The sound of the sand from the Dutch shores
Ruth, Saskia M. van; Hettinga, Frans ; Dekker, Pieter ; Fitzpatrick, Dara - \ 2019
Applied Acoustics 154 (2019). - ISSN 0003-682X - p. 1 - 10.
Acoustics - Beach - Broad Acoustic Resonance Dissolution Spectroscopy - Netherlands - Provenance - Resonance - Sound spectroscopy
In this study, we examine sand from the Dutch shores to link its unique acoustic traits to the source of the sand. Sand from nine locations along the beaches of the Netherlands, over a stretch of 187 km, were collected and subjected to Broad Acoustic Resonance Dissolution Spectroscopy analysis (BARDS). Sand sampling positions with respect to the distance to the high water line were compared as well. Temporal acoustic profiles, resulting from gas released from the sand particles in an acidic solution over time, were used to compare the sands from the various locations and positions along the shore. These BARDS patterns were compared with those of model sand samples composed of CaCO 3 , CaCO 3 /quartz mixtures, and ground sea shell/quartz mixtures to understand the phenomena. BARDS analysis allowed accurate measurements of the unique acoustic traits of the sands, which appeared good indicators of the source of the sand. The results show that both the composition and morphology of the sand determine the acoustic profiles. The proportion of seashells in the sand plays an important role in the acoustic signatures of the sands of the Dutch shores. The carbonate components of the shells and the shells’ morphology result in dissolution of the carbonates under acidic conditions and subsequent release of CO 2 in specific patterns. These specific patterns allow us to establish the source of the sand – with help of multivariate statistical methods. Evidently, the current study shows that ‘listening’ to the sound of sand reveals interesting information about its identity and origin.
A Sharp View on River Dune Transition to Upper Stage Plane Bed
Naqshband, S. ; Hoitink, A.J.F. ; Mcelroy, B. ; Hurther, D. ; Hulscher, S.J.M.H. - \ 2017
Geophysical Research Letters 44 (2017)22. - ISSN 0094-8276 - p. 11437 - 11444.
Acoustics - Dunes - Sediment transport
Sandy river beds are dominated by rhythmic features known as dunes. Experimental investigations of turbulent flow and sediment transport over dunes have predominantly focused on equilibrium flows that are rare in natural rivers. Using a novel acoustic instrument over migrating dunes in a laboratory setting, we quantify a number of dynamical properties that are crucial in our understanding and modeling of dune morphology and kinematics, particularly under nonequilibrium flows during dune transition to upper stage plane bed. Measured sediment transport distributions reveal a positive spatial lag between dune crest and maximum sediment transport rate that eventually caused washing out of dunes. Bed load was entirely captured in dune troughs, contributing to dune translation where most of suspended load was advected further downstream contributing to dune deformation. Measured bypass fraction was about 76%, which means that only 24% of the total sediment load at the dune crest contributed to dune migration.
Acoustic dose-behavioral response relationship in sea bass (Dicentrarchus labrax) exposed to playbacks of pile driving sounds
Kastelein, Ronald A. ; Jennings, Nancy ; Kommeren, Aimée ; Helder-Hoek, Lean ; Schop, Jessica - \ 2017
Marine Environmental Research 130 (2017). - ISSN 0141-1136 - p. 315 - 324.
Acoustics - Behavior - Marine fish - Offshore industry - Pile driving - Sea bass - Startle response - Wind park
The foundations of offshore wind turbines are attached to the sea bed by percussion pile driving. Pile driving sounds may affect the behavior of fish. Acoustic dose-behavioral response relationships were determined for sea bass in a pool exposed for 20 min to pile driving sounds at seven mean received root-mean-square sound pressure levels [SPLrms; range: 130-166 dB re 1 μPa; single strike sound exposure level (SELss) range: 122-158; 6 dB steps]. Initial responses (sudden, short-lived changes in swimming speed and direction) and sustained responses (changes in school cohesion, swimming depth, and speed) were quantified. The 50% initial response threshold occurred at an SELss of 131 dB re 1 μPa2 s for 31 cm fish and 141 dB re 1 μPa2 s for 44 cm fish; the small fish thus reacted to lower SELss than the large fish. Analysis showed that there is no evidence, even at the highest sound level, for any consistent sustained response to sound exposure by the study animals. If wild sea bass are exposed to pile driving sounds at the levels used in the present study, there are unlikely to be any adverse effects on their ecology, because the initial responses after the onset of the piling sound observed in this study were short-lived.
Harbour porpoise movement strategy affects cumulative number of animals acoustically exposed to underwater explosions
Aarts, Geert ; Benda-Beckmann, Alexander M. Von; Lucke, K. ; Özkan Sertlek, H. ; Bemmelen, Rob Van; Geelhoed, Steve C.V. ; Brasseur, Sophie ; Scheidat, Meike ; Lam, Frans Peter A. ; Slabbekoorn, Hans ; Kirkwood, Roger - \ 2016
Marine Ecology Progress Series 557 (2016). - ISSN 0171-8630 - p. 261 - 275.
Acoustics - Anthropogenic sound - Cumulative effects - Impact assessment - Individual-based model - Marine mammals - Population consequences of disturbance - Species distribution
Anthropogenic sound in the marine environment can have negative consequences for marine fauna. Since most sound sources are intermittent or continuous, estimating how many individuals are exposed over time remains challenging, as this depends on the animals' mobility. Here we explored how animal movement influences how many, and how often, animals are impacted by sound. In a dedicated study, we estimated how different movement strategies affect the number of individual harbour porpoises Phocoena phocoena receiving temporary or permanent hearing loss due to underwater detonations of recovered explosives (mostly WWII aerial bombs). Geo-statistical distribution models were fitted to data from 4 marine mammal aerial surveys and used to simulate the distribution and movement of porpoises. Based on derived dose-response thresholds for temporary (TTS) or permanent threshold shifts (PTS), we estimated the number of animals affected in a single year. When individuals were free-roaming, an estimated 1200 and 24 000 unique individuals would suffer PTS and TTS, respectively. This equates to respectively 0.50 and 10% of the estimated North Sea population. In contrast, when porpoises remained in a local area, fewer animals would receive PTS and TTS (1100 [0.47%] and 15 000 [6.5%], respectively), but more individuals would be subjected to repeated exposures. Because most anthropogenic sound-producing activities operate continuously or intermittently, snapshot distribution estimates alone tend to underestimate the number of individuals exposed, particularly for mobile species. Hence, an understanding of animal movement is needed to estimate the impact of underwater sound or other human disturbance.