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Data Publisher for Earth & Environmental Science

Stark, Nina; Hanff, Hendrik; Svenson, C; Ernstsen, Verner Brandbyge; Lefebvre, Alice; Winter, Christian; Kopf, Achim J (2010): Penetration velocity and deceleration of penetrometer stations N1 to N97 during cruise Senckenberg_11_2008. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.745600 (unpublished dataset), Supplement to: Stark, N et al. (2011): Coupled penetrometer, MBES and ADCP assessments of tidal variations in surface sediment layer characteristics along active subaqueous dunes, Danish Wadden Sea. Geo-Marine Letters, 31(4), 249-258, https://doi.org/10.1007/s00367-011-0230-6

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Abstract:
In-situ geotechnical measurements of surface sediments were carried out along large subaqueous dunes in the Knudedyb tidal inlet channel in the Danish Wadden Sea using a small free-falling penetrometer. Vertical profiles showed a typical stratification pattern with a resolution of ~1 cm depicting a thin surface layer of low sediment strength and a stiffer substratum below (quasi-static bearing capacity equivalent: 1–3 kPa in the top layer, 20–140 kPa in the underlying sediment; thickness of the top layer ca. 5–8 cm). Observed variations in the thickness and strength of the surface layer during a tidal cycle were compared to mean current velocities (measured using an acoustic Doppler current profiler, ADCP), high-resolution bathymetry (based on multibeam echo sounding, MBES) and qualitative estimates of suspended sediment distributions in the water column (estimated from ADCP backscatter intensity). The results revealed an ebb dominance in sediment remobilization, and a general accretion of the bed towards low water. A loose top layer occurred throughout the tidal cycle, likely influenced by bedload transport and small events of suspended sediment resettlement (thickness: 6 +-2 cm). Furthermore, this layer showed a significant increase in thickness (e.g. from 8 cm to 16 cm) related to periods of overall deposition. These findings imply that dynamic penetrometers can conveniently serve to (1) quantify potentially mobile sediments by determining the thickness of a loose sediment surface layer, (2) unravel sediment strength development in potentially mobile sediments and (3) identify sediment accumulation. Such data are an important complement and add a new geotechnical perspective during investigations of sediment remobilization processes in highly dynamic coastal environments.
Related to:
Stark, Nina (2011): Geotechnical Investigation of Sediment Remobilization Processes using Dynamic Penetrometers. PhD Thesis, Elektronische Dissertationen an der Staats- und Universitätsbibliothek Bremen, Germany, urn:nbn:de:gbv:46-00101886-19
Coverage:
Median Latitude: 55.314049 * Median Longitude: 8.505004 * South-bound Latitude: 55.313246 * West-bound Longitude: 8.500141 * North-bound Latitude: 55.314958 * East-bound Longitude: 8.510245
Date/Time Start: 2008-11-06T07:43:00 * Date/Time End: 2009-11-06T19:27:00
Minimum Elevation: -16.0 m * Maximum Elevation: -8.0 m
Event(s):
Senckenberg_11_2008_N1 (N1) * Latitude: 55.313447 * Longitude: 8.501182 * Date/Time: 2008-11-06T07:43:00 * Elevation: -14.0 m * Location: Knudedyb, Denmark * Campaign: Senckenberg_11_2008 * Basis: Senckenberg * Method/Device: NIMROD (NIM) * Comment: accelerated ebb
Senckenberg_11_2008_N10 (N10) * Latitude: 55.314654 * Longitude: 8.508801 * Date/Time: 2008-11-06T09:06:00 * Elevation: -14.0 m * Location: Knudedyb, Denmark * Campaign: Senckenberg_11_2008 * Basis: Senckenberg * Method/Device: NIMROD (NIM) * Comment: accelerated ebb
Senckenberg_11_2008_N11 (N11) * Latitude: 55.313981 * Longitude: 8.504835 * Date/Time: 2008-11-06T09:11:00 * Elevation: -12.0 m * Location: Knudedyb, Denmark * Campaign: Senckenberg_11_2008 * Basis: Senckenberg * Method/Device: NIMROD (NIM) * Comment: accelerated ebb
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1Event labelEvent
2Penetration depthPenetr depthmStark, NinaFree fall penetrometer, NIMROD
3Penetration velocityPenetr velm/sStark, NinaFree fall penetrometer, NIMROD
4DecelerationDecelgStark, NinaFree fall penetrometer, NIMROD
Size:
13134 data points

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