticyclonic eddy born in November 2012. The inset figure in the lower part of (b) shows the u (along-slope) and v (cross-slope) coordinates (see Methods for detailed descriptions).

Mentions: As an active and ideal region for generation and propagation of mesoscale eddies, the South China Sea (SCS) has been investigated through both observation and numerical modelling for kinematic mechanism and hydrographic structure of these mesoscale eddies101112. However, how such eddies influence the deep-sea sediment dynamic process has not been explored yet. For this purpose, we deployed a full-water column mooring system (TJ-A-1) equipped with Acoustic Doppler Current Profiler (ADCP), Recording Current Meter (RCM), and sediment trap systems at the lower continental slope with a water depth of 2100 m in the northeastern SCS (Figure 1a). The observed current velocity, temperature, and suspended sediment concentration (SSC) data, spanning nearly two years (from September 2011 to May 2013), reveal two southwestward deepwater sediment transport events that are attributed to the identified surface mesoscale eddy activities. Our study is for the first time to have observed how the upper-ocean hydrodynamic process affects the cross-basin sediment transport in the deepwater environment.


Mesoscale eddies transport deep-sea sediments.

Zhang Y, Liu Z, Zhao Y, Wang W, Li J, Xu J - Sci Rep (2014)

Seafloor topography and sea surface level anomaly in the northeastern South China Sea (SCS).(a) Seafloor topography showing the location of the TJ-A-1 mooring system and its vertical structure (left side). The three-dimensional topography map is created from the 30-arc-second resolution global topography/bathymetry grid (STRM30_PLUS)13 using Global Mapper 12. Two RCMs are equipped with probes for turbidity and temperature measurement (see Methods for more details of the mooring system). Potential sediment transport pathways of illite and chlorite derived from Taiwan and smectite originated from Luzon are also displayed14. (b) Map of sea level anomaly (SLA) with surface geostrophic current velocity (shown as black arrows) on 15 February 2012 when an anticyclonic eddy passed by the mooring site (white star). The map is generated through combining SLA and surface geostrophic current velocity data distributed by AVISO (http://www.aviso.oceanobs.com) using Matlab R2010b. Centroidal tracks of three eddies from birth until death, marked every 3 days (circles), are superimposed on the map. Red and blue circles stand for an anticyclonic and a cyclonic eddy born in November 2011, respectively; green circles represent an anticyclonic eddy born in November 2012. The inset figure in the lower part of (b) shows the u (along-slope) and v (cross-slope) coordinates (see Methods for detailed descriptions).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120309&req=5

f1: Seafloor topography and sea surface level anomaly in the northeastern South China Sea (SCS).(a) Seafloor topography showing the location of the TJ-A-1 mooring system and its vertical structure (left side). The three-dimensional topography map is created from the 30-arc-second resolution global topography/bathymetry grid (STRM30_PLUS)13 using Global Mapper 12. Two RCMs are equipped with probes for turbidity and temperature measurement (see Methods for more details of the mooring system). Potential sediment transport pathways of illite and chlorite derived from Taiwan and smectite originated from Luzon are also displayed14. (b) Map of sea level anomaly (SLA) with surface geostrophic current velocity (shown as black arrows) on 15 February 2012 when an anticyclonic eddy passed by the mooring site (white star). The map is generated through combining SLA and surface geostrophic current velocity data distributed by AVISO (http://www.aviso.oceanobs.com) using Matlab R2010b. Centroidal tracks of three eddies from birth until death, marked every 3 days (circles), are superimposed on the map. Red and blue circles stand for an anticyclonic and a cyclonic eddy born in November 2011, respectively; green circles represent an anticyclonic eddy born in November 2012. The inset figure in the lower part of (b) shows the u (along-slope) and v (cross-slope) coordinates (see Methods for detailed descriptions).
Mentions: As an active and ideal region for generation and propagation of mesoscale eddies, the South China Sea (SCS) has been investigated through both observation and numerical modelling for kinematic mechanism and hydrographic structure of these mesoscale eddies101112. However, how such eddies influence the deep-sea sediment dynamic process has not been explored yet. For this purpose, we deployed a full-water column mooring system (TJ-A-1) equipped with Acoustic Doppler Current Profiler (ADCP), Recording Current Meter (RCM), and sediment trap systems at the lower continental slope with a water depth of 2100 m in the northeastern SCS (Figure 1a). The observed current velocity, temperature, and suspended sediment concentration (SSC) data, spanning nearly two years (from September 2011 to May 2013), reveal two southwestward deepwater sediment transport events that are attributed to the identified surface mesoscale eddy activities. Our study is for the first time to have observed how the upper-ocean hydrodynamic process affects the cross-basin sediment transport in the deepwater environment.

Bottom Line: We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies.The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons.Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.

ABSTRACT
Mesoscale eddies, which contribute to long-distance water mass transport and biogeochemical budget in the upper ocean, have recently been taken into assessment of the deep-sea hydrodynamic variability. However, how such eddies influence sediment movement in the deepwater environment has not been explored. Here for the first time we observed deep-sea sediment transport processes driven by mesoscale eddies in the northern South China Sea via a full-water column mooring system located at 2100 m water depth. Two southwestward propagating, deep-reaching anticyclonic eddies passed by the study site during January to March 2012 and November 2012 to January 2013, respectively. Our multiple moored instruments recorded simultaneous or lagging enhancement of suspended sediment concentration with full-water column velocity and temperature anomalies. We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies. The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons. Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

No MeSH data available.


Related in: MedlinePlus