Journal of Archaeological Science 66 (2016) 1e6
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Journal of Archaeological Science
journal homepage: http://www.elsevier.com/locate/jas
Focus
Detection of shipwrecks in ocean colour satellite imagery
M. Baeye a, *, R. Quinn b, S. Deleu c, M. Fettweis a
a
Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environment, Belgium
School of Environmental Sciences, Ulster University, Northern Ireland, United Kingdom
c
Flemish Hydrography, Coastal Division, Agency for Maritime and Coastal Services, Flemish Ministry of Mobility and Public Works, Belgium
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 1 July 2015
Received in revised form
13 November 2015
Accepted 14 November 2015
Available online xxx
Waterborne swath acoustic and airborne laser systems are the main methods used to detect and
investigate fully submerged shipwreck sites. In the nearshore, waterborne techniques are compromised
as search tools as their effective swath is a function of water depth, necessitating very close survey line
spacing in shallow water, increasing cost accordingly. Additionally, in turbid coastal waters bathymetric
LiDAR is ineffective as it relies on clear non-turbid water. Therefore, the nearshore turbid zone represents
a challenging area for archaeologists in the search for fully submerged archaeological sites. In this study,
we describe a new methodology to detect the presence of submerged shipwrecks using ocean colour
satellite imagery in turbid waters. We demonstrate that wrecks generate Suspended Particulate Matter
(SPM) concentration signals that can be detected by high-resolution ocean colour satellite data such as
Landsat-8. Surface SPM plumes extend downstream for up to 4 km from wrecks, with measured concentrations ranging between 15 and 95 mg/l. The overall ratio between the plume and background SPM
concentrations is about 1.4. During slack tidal phases sediments in suspension settle to create fluffy mud
deposits near the seabed. Scour pits developed around wrecks act as sinks where fine-grained suspended
material is preferentially deposited at slacks. The scour pits subsequently act as sources for suspended
material when the bottom current increases after slacks. SPM plumes develop immediately before
maximum ebb or flood current is reached, during maximum current and immediately after. Particulate
matter is suspended in sufficient concentrations to be detected in ocean colour data. The ability to detect
submerged shipwrecks from satellite remote sensors is of benefit to archaeological scientists and
resource managers interesting in locating wrecks and investigating processes driving their evolution.
© 2015 Elsevier Ltd. All rights reserved.
Keywords:
Landsat-8
Suspended sediments
Shipwreck detection
Bathymetry
Scour pits
1. Introduction
Locating fully submerged shipwrecks on the seabed is time
consuming and expensive, made more difficult in the nearshore by
navigation hazards, shallow depths and limited water clarity. The
most common techniques used for locating and investigating underwater archaeological sites on a regional scale are waterborne
swath acoustic techniques such as side-scan sonar (Quinn et al.,
2005) and multibeam echosounder (Plets et al., 2011), and
airborne techniques such as bathymetric LiDAR (Shih et al., 2014).
In the nearshore waterborne techniques are compromised as
search tools because their effective swath is a function of water
depth, necessitating very close survey line spacing in shallow water,
increasing cost accordingly. Furthermore, in turbid coastal waters,
* Corresponding author.
E-mail address: matthias.baeye@naturalsciences.be (M. Baeye).
http://dx.doi.org/10.1016/j.jas.2015.11.006
0305-4403/© 2015 Elsevier Ltd. All rights reserved.
bathymetric LiDAR is ineffective as it relies on clear (non-turbid)
water (Wang and Philpot, 2007). Therefore, the nearshore turbid
zone represents a challenging area for archaeologists in the search
for fully submerged archaeological sites.
These coastal seas are often characterized by a high variability in
the concentration of Suspended Particulate Matter (SPM). SPM is
generally composed of various fine grained constituents including
clay minerals, quartz, carbonates, organic matter, plankton and so
on (Berlamont et al., 1993). Tides, waves and wind forcing as well as
biological activity have an influence on the horizontal and vertical
distribution of the SPM in the water column and on the occurrence
of fluffy layers of fine-grained sediments on the sea floor (Mehta,
1986; Dyer, 1989). The fine-grained sediments are re-suspended
when the current-induced bottom shear stress exceeds a critical
value and are mixed up in the water column by turbulence.
Deposition occurs when the turbulent mixing becomes smaller
than the settling velocity of the SPM. Depending on the water depth
and the hydrodynamic forcing, the SPM is mixed up towards the
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M. Baeye et al. / Journal of Archaeological Science 66 (2016) 1e6
water surface, where they can be detected by remote sensing
techniques.
Mapping of suspended particulate matter (SPM) concentration
from ocean colour satellite imagery such as SeaWiFs, Meris or
MODIS-Aqua with 250e750 m spatial resolution has proven to be
an excellent source of data to describe and understand the surface
SPM distribution in the time and space domain (Trisakti et al.,
2005; Fettweis et al., 2007; Eleveld et al., 2008; Nechad et al.,
2010; Fettweis et al., 2012). Satellites such as Landsat-8 with an
even higher spatial resolution (30 m) show small-scale SPM concentration variations at the sea surface. These features are a sign of
the natural heterogeneity of hydrological, seafloor, bathymetrical
and biological conditions (Becker et al., 2013). Human activities,
such as dredging and disposal of dredged material, sand extraction,
aquaculture and offshore structures constructions impose further
local changes in hydrodynamics and sediment transport, and affect
turbidity, fine-grained sediment dynamics, and thus the SPM concentration in the water column, at the surface and on the sea floor
(Forrest et al., 2009; Fettweis et al., 2011; Capello et al., 2014; Van
Lancker and Baeye, 2015).
The effect of these small-scale changes can be detected by highresolution satellites, such as Landsat-8. An example is the turbid
wakes associated with offshore windfarms turbines (Vanhellemont
and Ruddick, 2014). The increase in SPM concentration in the wakes
of these structures is caused mainly by the increase of hard substrate surfaces in a soft sediment environment and the associated
massive bio-fouling (Baeye and Fettweis, 2015). Other studies have
shown that objects on the sea floor induce local scour pits (Quinn,
2006; Quinn and Boland, 2010) that can be periodically filled by
fine-grained sediments resulting in an increase of the sea floor
heterogeneity (Traykovski et al., 2004; Baeye et al., 2012). The aim
of this study is to investigate if fully submerged shipwrecks in the
nearshore generate SPM concentration signals that can be detected
by high-resolution ocean colour satellites such as Landsat-8. The
availability of detailed bathymetric data and surface SPM concentration maps make the Belgian nearshore area a relevant site for
investigating the link between the shipwreck, the scour signatures
at the sea bed and the surface signature in SPM concentration and
illustrate the potential of remote sensing mapping for underwater
archaeology.
2. Material and methods
2.1. Wreck sites and bathymetric data
In this study, four shipwreck sites near the port of Zeebrugge are
investigated: SS Sansip (1944), SS Samvurn (1945), SS Nippon (1938)
and SS Neutron (1965). Sansip, a 135 17 m US Liberty cargo ship
with a draft of 8.5 m sank after being mined on December 7, 1944.
On September 11, 1997 the fishing vessel N12 Arthur struck the site
and sank adjacent to Sansip. Samvurn, measuring 129 17 m, sank
after being mined on January 18, 1945 underway from Antwerp to
London. 7 crew and nine soldiers died. Nippon, a 138 18 m
Swedish steamship sank on September 14 1938 after colliding with
another vessel off the Wandelaar Lightship. Neutron, a 51 8 m
Dutch steel cargo vessel, foundered and sank on August 3 1965 after
hitting a wreck, presumed to be Sansip.
Full-coverage multibeam echosounder (MBES) data was made
available by the Flemish Hydrography, Coastal Division, Agency for
Maritime and Coastal Services, Flemish Ministry of Mobility and
Public Works. The MBES surveys of the wreck sites were conducted
using a dual head Kongsberg EM3002D, an RTK Septentrio
AsteRx2e GPS system and Applanix POS/MV 320 motion compensation system. The 1 m gridded data were rendered using ArcGIS v
10.1. Reference level of the water depths is Lowest Astronomical
Tide (LAT).
2.2. Satellite data
Landsat-8 was launched on February 11, 2013 with a ground
track repeat cycle of 16 days and a crossing time at 10:45 a.m. for
the study area. The Operational Land Imager (OLI) on Landsat-8 is a
nine band push broom scanner with a swath width of 185 km.
Suspended particulate matter (SPM) is retrieved using OLI bands 4
(red) and 5 (near infrared) at 30 m spatial resolution. Processing
included, among others, atmospheric correction and correction for
scattering by molecules and aerosols to retrieve water-leaving
radiance reflectance (details in Vanhellemont and Ruddick, 2014).
A set of 21 cloud-free Landsat-8 images, covering the different
seasonal, fortnightly and semidiurnal conditions, was used in this
study (Table 1). Fig. 1a is an original RGB Landsat-8 image of the
Belgian coastal zone area, and the derived SPM concentration map
is shown in Fig. 1b.
2.3. Hydrodynamic model
The tidal currents (direction and speed) and water elevation at
the time of each Landsat-8 image were modelled using an implementation of the 3D COHERENS hydrodynamic model to the
Belgian Continental Shelf (Luyten, 2013). The model covers an area
between 51 N and 51.92 N and between 2.08 E and 4.2 E.
Boundary conditions for this model were provided by the operational models OPTOS-NOS (covering the North Sea) and OPTOSCSM (covering the North-West European Continental Shelf).
Regarding the tidal currents, a counter-clockwise rotating tidal
wave is associated with the amphidromic point in the southern
North Sea resulting in a semi-diurnal tidal current ellipse that for
the study area is oriented WSW (ebb) e ENE (flood). The tidal range
in water elevation varies between 2.5 (super neap) and 5.0 (super
spring) m, with an average tidal range of 3.6 m.
Table 1
Satellite imagery and hydrodynamic model metadata and derivatives. 2013 data is in
italics, 2014 data in bold and * means no plumes were observed in Landsat-8 SPM
concentration map. The correlation coefficient is 0.99 between modelled current
direction (current dir; true north) and plume direction (plume dir; true north).
Neaps and springs are classified based on the median difference between high water
and low water elevation which is 3.6 m for the study area. Seasons are divided as
follows: [355e80] is winter, [80e172] is spring, [172e266] is summer, [266e355] is
fall.
Path
Day
Spring/neap
Season
Plume dir
Current dir
þ Speed (m/s)
199
199
199
199
199
199
200
200
199
199
199
199
199
199
200
200
200
200
200
200
200
200
216
232
248
280
344
159
303
75
91
107
139
235
251
34
82
162
226
258
290
306
neap
neap
spring
spring
spring
neap
spring
neap
spring
spring
spring
spring
neap
spring
spring
neap
neap
spring
neap
neap
neap
summer
summer
summer
summer
fall
fall
spring
fall
winter
spring
spring
spring
summer
summer
winter
spring
spring
summer
summer
fall
fall
042
060
076
121
208
278
*
54
105
213
217
239
074
085
241
253
066
235
240
*
*
047
064
068
124
219
264
161
54
108
224
221
232
072
078
241
244
066
231
241
287
348
0.40
0.82
1.08
0.13
0.34
0.52
0.18
0.54
0.24
0.43
0.28
0.67
0.81
0.59
0.72
0.75
1.02
0.73
0.75
0.17
0.21
M. Baeye et al. / Journal of Archaeological Science 66 (2016) 1e6
3
Fig. 1. (A) Landsat-8 image taken on day 280 (2013) under spring tide conditions. (B) Corresponding SPM concentration map. Black crosses indicate (mostly buried) shipwreck sites.
3. Results
3.1. Bathymetry
The four wreck sites under investigation are located within 5 km
of each other on a fine to medium sandy seafloor in less than 15 m
of water (Fig. 2, Table 2). All four sites display scour pits aligned
parallel to peak flow (Fig. 3). The sites of SS Sansip and SS Samvurn
have the largest and deepest scour pits, with both wrecks exposed
above the seafloor. SS Sansip and the remains of Arthur (Fig. 3a,
Table 2) are broken into four sections over an area of 150 40 m,
with the shallowest point on the vessel at 4.9 m LAT and the
deepest scour pit at 13.8 m LAT. Scouring occurs all around the site,
with the deepest pits immediately adjacent to the broken sections
of the vessels at the southern end of the site. Bedforms are developed to the northwest of the wreck site, with crests orientated
NNW-SSE. SS Samvurn, located 2 km southeast of SS Sansip, also
displays a well-developed scour pit (Fig. 3b), with maximum
scouring to a depth of 12.6 m LAT around the bow. The vessel appears largely intact, measuring 72 23 m, with the shallowest
point at 3.8 m LAT.
SS Neutron (Fig. 3c) and SS Nippon (Fig. 3d) are both buried
deeper in the seabed than SS Sansip and SS Samvurn and so less of
their superstructure is exposed to influence scour processes. SS
Neutron is imaged as two discrete sections in the MBES data, with
Fig. 2. Grainsize D50 (mm) and the locations of the 4 wreck sites.
Table 2
Grain size information and morphometrics for the four wreck sites. Dmin is the
shallowest point on each site and Dmax the deepest. DD ¼ Dmax Dmin.
Wreck
d50 (mm) classification
Dmin (m)
Dmax (m)
DD (m)
SS
SS
SS
SS
329 Medium sand
237-337 Fine-medium sand
249-399 Fine-medium sand
197-331 Fine-medium sand
7.7
4.9
3.8
8.6
11.3
13.8
12.6
11.8
3.6
8.9
8.8
3.2
Neutron
Sansip
Samvurn
Nippon
the southern section measuring 15 9 m and the northern section
measuring 7 9 m. The deepest scour pit is developed around the
structure at the northern end of the site, with a maximum recorded
depth of 11.3 m LAT. SS Nippon, the most easterly of the sites, appears intact, measuring 120 20 m. This is the lowest relief of all
four sites, with a variation of 3.2 m from the deepest scour pit
(11.8 m LAT) to the shallowest point on the wreck (8.6 m LAT).
3.2. Surface sediment concentration
SPM plumes are recorded originating from the sites of SS Sansip
and SS Samvurn during both flood (Fig. 4a) and ebb (Fig. 4b) phases
of the tide. No SPM plumes are recorded in association with the SS
Neutron or SS Nippon wreck sites in any of the Landsat-derived SPM
concentration maps. On the stronger flood tide, the plume from the
SS Samvurn site is directed to the NNE with a concentration of about
35 mg/l, whereas the SS Sansip site associated plume is not (yet)
well developed (Fig. 4a). On the weaker ebb tide, the SS Sansip and
SS Samvurn plumes are directed to the SSW (Fig. 4b) with concentrations of about 40 mg/l at a distance of 200 m from the wreck
sites (Fig. 5). In the northeast sector of the ebb tide SPM concentration map (Fig. 4b); increased SPM concentrations are associated
with turbid wakes of deep-draft vessels. Based on all 21 images, the
overall average ratio between the plume and background (i.e. inside
vs. outside the plume) concentration at 200 m from the two wreck
sites, is about 1.4. For spring tide periods (stronger currents) in
winter (overall more SPM in watercolumn) SPM concentrations are
much higher than for neap tides (weaker currents) during summer
(overall less SPM), however that ratio remains more or less 1.4.
Fig. 6a synthesizes all observed plume directions in a polar plot,
clearly evidencing the dominant ebb and flood tidal phase plumes.
Note that SPM plumes were observed immediately before, during
and immediately after maximum current velocities were reached
(Fig. 6b). Plume directions and the associated tidal current directions from the hydrodynamic model (Table 1) correlate well.
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M. Baeye et al. / Journal of Archaeological Science 66 (2016) 1e6
Fig. 3. MBES-derived digital elevation models of the wreck sites: A: SS Sansip; B: SS Samvurn; C: SS Neutron; D: SS Nippon. Depths in metre with reference LAT (lowest astronomical
tide).
Fig. 4. (A) flood phase during day 235 (2014) under neap tide and partly cloudy (see white areas); (B), ebb phase during day 91 (2014) under spring tide. ? is an unknown shipwreck.
White circle around SS Sansip through plume at a distance of 200 m from wreck (see Fig. 5).
M. Baeye et al. / Journal of Archaeological Science 66 (2016) 1e6
5
The occurrence of plumes is further associated to all the seasons,
the reason why there are less observations winter, is because of the
lower amount of cloud-free images in winter for our study area.
Shipwrecks on the seabed are hard substrates that are colonized by
epifauna (Zintzen et al., 2008). The epifaunal species produce
(pseudo-) faecal pellets that degrade, get in suspension and likely
contribute to the SPM concentration in the area.
4.2. Wreck detection using ocean colour data
Fig. 5. Circular SS Sansip transect (see white circle in Fig. 4B) through SS Sansip plume
with radius of 200 m around the shipwreck site.
4. Discussion
4.1. Conceptual model
During slack tidal phases, sediments in suspension settle down
and create fluffy mud deposits up to 30 cm near the seabed (Baeye
et al., 2012). We propose that the scour pits play an important role
in the development of the SPM plumes, as they act as sinks where
fine-grained suspended material is preferentially deposited during
slacks and alternately act as sources for suspended material when
the bottom current increases again. The duration of the slack tide
(dependent on the prevailing meteorological forcing) defines how
much infilling occurs. The SPM plume develops immediately before
maximum ebb or flood current is reached, during maximum current and immediately after (see Fig. 6a and b). Therefore it is likely
that a plume develops (i.e. becoming more turbid and growing in
length); and as the current is turning anti-clockwise, they tend to
be slightly bent to the right.
Furthermore, the tide is semi-diurnal assuming 4 SPM plumes
that develop on a daily basis (2 during ebb and 2 during flood).
Regardless the strong or weaker hydrodynamic forcing, SPM
plumes occur under spring and neap tide conditions respectively.
The very well developed SPM plumes from the SS Sansip and SS
Samvurn sites likely reflect the large amount of wreck structure
exposed at both sites, with the level of vertical exposure (DD)
recorded as 8.9 m and 8.8 m respectively (Table 2). As a consequence, increased turbulence for resuspension of SPM explains the
increased surface SPM concentration downstream from the two
shipwrecks. Lower DD values of 3.2 m and 3.6 m respectively at the
SS Nippon and SS Neutron sites indicate less bathymetrically complex sites, with more poorly developed scour pits and lower turbulent effects.
In addition to the size and geometry of the wrecks and their
scour pits, tidal hydrodynamic forcing also controls the turbulence
and vertical mixing capacity in the water column. SPM plumes are
observed from space only when the SPM reaches the water surface;
therefore water depth is another controlling factor in detecting
wrecks using this technique. In Fig. 4a the plume associated with
the SS Sansip site is not so pronounced as for SS Samvurn. The latter
is located in slightly shallower water depths. In addition, the
Landsat-8 image was acquired under neap tide conditions (tidal
range of 3 m) with weaker tidal currents. Fig. 4b corresponds to
spring tide conditions (tidal range of 4 m) and stronger currents
resulting in a very pronounced SPM plume for SS Sansip. At times in
the tidal cycle there is likely to be a complete absence of plumes,
namely during slack tides when currents are strongly decreased
(<0.25 m/s) (see Table 1). That is exactly what can be inferred from
Fig. 6a e that the SPM plumes do not occur along the NNW-SSE
axis. This is also confirmed by the fact that the null observations
of plumes (see * in Table 1) correspond with lower water currents
Fig. 6. (A) Plume rose diagram based on all observations from the 21 Landsat-8 images, directions are “heading towards”. (B) Average tidal current ellipse with ebb currents (WSW
and 0.6 m/s) being slightly weaker than the flood (ENE and 0.8 m/s). Colourbar (m) refers to water depth. (For interpretation of the references to colour in this figure legend, the
reader is referred to the web version of this article.)
6
M. Baeye et al. / Journal of Archaeological Science 66 (2016) 1e6
(<0.25 m/s).
The ability to detect the presence of submerged shipwrecks
from space is of benefit to archaeological scientists and resource
managers interested in locating wrecks and investigating processes
driving their evolution. Landsat-8 data is free and therefore the
method presented in this study is an inexpensive alternative to
acoustic and laser survey techniques. Although satellite data cannot
match acoustic and laser data in terms of resolution, it does offer
the user a much broader view of the coastal landscape and could be
used to supplement the traditional survey techniques, allowing
researchers delineate high potential sites using the SPM technique
for follow-up surveys using acoustics and bathymetric LiDAR.
Another benefit of the SPM detection technique is that it provides
insights into hydrodynamic and sedimentary processes acting on
sites and quantitative data with respect to sediment dynamics and
site evolution.
5. Conclusions
Surface SPM plumes associated with fully submerged shipwrecks were observed and described in terms of wreck size and
geometry, associated scour pits and seabed grain size, and hydrodynamics. This particular type of SPM concentration heterogeneity
at the surface is now explained and clearly distinguished from ship
wakes generating SPM plumes since the latter do not align with
water current. These findings allow marine archaeologists better
mapping and monitoring of shipwreck sites. For example, seabed
evolution is subjected to changes such as migrating sand dunes or
longer-term sediment transport (un-) burying the wrecks. So SPM
plumes are indicators that a shipwreck is exposed at the seabed and
certainly not buried. This indicator may also be helpful to plan site
visits, to discover new sites, and to protect shipwrecks.
Acknowledgements
This work was supported by the HIGHROC project (HIGH spatial
and temporal Resolution Ocean Colour products and services),
which is funded by the European Community's Seventh Framework
Programme (FP7/2007-2013) under grant agreement n 606797.
SPM concentration maps were supplied by Quinten Vanhellemont,
and together with Kevin Ruddick, both are thanked for fruitful
discussions. Laurence Vigin provided the geographic data on the
bastien Legrand the tides and currents data
shipwreck sites and Se
from the operational hydrodynamic model. Full-coverage multibeam echosounder (MBES) data was made available by the Flemish
Hydrography, Coastal Division, Agency for Maritime and Coastal
Services, Flemish Ministry of Mobility and Public Works.
References
Baeye, M., Fettweis, M., Legrand, S., Dupont, Y., Van Lancker, V., 2012. Mine burial in
the seabed of high- turbidity area - findings of a first experiment. Cont. Shelf
Res. 43, 107e119. http://dx.doi.org/10.1016/j.csr.2012.05.009.
Baeye, M., Fettweis, M., 2015. In situ observations of suspended particulate matter
plumes at an offshore wind farm, southern North Sea. Geo-Mar. Lett. 35 (4),
247e255. http://dx.doi.org/10.1007/s00367-015-0404-8.
€, A., Ernstsen, V.B., Winter, C., Hebbeln, D.,
Becker, M., Schrottke, K., Bartholoma
2013. Formation and entrainment of fluid mud layers in troughs of subtidal
dunes in an estuarine turbidity zone. J. Geophys. Res. Oceans 118 (4),
2175e2187. http://dx.doi.org/10.1002/jgrc.20153.
Berlamont, J., Ockenden, M., Toorman, E., Winterwerp, J., 1993. The characterisation
of cohesive sediment properties. Coast. Eng. 21, 105e128.
Capello, M., Cutroneo, L., Ferranti, M.P., Budillon, G., Bertolotto, R.M., Ciappa, A.,
Cotroneo, Y., Castellano, M., Povero, P., Tucci, S., 2014. Simulations of dredged
sediment spreading on a Posidonia oceanica meadow off the Ligurian coast,
Northwestern Mediterranean. Mar. Pollut. Bull. 79, 196e204. http://dx.doi.org/
10.1016/j.marpolbul.2013.12.014.
Dyer, K.R., 1989. Sediment processes in estuaries: future research requirements.
J. Geophys. Res. 94 (C10), 14327e14339.
Eleveld, M.A., Pasterkamp, R., van der Woerd, H.J., Pietrzak, J.D., 2008. Remotely
sensed seasonality in the spatial distribution of sea-surface suspended particulate matter in the southern North Sea. Estuar. Coast. Shelf Sci. 80, 103e113.
Fettweis, M., Nechad, B., Van den Eynde, D., 2007. An estimate of the suspended
particulate matter (SPM) transport in the southern North Sea using SeaWiFS
images, in situ measurements and numerical model results. Cont. Shelf Res. 27,
1568e1583.
Fettweis, M., Baeye, M., Francken, F., Lauwaert, B., Van den Eynde, D., Van
Lancker, V., Martens, C., Michielsen, T., 2011. Monitoring the effects of disposal
of fine sediments from maintenance dredging on suspended particulate matter
concentration in the Belgian nearshore area (southern North Sea). Mar. Pollut.
Bull. 62, 258e269. http://dx.doi.org/10.1016/j.marpolbul.2010.11.002.
Fettweis, M., Monbaliu, J., Nechad, B., Baeye, M., Van den Eynde, D., 2012. Weather
and climate related spatial variability of high turbidity areas in the North Sea
and the English Channel. Methods Oceanogr. 3e4, 25e29. http://dx.doi.org/
10.1016/j.mio.2012.11.001.
Forrest, B.M., Keeley, N.B., Hopkins, G.A., Webb, S.C., Clement, D.M., 2009. Bivalve
aquaculture in estuaries: review and synthesis of oyster cultivation effects.
Aquaculture 298, 1e15. http://dx.doi.org/10.1016/j.aquaculture.2009.09.032.
Luyten, P., 2013. A Coupled Hydrodynamical-ecological Model for Regional and
Shelf Seas User Documentation Version 2.5.1. http://www2.mumm.ac.be/
coherens/.
Mehta, A.J., 1986. Characterisation of cohesive sediment properties and transport
processes in estuaries. In: Mehta, A.J. (Ed.), Estuarine Cohesive Sediment Dynamics, Lecture Notes on Coastal and Estuarine Studies. Springer-Verlag,
pp. 290e325.
Nechad, B., Ruddick, K., Park, Y., 2010. Calibration and validation of a generic
multisensor algorithm for mapping of total suspended matter in turbid waters.
Remote Sens. Environ. 114, 854e866.
Plets, R., Quinn, R., Forsythe, W., Westley, K., Bell, T., Benetti, S., McGrath, F.,
Robinson, R., 2011. Using multibeam echo-sounder data to identify shipwreck
sites: archaeological assessment of the Joint Irish bathymetric survey data. Int. J.
Naut. Archaeol. 40 (1), 87e98.
Quinn, R., Boland, D., 2010. The role of time-lapse bathymetric surveys in assessing
morphological change at shipwreck sites. J. Archaeol. Sci. 37 (11), 2938e2946.
Quinn, R., 2006. The role of scour in shipwreck site formation processes and the
preservation of wreck-associated scour signatures in the sedimentary record e
evidence from seabed and sub-surface data. J. Archaeol. Sci. 33 (10), 1419e1432.
Quinn, R., Dean, M., Lawrence, M., Liscoe, S., Boland, D., 2005. Backscatter responses
and resolution considerations in archaeological side-scan sonar surveys: a
control experiment. J. Archaeol. Sci. 32 (8), 1252e1264.
Shih, Peter TY., Ya-Hsing, C., Jie-Chung, C., 2014. Historic shipwreck study in
Dongsha Atoll with bathymetric LiDAR. Archaeol. Prospect. 23, 139e146.
Traykovski, P., Geyer, R., Sommerfield, C., 2004. Rapid sediment deposition and
finescale strata formation in the Hudson estuary. J. Geophys. Res. 109.
Trisakti, B., Parwati, Budhiman, S., 2005. Study of MODIS-AQUA data for mapping
total suspended matter (TSM) in coastal waters. Remote Sens. Earth Sci. 2,
19e31.
Van Lancker, V., Baeye, M., 2015. Wave glider monitoring of sediment transport and
dredge plumes in a shallow marine sandbank environment. PLoS One 10 (6),
e0128948. http://dx.doi.org/10.1371/journal.pone.0128948.
Vanhellemont, Q., Ruddick, K., 2014. Turbid wakes associated with offshore wind
turbines observed with Landsat 8. Remote Sens. Environ. 145, 105e115. http://
dx.doi.org/10.1016/j.rse.2014.01.009.
Wang, C.K., Philpot, W.D., 2007. Using airborne bathymetric lidar to detect bottom
type variation in shallow waters. Remote Sens. Environ. 106 (1), 123e135.
Zintzen, V., Norro, A., Massin, C., Mallefet, J., 2008. Spatial variability of epifaunal
communities from artificial habitat: shipwrecks in the Southern Bight of the
North Sea. Estuar. Coast. Shelf Sci. 76 (2), 327e344.