Despite a breadth of work investigating the spatiotemporal details of fluid dynamics over bedforms and bedload transport dynamics over flat beds, there remains a relative dearth of investigations into the spatiotemporal details of bedload transport over bedforms and on a sub-bedform scale. To address this, we conducted two sets of flume experiments focused on the two fundamental regions of flow associated with bedforms: flow separation/reattachment on the lee side of the bedform (Chapter 1; backward facing-step) and flow reacceleration up the stoss side of the next bedform (Chapter 2; two-dimensional bedform). Using Laser and Acoustic Doppler Velocimetry to record fluid turbulent events and manual particle tracking of high-speed imagery to record bedload transport dynamics, we identified the existence and importance of “permeable splat events” in the region proximal to flow reattachment.
These coupled turbulent and sediment transport events are integral to the spatiotemporal pattern of bedload transport over bedforms. Splat events are localized, high magnitude, intermittent flow features in which fluid impinges on the bed, infiltrates the top portion of bed, and then exfiltrates in all directions surrounding the point of impingement. This initiates bedload transport in a radial pattern. These turbulent structures are primarily associated with quadrant 1 and 4 turbulent structures (i.e. instantaneous fluid fluctuations in the streamwise direction that bring fluid down into the bed in the case of quadrant 1 events, or up away from the bed in the case of quadrant 4 events) and generate a distinct pattern of bedload transport compared to transport dynamics distal to flow reattachment. Distal to flow reattachment, bedload transport is characterized by relatively unidirectional transport. The dynamics of splat events, specifically their potential for inducing significant magnitudes of cross-stream transport, has important implications for the evolution of bedforms from simple, two dimensional features to complex, three-dimensional features.
New advancements in sonar technology have enabled more detailed quantification of bedload transport on the reach scale, a process paramount to the effective management of rivers with sand or gravel-dominated bed material. However, a practical and scalable field methodology for reliably estimating bedload remains elusive. A popular approach involves calculating transport from the geometry and celerity of migrating bedforms, extracted from time-series of bed elevation profiles (BEPs) acquired using echosounders. Using two sets of repeat multibeam sonar surveys from the Diamond Creek USGS gage station in Grand Canyon National Park with large spatio-temporal resolution and coverage, we compute bedload using three field techniques for acquiring BEPs: repeat multi-, single-, and multiple single-beam sonar. Significant differences in flux arise between repeat multibeam and single beam sonar. Mulitbeam and multiple single beam sonar systems can potentially yield comparable results, but the latter relies on knowledge of bedform geometries and flow that collectively inform optimal beam spacing and sampling rate. These results serve to guide design of optimal sampling, and for comparing transport estimates from different sonar configurations.
Human-environment interactions in aeolian (windblown) systems has focused research on<br/>human’s role in causing and aiding recovery from natural and anthropogenic disturbance. There<br/>is room for improvement in understanding the best methods and considerations for manual<br/>coastal foredune restoration. Furthermore, the extent to which humans play a role in changing the<br/>shape and surface textures of quartz sand grains is poorly understood. The goal of this thesis is<br/>two-fold: 1) quantify the geomorphic effectiveness of a multi-year manually rebuilt foredune and<br/>2) compare the shapes and microtextures on disturbed and undisturbed quartz sand grains. For<br/>the rebuilt foredune, uncrewed aerial systems (UAS) were used to survey the site, collecting<br/>photos to create digital surface models (DSMs). These DSMs were compared at discrete<br/>moments in time to create a sediment budget. Water levels and cross-shore modeling is also<br/>considered to predict the decadal evolution of the site. In the two years since rebuilding, the<br/>foredune has been stable, but not geomorphically resilient. Modeling shows landward foredune<br/>retreat and beach widening. For the quartz grains, t-testing of shape characteristics showed that<br/>there may be differences in the mean circularity between grains from off-highway vehicle and<br/>non-riding areas. Quartz grains from a variety of coastal and inland dunes were imaged using a<br/>scanning electron microscopy to search for evidence of anthropogenically-induced<br/>microtextures. On grains from Oceano Dunes in California, encouraging textures like parallel<br/>striations, grain fracturing, and linear conchoidal fractures provide exploratory evidence of<br/>anthropogenic microtextures. More focused research is recommended to confirm this exploratory<br/>work.
The Journal of Surrealism and the Americas: Vol. 2 No. 2 (2008) - Table of Contents
“Surrealism and Photography: Introduction” by Wendy Grossman, p. i-iv.
“‘Surrealistic and disturbing’: Timothy O’Sullivan as Seen by Ansel Adams in the 1930s” by Britt Salvesen, p. 162-179.
“‘As if one’s eyelids had been cut away’: Frederick Sommer’s Arizona Landscapes” by Ian Walker, p. 180-208.
“Clarence John Laughlin, Regionalist Surrealist” by Lewis Kachur, p. 209-226.
“A Swimmer Between Two Worlds: Francesca Woodman’s Maps of Interior Space” by Katharine Conley, p. 227-252.
“Remembering Anne D’Harnoncourt” by Valery Oisteanu, p. 253.
“The 1930s: The Making of the ‘New Man’” by Julia Pine, p. 254-258.
“Beyond Bridges: The Cinema of Jean Rouch” by Robert McNab, p. 259-262.
“Review of Kirby Olson, ‘Andrei Codrescu and the Myth of America’” by Éva Forgács, p. 263-267.
“Review of Sally Price, 'Paris Primitive: Jacques Chirac’s Museum on the Quai Branly’” by Kate Duncan, p. 268-272.
The Journal of Surrealism and the Americas: Vol. 8 No. 1 (2014) - Table of Contents
“Manuel Álvarez Bravo: Surrealism and Documentary Photography” by Ian Walker, p. 1-27.
“(Sur)real or Unreal?: Antonin Artaud in the Sierra Tarahumara of Mexico” by Lars Krutak, p. 28-50.
“Surrealist Views, American Landscapes: Notes on Wolfgang Paalen’s Ruin Gazing” by Kent L. Dickson, p. 51-73.
“‘Don’t Forget I Come From the Tropics’: Reconsidering the Surrealist Sculpture of Maria Martins” by Michael R. Taylor, p. 74-89.
“‘Le centre du milieu’: Matta and the Exploding Dome” by Denise Birkhofer, p. 90-104.
“Edward James and Plutarco Gastélum in Xilita: Critical Paranoia in the Mexican Jungle” by Irene Herner, p. 105-123.
“Review of Ellen Landau, ‘Mexico and American Modernism’” by Luis M. Castañeda, p. 124-126.
“‘Surrealist Ghosts and Spectrality in Surrealist Ghostliness’ by Katharine Conley” by Martine Antle, p. 127-129.
“Review of Roger Rothman, ‘Tiny Surrealism: Salvador Dalí and the Aesthetics of the Small’” by Jonathan S. Wallis, p. 130-135.
“Review of ‘Late Surrealism’: The Menil Collection, May 24- August 25, 2013” by Rachel Hooper, p. 136-139.
When André Breton went to Mexico in 1938, he saw the photographs of Manuel Álvarez Bravo, took a set of them back with him to France and, the following year, published and exhibited them as part of his espousal of Mexico as “the surrealistic place par excellence.” That is the first reason why the work of Álvarez Bravo cannot be overlooked in the broader context of Surrealism. This circumstance, often cited, has rarely been analyzed in any depth and part of the aim of this essay is to undertake that analysis.
Antonin Artaud was one of the first internationally recognized writers to introduce the indigenous Tarahumara (Rarámuri) of Northwest Mexico to the world. In a series of publications based on his experiences with the tribe in 1936, Artaud left a vast visual legacy that positioned the Tarahumara within a powerful regime of representation, one that framed them within a mixed landscape of exoticism, primitivism, and peyote-inspired mysticism. This paper focuses on these literary works and interrogates the veracity of Artaud’s experiences and observations among the “pure race.” Drawing on the ethnographic record of the twentieth century and anthropological field research, it is my intention to reveal Artaud’s ability to fabricate, exaggerate, and embellish “the truth” which he so desperately desired to understand.
In New York in 1944, the Surrealist magazine VVV published two photographs of the Arizona desert by Frederick Sommer. They are radical images in their minimalism and intensity of attention to (apparently) very little.
Sommer’s immediate connection was with Max Ernst, who saw these pictures when he visited Arizona in 1943. Later, when Ernst came to live at Sedona, the two men influenced each other’s work. Yves Tanguy also visited in 1951 and J. T. Soby suggested that the ‘breathless congestion of boulders, pebbles and bones’ in Tanguy’s last paintings derive from his experience of the desert as viewed through Sommer’s photographs.
Even in Europe, where Surrealism was predominantly urban, there had been an interest in the extreme landscapes of desert or jungle. But while Salvador Dali transformed rock forms into bodies, the challenge of the desert as Sommer depicted it was that no such transformation was possible. In addition, there was a Surrealist fascination with the "terrain vague"—land which is formless, void of composition—and it would be intriguing to extend the idea to Sommer’s desert pictures, which equally irritate the eye with their apparent lack of organization and focus.
It was Sommer’s meeting with Edward Weston that led to his use of a 10 x 8” camera to create the intensity of these pictures. But Sommer’s sense of the violence of the desert was at odds with the positive way it was depicted by Weston or Ansel Adams and his work was written out of photographic history for a long time. It’s no accident that it was rediscovered in the 1970s, when the myth of the American West was subjected to a severe critique and it’s intriguing to also place Sommer’s photographs in a lineage that goes back to Timothy O’Sullivan and forward to Richard Misrach.
Sommer’s work stands then at the intersection between the photography of the American West and Surrealism - between Edward Weston and Max Ernst. But it is also quite unlike either and, in their unflinching gaze at a subject that is both intense and empty, Sommer’s Arizona Landscapes profoundly undermine the conventions of vision.