The highground: exploring landfill surface contouring for enhanced aesthetics in Southern California

Master of Landscape ArchitectureDepartment of Landscape Architecture/Regional and Community PlanningHoward D. HahnDaily waste production in the United States has steadily increased and follows population growth, especially in metropolitan areas and populated states. Since landfill permitting is typically a long and potentially controversial process, the trend is toward fewer but larger landfills. As a result, landfills near urban areas can be massive and are potentially seen by hundreds of thousands of people daily. Views of refuse being deposited is generally minimal, but as soil cover is incrementally added, the overall emerging landform is often visually incompatible with the surrounding topography. Many landfills tend to be geometrically shaped with angular faces, sharp corners, and mesa-like tops resulting in a flat ridgeline silhouette which can be recognized from great distances. Visual disruptions related to landfill operations can last for decades, and views after closure/restoration are permanent. This project and report explore to what degree landfills can be aesthetically contoured to more closely replicate contextual topography while maintaining high overall fill capacity. The study site is the Puente Hills landfill located in the urbanized Los Angeles basin. Additionally, 43 other landfills in Los Angeles County were inventoried to analyze geometric form and visual quality. From this group, three candidate landfills were selected for in-depth cross-sectional analysis. Extensive 3D modeling, using both manual and parametric methods, was then performed on the Puente Hills landfill to test various aesthetic “sculpting” scenarios. Corresponding volume capacity gains/losses were compared between enhanced landfill options and a landfill of standard configuration serving as the control. Findings attempt to show that enhanced landfill contouring is possible within acceptable engineering practices which could lead to easier landfill permitting by reducing visual impacts to the viewing public. This project and report also demonstrate how landscape architects can influence the aesthetic integrity of large landscapes that typically fall within the domain of civil engineers

Imagining Earth: Concepts of Wholeness in Cultural Constructions of Our Home Planet

While concepts of Earth have a rich tradition, more recent examples show a distinct quality: Though ideas of wholeness might still be related to mythical, religious, or utopian visions of the past, "Earth" itself has become available as a whole. This raises several questions: How are the notions of one Earth or our Planet imagined and distributed? What is the role of cultural imagination and practices of signification in the imagination of "the Earth"? Which theoretical models can be used or need to be developed to describe processes of imagining Planet Earth? This collection invites a wide range of perspectives from different fields of the Humanities to explore the means of imagining Earth

Imagining Earth

While concepts of Earth have a rich tradition, more recent examples show a distinct quality: Though ideas of wholeness might still be related to mythical, religious, or utopian visions of the past, ''Earth'' itself has become available as a whole. This raises several questions: How are the notions of one Earth or our Planet imagined and distributed? What is the role of cultural imagination and practices of signification in the imagination of ''the Earth''? Which theoretical models can be used or need to be developed to describe processes of imagining Planet Earth? This collection invites a wide range of perspectives from different fields of the Humanities to explore the means of imagining Earth

Advances in planetary geology

This second issue in a new series intended to serve the planetary geology community with a form for quick and thorough communications includes (1) a catalog of terrestrial craterform structures for northern Europe; (2) abstracts of results of the Planetary Geology Program, and (3) a list of the photographic holdings of regional planetary image facilities

Combinación de modelos anlíticos y analógicos de sistemas transpresivos con alto reparto de la deformación : la zona de Cizalla del Torcal (Béticas Externas)

Programa de Doctorado en Estudios MedioambientalesTranspressive high-strain zones are common features in the lateral parts of orogenic arcs where oblique convergence usually occurs. The strain within these zones is highly partitioned when they are located in the upper crust. In order to better understand the meaning of strain partitioning modes and strain localization within transpression shear zones, this thesis provides an exhaustive structural study of a natural case, based on surface structural data combined with analytical and analogue modelling. Thus, a protocol to test a general triclinic transpression model was applied to the so-called Torcal Shear Zone, a highly partitioned brittle-ductile shear zone located in the northern branch of the Gibraltar Arc. In addition, the theoretically obtained far-field parameters together with field data have provided the boundary conditions as well as the main parameters for designing the analogue models. It is noteworthy to mention that this work offers the first analogue model of oblique convergence that simulates triclinic inclined transpression. The combination of analytical and analogue models sheds some light on the deformation processes within the upper crustal transpression zones and, to a broader extend, high strain zones in general. Within the Gibraltar Arc, the Western Gibraltar Arc (WGA) is a protruded salient, 200 km in cord length, closely coinciding with the apex zone of the major arc. The TSZ is located in the External Zones (Subbetics) at the northeast termination of the WGA. The TSZ is a 70 km long and 4-5 km wide brittle-ductile deformation band that forms a W-E topographic alignment along which the kinematic data show an overall dextral transpression. Within the TSZ, strain is highly partitioned at multiples scales into mainly shortening, extensional and strike-slip structures. Regarding their structural associations, three distinctive zones can be defined within the TSZ: a) the central sector which comprises in turn two distinctive structural domains, the Valle de Abdalajís and the Torcal de Antequera massifs (VAM and TAM, respectively), b) the western end of the TSZ which coincides with the Teba-Peñarrubia massif, and c) the eastern end which corresponds to the Cabras- Camorolos sector. All these sectors show evidences of overall dextral transpression during the Late Miocene to the Quaternary. The application of a general analytical triclinic transpression model with oblique extrusion has been made by means of a standard procedure. This procedure comprises five consecutive steps, although some of them could be reordered, or even skipped, depending on the case. The results obtained for the central sector of the TSZ have permitted to estimate the orientation of the far-field velocity vector ((Fd) ¿) responsible for the TSZ bulk deformation. A single N99ºE-N109ºE trending horizontal velocity vector (V ¿) could explain the kinematics of the entire TSZ central sector. Additionally, our results suggest that the spatial distribution of the main structures observed in the central sector reflects different modes of strain partitioning and strain localization, which indicates that each massif accommodated a specific bulk strain. The partitioned flow in the TAM produces larger transpression obliquity and Wk values, with respect to the Valle de Abdalajís massif. The TAM shows a more complex strain partitioning situation with two narrow outer domains that accommodate simple shear- dominated dextral transpression, and a wider inner domain deformed by triclinic pure-shear-dominated transpression. In contrast, the VAM displays a typical discrete partitioning situation, with a discrete, simple shear, dextral strike-slip fault zone at the southern boundary; whereas the rest of the massif is affected by distributed deformation, whose bulk kinematics would approximate slightly triclinic (pseudo-monoclinic), pure-shear-dominated transpression. Such flow partitioning between these massifs appears to be mainly controlled by (1) slight, along strike variations in the orientation of the Alboran Domain - Subbetic unit boundary, (2) lateral differences in the thickness of the weak Triassic layer and (3) the rheological contrast related to the contact between limestones and marly limestones. Analogue modelling carried out to reproduce the structural pattern of the Torcal de Antequera massif was made by simulating triclinic transpression with two inclined parallel backstops in an oblique convergence setting. The oblique convergence angles used in experiments (15º and 30º) were chosen from analytical results to simulate the two differentiated structural domains within the TAM. Results support that: a) the structural style depends on the thickness variation in the ductile layer; b) planar boundaries favour the early nucleation of boundaries-parallel deformation zones where mainly strike-slip, simple shear deformation concentrates; c) different modes of strain partitioning and strain localization between the two different domains are related to different values of the oblique convergence angle: in 15º model strain partitioning is simple and strain localization is high, whereas in the pure-shear-dominated case (30º model) strain partitioning is strong (forming oblique-to-the walls thrusts and parallel-to-the walls strike-slip faults) and deformation spreads over a much wider area. The results concerning the structure and kinematics of the natural case show that the TSZ induces the near vertical extrusion of the Subbetic units and the dextral deflection of the regional structural trend-line pattern. This indicates the TSZ represents the main structure that shapes the northern end of the Western Gibraltar Arc salient. The structure and kinematics of the TSZ central sector are compatible with a single, Late Miocene to Quaternary, transpressional event. This event would be related to a unique velocity vector, whose orientation ranges from N99ºE to N109ºE. The different structural patterns exhibited by the two lateral domains make them comparable to splay-dominated (western end) and thrust-dominated (eastern end) strike-slip fault tips, where the most of the TSZ strike-slip displacement may be accommodated. This underlines the importance of the westward motion of the Alboran Domain relative to the external wedge and fits well with the radial outward thrusting pattern identified in the Western Gibraltar Arc. The identification of a variety of strain partitioning modes at multiple scales is revealed as an essential question to be taken into account in any kinematic model of the Gibraltar Arc system.Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturale