title: Observations of wave energy fluxes and swash motions on a low-sloping, dissipative beach

authors: Guedes, Rafael M. C.

subjects: swash

abstract: Field observations of swash and ocean waves show that runup saturation at infragravity frequencies (<0.05 Hz) can occur under mild offshore energy conditions if the beach slope is sufficiently gentle. Infragravity saturation was observed for higher-frequency (>0.025–0.035 Hz) infragravity waves, where typically less than 5% of the (linear) energy flux was reflected from the beach and where, similar to the sea swell band, the swash energy was independent of offshore wave energy. The infragravity frequency range of saturation was determined by the tide, with saturation extending to lower frequencies at low tide when the local beach face slope over the concave-shaped profile was gentler. Runup was strongly dominated by infragravity frequencies, which accounted on average for 96% of the runup variance, and its energy levels were entirely consistent with strong infragravity wave dissipation observed in the surfzone, particularly when including the nonlinear contributions to the wave energy fluxes. The infragravity wave dissipation was strongly associated with breaking of sea swell waves, which abruptly decreased nonlinear transfers to infragravity frequencies and made infragravity dissipation prevail over forcing within the breaking region. Our observations show evidence of nonlinear interactions involving infragravity and high-frequency, harmonic waves and suggest that these harmonics could play a role in the wave energy balance near the shoreline on low-sloping, dissipative beaches.

text: Observations of wave energy fluxes and swash motions on a low-sloping, dissipative beach Field observations of swash and ocean waves show that runup saturation at infragravity frequencies (<0.05 Hz) can occur under mild offshore energy conditions if the beach slope is sufficiently gentle. Infragravity saturation was observed for higher-frequency (>0.025–0.035 Hz) infragravity waves, where typically less than 5% of the (linear) energy flux was reflected from the beach and where, similar to the sea swell band, the swash energy was independent of offshore wave energy. The infragravity frequency range of saturation was determined by the tide, with saturation extending to lower frequencies at low tide when the local beach face slope over the concave-shaped profile was gentler. Runup was strongly dominated by infragravity frequencies, which accounted on average for 96% of the runup variance, and its energy levels were entirely consistent with strong infragravity wave dissipation observed in the surfzone, particularly when including the nonlinear contributions to the wave energy fluxes. The infragravity wave dissipation was strongly associated with breaking of sea swell waves, which abruptly decreased nonlinear transfers to infragravity frequencies and made infragravity dissipation prevail over forcing within the breaking region. Our observations show evidence of nonlinear interactions involving infragravity and high-frequency, harmonic waves and suggest that these harmonics could play a role in the wave energy balance near the shoreline on low-sloping, dissipative beaches.

year: 2013-07

title: 'Not too calm'

authors: Lodge, Martin

abstract: At the time of his death in September 1999, music historian John Mansfield Thomson left a number of projects unfinished. One of these projects was an autobiography. In the course of my duties as executor of his literary estate, I subsequently discovered the beginnings of autobiographical writing on John's computer hard drive, and it was possible to include these fragments in the 2003 book John Mansfield Thomson: Notes towards a biography'.

text: 'Not too calm' At the time of his death in September 1999, music historian John Mansfield Thomson left a number of projects unfinished. One of these projects was an autobiography. In the course of my duties as executor of his literary estate, I subsequently discovered the beginnings of autobiographical writing on John's computer hard drive, and it was possible to include these fragments in the 2003 book John Mansfield Thomson: Notes towards a biography'.

year: 2005

title: Place imaginaries: Photography and place-making at Te Awa River Ride

authors: Hill, Rodrigo

subjects: photography

abstract: Contemporary photographic practice has evolved into a field of possibilities, which includes a flux of representational modes that depict experiences, feelings and emotions. This PhD with Creative Practice Components investigates how photography is embedded within ways of knowing, experiencing and making places and the subsequent visual constructions of place imaginaries.  Drawing on contemporary photographic practice and theory, I position myself as a qualitative researcher engaged in creative practice, specifically lens-based approaches and modes of photographic representation. In contrast to photography’s dominant discourse centred on indexical and objective assumptions, I understand photographic practices and images as constructions of multiple meanings.

I use Te Awa River Ride as my research locale, a place where different practices and discourses entangle, forming a diverse set of dynamic and intersecting meanings. Te Awa River Ride is a shared pathway, with a planned total length of 70 kilometres, that edges the banks of the Waikato River from Ngāruawāhia to Cambridge, in the central North Island of Aotearoa New Zealand. I understand Te Awa River Ride as a place-composite, layered by multiple place imaginaries, including indigenous Māori, Pākehā and European ways of meaning and place-making. In this thesis I draw upon place imaginaries as a way of expressing visual possibilities, constructions and affective responses to my own and others’ experiences at this unique research location. 

My photography practice aims to actualise particular place imaginaries through curation and sequencing of lens-based explorations of light, movement and water. This process and the compilation of imagery into curatorial products, such as photography installations, generate novel ways of perceiving the Waikato River and Te Awa River Ride, revealing the centrality of photography in place-making processes.

text: Place imaginaries: Photography and place-making at Te Awa River Ride Contemporary photographic practice has evolved into a field of possibilities, which includes a flux of representational modes that depict experiences, feelings and emotions. This PhD with Creative Practice Components investigates how photography is embedded within ways of knowing, experiencing and making places and the subsequent visual constructions of place imaginaries.  Drawing on contemporary photographic practice and theory, I position myself as a qualitative researcher engaged in creative practice, specifically lens-based approaches and modes of photographic representation. In contrast to photography’s dominant discourse centred on indexical and objective assumptions, I understand photographic practices and images as constructions of multiple meanings.

I use Te Awa River Ride as my research locale, a place where different practices and discourses entangle, forming a diverse set of dynamic and intersecting meanings. Te Awa River Ride is a shared pathway, with a planned total length of 70 kilometres, that edges the banks of the Waikato River from Ngāruawāhia to Cambridge, in the central North Island of Aotearoa New Zealand. I understand Te Awa River Ride as a place-composite, layered by multiple place imaginaries, including indigenous Māori, Pākehā and European ways of meaning and place-making. In this thesis I draw upon place imaginaries as a way of expressing visual possibilities, constructions and affective responses to my own and others’ experiences at this unique research location. 

My photography practice aims to actualise particular place imaginaries through curation and sequencing of lens-based explorations of light, movement and water. This process and the compilation of imagery into curatorial products, such as photography installations, generate novel ways of perceiving the Waikato River and Te Awa River Ride, revealing the centrality of photography in place-making processes.

year: 2019