Atlas of Bedforms in the Western Mediterranean (eBook)

Dr. Jorge Guillén is a Research Scientist at the Institute of Marine Sciences-CSIC (Barcelona, Spain). He graduated in geology (University of Barcelona) and completed his PhD in Marine Sciences by the Polytechnic University of Catalonia.  Main topics of his research are sediment dynamics and morphodynamics in coastal areas and the continental shelf under different timescales, using both in situ and remote observations. Dr. Juan Acosta-Yepes is a geologist (Universidad Complutense de Madrid, Spain), and PhD in Marine Sciences (University of Barcelona). He worked for more than 35 years at Instituto Español de Oceanografía as Oceanographer and Senior Scientist (actually retired). His research interests have been marine geology and geophysics, geomorphology/morphotectonic, and the systematic mapping of the Spanish Exclusive Economic Zone. Dr. Francesco. L. Chiocci is Full Professor at Rome University, Italy. He graduated in geology and completed his PhD in Earth Sciences at the University “La Sapienza”, Rome. At present he is mainly involved in Italian and European research projects (MAGIC, RITMARE-DEEP SEA,…) for acquiring high-resolution morphobathymetry and producing geohazard maps of the continental margins of Italy and to create synthetic products on specific aspects of data and knowledge collected. Dr Albert Palanques, initially trained as a Geologist (degree in 1981, University of Barcelona), he got a PhD in Marine Sciences (1987, Polytechnic University of Catalonia). He is presently Research Professor and Director of the Institute of Marine Sciences (CSIC) in Barcelona. Main topics of his research are sediment and geochemical fluxes, anthropogenic impact on marine sedimentary systems and sedimentary processes in continental margins.

Contents 6
Introduction to the Atlas 10
Bedform Analysis and Main Physical Processes 13
1 Bedform Mapping: Multibeam Data Processing, Metadata and Spatial Data Services 14
Abstract 14
1.1 Introduction: Multibeam Data Processing 14
1.2 Metadata 15
1.3 Spatial Data Services 16
1.4 The INSPIRE Directive 17
1.5 Conclusions 17
References 17
2 Methods for Analysing Bedform Geometry and Dynamics 18
Abstract 18
2.1 Introduction 18
2.2 Review of Methods 19
2.2.1 Bedform Orientation and Wavelength 19
2.2.2 Superimposed Bedforms and Identification of Crests and Troughs 20
2.2.3 Bedform Dynamics 20
2.3 Discussion 21
2.4 Conclusions 22
Acknowledgments 22
References 22
3 Principles of Physical Modelling of Bedforms Under Waves and Currents 25
Abstract 25
3.1 Introduction 25
3.2 Physical Modelling in Three Steps 25
3.3 Two Simple Cases 26
3.4 Concluding Remarks 27
Acknowledgments 27
References 27
4 Modelling Bedforms on the Continental Shelf 28
Abstract 28
4.1 Introduction 28
4.2 Tidal Sand Waves 29
4.3 Tidal Sand Banks 30
4.4 Long Bed Waves 31
4.5 Shoreface-Connected Sand Ridges 31
4.6 Future Perspectives 32
Acknowledgements 32
References 32
5 Internal Waves and Bedforms 34
Abstract 34
5.1 Introduction 34
5.2 Internal Wave Impact on Sediment 35
5.3 Observational Setup 36
5.4 Discussion 37
References 37
6 Turbidity Current Bedforms 38
Abstract 38
6.1 Turbidity Current Bedforms 38
6.2 Bedform Stability Diagram for Turbidity Currents 39
6.3 Discussion 40
References 41
7 Dense Shelf Water Cascading and Associated Bedforms 43
Abstract 43
7.1 Introduction 43
7.2 Dense Shelf Water Cascading in the Western Mediterranean 44
References 47
8 Currents in the Western Mediterranean Basin 49
Abstract 49
8.1 Introduction 49
8.2 The Mediterranean Basin 50
8.3 Methods and Observations 50
8.4 Surface Circulation 52
8.5 Intermediate Circulation 53
8.6 Deep Circulation 53
Acknowledgments 54
References 54
Bedforms in the Coastal Zone 56
9 Bedforms as Self-organized Patterns 57
Abstract 57
9.1 Introduction 57
9.2 Forced or Self-organized Response? 57
References 59
10 Beach Cusps 60
Abstract 60
10.1 Introduction 60
10.2 Modelling Beach Cusp Formation 61
Bibliography 62
11 Km-Scale Shoreline Sand Waves 63
Abstract 63
11.1 Shoreline Undulations 63
11.2 Km-Scale Shoreline Sand Waves 63
11.3 Self-organized Origin and Evolution 65
Acknowledgments 67
References 67
12 KM-Scale Shoreline Sand Waves In The Western Mediterranean Sea 68
Abstract 68
12.1 Introduction 68
12.2 Open Coasts 69
12.3 Deltas 71
12.4 Sheltered Shores 73
Acknowledgments 74
References 74
13 Nearshore Sand Bars 76
Abstract 76
13.1 Motivation 76
13.2 Classification and Morphological Characteristics and Dynamics 76
13.2.1 Shore-Parallel Bars (Straight or Crescentic) 76
13.2.2 Transverse Bars 77
13.3 Physical Processes for Their Development and Dynamics 79
13.3.1 Shore-Parallel Straight Bars 79
13.3.2 Crescentic Bars and Transverse TBR Bars (Type 1) 80
13.3.3 Transverse Medium-Energy Finger Bars (Type 2) 80
13.3.4 Transverse Low-Energy and Large-Scale Finger Bars (Types 3 and 4) 80
Acknowledgments 81
References 81
14 Nearshore Sand Bars on Western Mediterranean Beaches 83
Abstract 83
14.1 Introduction 84
14.2 Observations of Nearshore Sand Bars in the Western Gulf of Lions, France 84
14.3 Observations of Nearshore Sand Bars on Catalan Beaches, Spain 84
14.3.1 Ebro Delta 84
14.3.2 Llobregat Delta (Barcelona and Castelldefels) 85
14.4 Summary and Comparison with Nearshore Bars on Other Coasts 87
Acknowledgments 90
References 90
15 Contemporary Subaqueous Dune Field Development Over an Abandoned River Mouth (Ebro Delta) 91
Abstract 91
15.1 Introduction 92
15.2 General Setting 92
15.3 Data Collection 93
15.4 Results and Discussion 93
15.5 Conclusions 94
Acknowledgments 95
References 95
16 Bedforms on the Lowermost Reach of the Tiber River (Rome, Italy): Preliminary Results from Integrated Geophysical Surveys and Samplings 96
Abstract 96
16.1 Introduction 97
16.2 Methods 97
16.3 Results 98
16.4 Final Remarks 99
Acknowledgments 99
References 99
Bedforms in Prodeltas and Sorted Bedforms 100
17 Holocene Muddy Bedforms on the Llobregat River Prodelta Wedge 101
Abstract 101
17.1 Introduction-Study Area 102
17.2 Methods 103
17.3 Results-Discussion 103
17.4 Conclusions 105
Acknowledgments 105
References 105
18 Prodeltaic Undulations and Hyperpycnal Flows (I): Morphological Observations 107
Abstract 107
18.1 Introduction 108
18.2 Sediment Supply of Short, Mountainous Rivers 108
18.3 Morphological Observations 109
18.4 Diagnostic Morphological Criteria Compatible with Hyperpycnal Flow Genesis 111
Acknowledgments 112
References 112
19 Prodeltaic Undulations and Hyperpycnal Flows (II): Evolutionary Trends 113
Abstract 113
19.1 Introduction 114
19.2 Holocene Prodeltaic Wedges in the Mediterranean Sea 114
19.3 Evidence of Progressive Undulation Development 115
19.4 Evolutionary Trends Compatible with Sediment Flow Activity 116
Acknowledgments 119
References 119
20 Sorted Bedforms Along the Egadi Islands Continental Shelf (Southern Tyrrhenian) 121
Abstract 121
20.1 Introduction-Study Area 122
20.2 Methods 123
20.3 Results-Discussion 123
20.4 Conclusions 125
Acknowledgments 125
References 125
21 Sorted Bedforms Developed on Sandy Deposits Derived from Small Ephemeral Streams (Catalan Continental Shelf) 127
Abstract 127
21.1 Introduction 128
21.2 Methods 128
21.3 Results 128
21.4 Discussion and Conclusions 129
Acknowledgments 132
References 132
22 Dynamics of Sorted Bedforms on a Shallow Infralittoral Prograding Wedge Influenced by Dredging (El Masnou, NW Mediterranean) 134
Abstract 134
22.1 Introduction 135
22.2 Methods 136
22.3 Results 136
22.3.1 Sorted Bedform Characteristics 136
22.3.2 Short-Term Bedform Evolution 136
22.4 Discussion and Conclusions 136
Acknowledgments 139
References 139
23 Sorted Bedforms Along the Continental Shelf of Western Sardinia 141
Abstract 141
23.1 Introduction 141
23.2 Methods 144
23.3 Results 144
23.4 Discussion and Conclusions 145
Acknowledgments 145
References 145
Bedforms in the Continental Shelf 146
24 Sedimentary Bedforms in the Menorca Channel Region, Balearic Islands (Western Mediterranean) 147
Abstract 147
24.1 Study Area 148
24.2 Methods 148
24.3 Results and Discussion 149
Acknowledgments 152
References 152
25 Dome Dunes on the Inner to Middle Shelf Transition on a Temperate-Water Carbonate Sediment Shelf. Pitiusas Islands 154
Abstract 154
25.1 Introduction 154
25.2 Methods 156
25.3 Results 156
25.4 Discussion and Conclusions 156
Bibliography 159
26 Trawl Marks and Dredge Spoils as Examples of Seabed Anthropic Alteration on Sediments (Menorca Shelf) 161
Abstract 161
26.1 Introduction 162
26.2 Methods 162
26.3 Results 162
26.3.1 Trawl Marks 162
26.3.2 Dumping of Dredged Sediment 163
26.4 Discussion and Conclusions 163
Acknowledgments 165
Bibliography 165
27 Sand Ridges on the Mid-Outer Valencia Continental Shelf 167
Abstract 167
27.1 Introduction, Study Area and Methods 167
27.2 Results and Discussion 169
27.3 Conclusions 170
Acknowledgments 170
References 170
28 Subaqueous Dune Fields on the Marine Protected Area Around the Cabrera Archipelago (Balearic Islands) 172
Abstract 172
28.1 Introduction 173
28.2 Methods 174
28.3 Results 174
28.3.1 The Northern Dune Field (Na Foradada Island) 174
28.3.2 The Eastern Dune Field (Sa Conills and Na Redona Islands) 175
28.3.3 The Southern Dune Field (Es Estells islands) 176
28.4 Discussion and Concluding Remarks 176
Acknowledgments 177
References 178
29 Subaqueous Dunes Over Sand Ridges on the Murcia Outer Shelf 179
Abstract 179
29.1 Introduction 180
29.2 Methods 180
29.3 Results 181
29.3.1 Sand Ridges 181
29.3.2 Subaqueous Dunes 181
29.4 Discussion and Conclusions 183
Acknowledgments 183
References 183
Bedforms and Benthos 185
30 Bedforms as Benthic Habitats: Living on the Edge, Chaos, Order and Complexity 186
Abstract 186
30.1 Study Area 186
30.2 Methodology 186
30.3 Results 186
Acknowledgments 189
References 189
31 Benthic Communities on Shallow Sedimentary Bottoms in the Western Mediterranean 190
Abstract 190
31.1 Introduction 191
31.2 Benthic Communities 191
31.2.1 Very Coarse Bottoms 191
31.2.2 Sandy Bottoms 191
31.2.3 Fine-Grained Bottoms 192
31.2.4 Meadows 194
31.2.5 Maërl Beds 196
31.3 Concluding Remarks 196
References 197
32 Characterization of Benthic Communities in a Subaqueous Dune Field on the Continental Shelf (Mar Menor, Western Mediterranean) 198
Abstract 198
32.1 Introduction 198
32.2 Methods 199
32.3 Results 200
32.3.1 Subaqueous Dunes 200
32.3.2 Habitat Types and Benthic Communities 200
32.3.2.1 The Maërl Community 200
32.3.2.2 The Transition Community 204
32.3.2.3 The Fine-Sediment Community 204
32.4 Concluding Remarks 204
Acknowledgments 204
References 204
33 Bio and Anthropogenic Disturbance of Maërl Communities Settled on Subaqueous Dunes on the Mar Menor Continental Shelf (Western Mediterranean) 206
Abstract 206
33.1 Introduction 207
33.2 Maërl Beds 208
33.3 Biogenic Disturbance 208
33.4 Anthropogenic Disturbance 209
33.5 Concluding Remarks 210
Acknowledgments 210
References 210
Beforms in Submarine Canyons 211
34 Bedforms in the Southern Submarine Canyons of the Balearic Islands (Western Mediterranean) Interpreted as Cyclic Steps 212
Abstract 212
34.1 Introduction 213
34.2 Methods 214
34.3 Results-Discussion 215
34.4 Conclusions 216
Acknowledgments 216
References 216
35 Cyclic Steps at the Head of Channelized Features Along the Calabrian Margin (Southern Tyrrhenian Sea, Italy) 218
Abstract 218
35.1 Introduction and Study Area 219
35.2 Methods 219
35.3 Results and Discussion 219
Acknowledgments 222
References 222
36 Potential Cyclic Steps in a Gully System of the Gulf of Palermo (Southern Tyrrhenian Sea) 223
Abstract 223
36.1 Introduction-Study Area 224
36.2 Methods 224
36.3 Results-Discussion 224
36.4 Conclusions 228
Acknowledgments 228
References 228
37 Bedforms Feeding and Bedforms Fed by Canyon Activity Around Punta Alice Promontory (Calabria Ionian Margin, Italy) 229
Abstract 229
37.1 Introduction 229
37.2 Data and Methods 230
37.3 Results and Discussions 230
Acknowledgments 233
References 233
38 Examples of Sediment Waves in and Around Submarine Canyons of the North Alboran Sea 235
Abstract 235
38.1 Introduction and Methods 235
38.2 Results and Discussion 236
Acknowledgments 240
References 240
39 Sediment Waves at the Mouth of the Almanzora-Alías-Garrucha Canyon 241
Abstract 241
39.1 Introduction 241
39.2 Methods 242
39.3 Results and Discussion 242
References 244
Slope and Deep Bedforms 245
40 Large Sediment Waves Over the Gulf of Roses Continental Slope (NW Mediterranean) 246
Abstract 246
40.1 Introduction 247
40.2 Methods 247
40.3 Results and Discussion 248
40.4 Conclusions 250
Acknowledgments 250
References 250
41 Large-Scale Fine-Grained Sediment Waves Over the Gulf of Valencia Continental Slope (NW Mediterranean) 252
Abstract 252
41.1 Introduction 253
41.2 Methods 253
41.3 Results and Discussion 254
41.4 Conclusions 257
Acknowledgments 257
42 Generation of Bedforms by the Mediterranean Outflow Current at the Exit of the Strait of Gibraltar 259
Abstract 259
42.1 Introduction 260
42.2 Results and Discussion 260
42.3 Concluding Remarks 265
Acknowledgments 265
43 Bedforms on the Distal Valencia Channel and Turbidite System 267
Abstract 267
43.1 Introduction 268
43.2 Methods 269
43.3 Results and Discussion 269
Acknowledgments 271
References 271
44 Small-Scale Bedforms Generated by Gravity Flows in the Aeolian Islands 272
Abstract 272
44.1 Introduction 273
44.2 Data and Methods 273
44.3 Results and Discussions 274
Acknowledgments 276
References 276
45 Large-Scale Bedforms on Volcaniclastic Aprons Around the Aeolian Islands (Italy) 278
Abstract 278
45.1 Introduction 279
45.2 Data and Methods 279
45.3 Results and Discussion 279
Acknowledgments 283
References 283
46 Deep-Water, Large-Scale Sediment Waves Bounded by the Valencia Channel 284
Abstract 284
46.1 Introduction and Methods 284
46.2 Results and Discussion 285
References 290
List of Reviewers 291