Wind speeds over the world’s oceans have increased over the past two decades, as have wave heights. Studies of climate change typically consider measurements or predictions of temperature over extended periods of time. Climate, however, is much more than temperature. Over the oceans, changes in wind speed and the surface gravity waves generated by such winds play an important role. We used a 23-year database of calibrated and validated satellite altimeter measurements to investigate global changes in oceanic wind speed and wave height over this period. We find a general global trend of increasing values of wind speed and, to a lesser degree, wave height, over this period. The rate of increase is greater for extreme events as compared to the mean condition.

https://researchbank.swinburne.edu.au/file/bca43746-6f16-4ad2-a4b7-27f8d8d60fed/1/PDF (Published version).pdf

Global trends in wind speed and wave height over the past 25 years

Correlation of sidescan backscatter with grain size distribution of surficial seabed sediments

http://ecite.utas.edu.au/141411/1/141411%20-%20Identifying%20the%20consequences%20of%20ocean%20sprawl%20for%20sedimentary%20habitats.pdf

Identifying the consequences of ocean sprawl for sedimentary habitats

What has happened to coastal dunes in the last half century? A multitemporal coastal landscape analysis in Central Italy

Shoreline variability via empirical orthogonal function analysis: Part I temporal and spatial characteristics

Detailed topo-bathymetric levellings were performed biannually for four years at Victoria Beach (Cadiz, Spain) after a beach renourishment carried out in Spring 1991. The subsequent time series were analysed using the Empirical Orthogonal Functions (EOF) method. The evolution of some characteristic longshore contour lines, such as the Highest High Water Level and the Lowest Low Water Level, is studied. The mean coastal line is related to the first spatial EOF mode. Furthermore, an objective criterion for distinguishing between a generalised recession and cyclic accretion-erosion processes due to seasonal sea-swell changes is described, and a uniformly clockwise turn of the shoreline to minimise longshore transport is identified.

/pdf/evolution-of-longshore-beach-contour-lines-determined-by-e-o-swuoow5e0i.pdf

Evolution of longshore beach contour lines determined by E.O.F. method

Grain size is a fundamental property of sediments and is commonly used to describe sedimentary facies and classify sedimentary environments. Among the various conventional techniques utilized to determine grain-size frequency distributions, sieving is the most widely applied procedure. The accuracy of such analyses is, among other factors, strongly dependent on the sieving time. However, despite a substantial amount of research in this field, optimal sieving times for different types of sediments have, to date, not been established. In this article, the influence of sieving time on grain-size analyses of medium-grained microtidal and mesotidal beach and dune sands has been determined. To assess the precision of important textural parameters, such as median grain size, sorting, skewness and kurtosis, an error analysis was carried out for different sieving times (2, 5, 10, 15 and 20 minutes). After calibrating the analytical and sampling methodologies, significant deviations were registered when sieving time was less than 10 minutes. However, such deviations were very small and grain-size distributions remained almost identical for sieving times of 10 minutes and longer, relative errors being as low as 0% in some cases.

/pdf/influence-of-sieving-time-on-the-efficiency-and-accuracy-of-14hoa9zpwr.pdf

Influence of sieving time on the efficiency and accuracy of grain-size analysis of beach and dune sands

The study of recent sedimentation in the Gulf of Cadiz continental shelf (SW Europe) is of interest due to its proximity to the Strait of Gibraltar, where the Atlantic and Mediterranean waters are interchanged and the Western Mediterranean Alpidic Orogen closes through the Gibraltar Arch. The existence of relict materials hinders the distinction of the past and present hydrodynamic regimes in present day sediments. An adequate combination of techniques has allowed the establishment of the multicyclic character of the sediments, as well as the stages undergone by the terrigenous grains. Different stages were identified: eolian and energetic fluvial provenance, chemical alterations acquired in a pedological environment, and a marine coastal origin. To verify the source areas, textural and mineralogical features of marine sediments were compared with those found in geological units from fluvial basins. Three zones were differentiated: (a) a sandy littoral, which receives local sediment supplies; (b) a clayey zone between the Guadalquivir River and Cadiz, controlled by contributions from this river provenant of the Iberian Massif and Betic Mountain range; and (c) a sandy continental shelf, between Cadiz and the Cape of Trafalgar, with a low rate of supplies coming from the Guadalete and Barbate rivers, which include materials from the Occidental Betic Mountain range and Neogene units.

Multicycle sediments on the continental shelf of Cadiz (SW Spain)

https://rodin.uca.es/xmlui/bitstream/handle/10498/16140/Roman-Sierra%20et%20al.%202014.pdf;sequence=1

Juan J. Muñoz-Perez

Papers

Evolution of longshore beach contour lines determined by E.O.F. method

Influence of sieving time on the efficiency and accuracy of grain-size analysis of beach and dune sands

Multicycle sediments on the continental shelf of Cadiz (SW Spain)

Beach nourishment effects on sand porosity variability

Long-term evolution of a transgressive migrating dune using reconstruction of the EOF method