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Description
The San Andreas Fault (SAF) is the primary structure within a system of faults accommodating motion between the North American and Pacific plates. Physical models of faulting and characterizations of seismic hazard are informed by investigations of paleoseismology, slip distribution, and slip rate. The impact of earthquakes on people is due in large part to social vulnerability. This dissertation contributes an analysis about the relationships between earthquake hazard and social vulnerability in Los Angeles, CA and investigations of paleoseismology and fault scarp array complexity on the central SAF. Analysis of fault scarp array geometry and morphology using 0.5 m digital elevation models along 122 km of the central SAF reveals significant variation in the complexity of SAF structure. Scarp trace complexity is measured by scarp separation, changes in strike, fault trace gaps, and scarp length per SAF kilometer. Geometrical complexity in fault scarp arrays indicates that the central SAF can be grouped into seven segments. Segment boundaries are controlled by interactions with subsidiary faults. Investigation of an offset channel at Parkfield, CA yields a late Holocene slip rate of 26.2 +6.4/- 4.3 mm/yr. This rate is lower than geologic measurements on the Carrizo section of the SAF and rates implied by far-field geodesy. However, it is consistent with historical observations of slip at Parkfield. Paleoseismology at Parkfield indicates that large earthquakes are absent from the stratigraphic record for at least a millennia. Together these observations imply that the amount of plate boundary slip accommodated by the main SAF varies along strike. Contrary to most environmental justice analyses showing that vulnerable populations are spatially-tied to environmental hazards, geospatial analyses relating social vulnerability and earthquake hazard in southern California show that these groups are not disproportionately exposed to the areas of greatest hazard. Instead, park and green space is linked to earthquake hazard through fault zone regulation. In Los Angeles, a parks poor city, the distribution of social vulnerability is strongly tied to a lack of park space. Thus, people with access to financial and political resources strive to live in neighborhoods with parks, even in the face of forewarned risk.
ContributorsToké, Nathan A (Author) / Arrowsmith, J R (Thesis advisor) / Boone, Christopher G (Committee member) / Heimsath, Arjun M (Committee member) / Shock, Everett L (Committee member) / Whipple, Kelin X (Committee member) / Arizona State University (Publisher)
Created2011
Description
Sedimentary basins in the Afar Depression, Ethiopia archive the progression of continental breakup, record regional changes in east African climate and volcanism, and host what are arguably the most important fossiliferous strata for studying early human evolution and innovation. Significant changes in rift tectonics, climate, and faunal assemblages occur between 3-2.5 million years ago (Ma), but sediments spanning this time period are sparse. In this dissertation, I present the results of a geologic investigation targeting sediments between 3-2.5 Ma in the central and eastern Ledi Geraru (CLG and ELG) field areas in the lower Awash Valley, using a combination of geologic mapping, stratigraphy, and tephra chemistry and dating. At Gulfaytu in CLG, I mapped the northern-most outcrops of the hominin-bearing Hadar Formation (3.8-2.9 Ma), a 20 m-thick section of flat-lying lacustrine sediments containing 8 new tephras that directly overlie the widespread BKT-2 marker beds (2.95 Ma). Paleolake Hadar persisted after 2.95 Ma, and the presence and characteristics of the Busidima Formation (2.7-0.016 Ma) indicates Gulfaytu was affected by a reversal in depositional basin polarity. Combined with regional and geophysical data, I show the Hadar Formation underlying CLG is >300 m thick, supporting the hypothesis that it was the lower Awash Pliocene depocenter. At ELG, I mapped >300 m of sediments spanning 3.0-2.45 Ma. These sediments coarsen upward and show a progression from fluctuating lake conditions to fluvial landscapes and widespread soil development. This is consistent with the temporal change in depositional environments observed elsewhere in the lower Awash Valley, and suggests that these strata are correlative with the Hadar Formation. Furthermore, the strata and basalts at ELG are highly faulted, and overprinted by shifting extension directions attributed to the northern migration of the Afar triple junction. The presence of fossiliferous beds and stone tools makes ELG a high-priority target for anthropological and archaeological research. This study provides a new temporally-calibrated and high-resolution record of deposition, volcanism, and faulting patterns during a period of significant change in the Afar.
ContributorsDiMaggio, Erin Nicole (Author) / Arrowsmith, J Ramon (Thesis advisor) / Whipple, Kelin X (Committee member) / Heimsath, Arjun M (Committee member) / Clarke, Amanda B (Committee member) / Reed, Kaye E (Committee member) / Arizona State University (Publisher)
Created2013
Description
The ability of Neandertals to cope with the oscillating climate of the late Pleistocene and the extent to which these climate changes affected local Neandertal habitats remain unanswered anthropological topics of considerable scientific interest. Understanding the impact of climatic instability on Neandertals is critical for reconstructing the behaviors of our closest fossil relatives and possibly identifying factors that contributed to their extinction. My work aimed to test the hypotheses that 1) cold climates stressed Neandertal populations, and 2) that global climate changes affected local Neandertal habitats. An analysis of Neandertal butchering on Cervus elaphus, Rangifer tarandus, and Capreolus capreolus skeletal material deposited during global warm and cold phases from two French sites - Pech de l'Azé IV and Roc de Marsal - was conducted to assess the impact of climate change on butchering strategies and resource extraction. Results from a statistical analysis of surface modification on all marrow yielding long bones, including the 1st phalanx, demonstrated that specimens excavated from the cold levels at each cave have more cut marks (Wald χ2= 51.33, p= <0.001) and percussion marks (Wald χ2= 4.92, p= 0.02) than specimens from the warm levels after controlling for fragment size. These results support the hypothesis that Neandertals were nutritionally stressed during glacial cycles. The hypothesis that global climates affected local habitats was tested through radiogenic strontium isotopic reconstruction of large herbivore mobility patterns (e.g., Bison, Equus, Cervus and Rangifer), because it is known that in the northern hemisphere, mammals migrate less in warm, well-vegetated environments, but more in cold, open environments. Identifying isotopic variation in mammalian fossils enables mobility patterns to be inferred, providing an indication of whether environments at Pech de l'Azé IV and Roc de Marsal tracked global climates. Results from this study indicate that Neandertal prey species within the Dordogne Valley of France did not undertake long distance round-trip migrations in glacial or interglacial cycles, maintaining the possibility that local habitats did not change in differing climatic cycles. However, because Neandertals were nutritionally stressed the most likely conclusion is that glacial cycles decreased herbivore populations, thus stressing Neandertals.
ContributorsHodgkins, Jamie Melichar (Author) / Marean, Curtis W (Thesis advisor) / Reed, Kaye E (Thesis advisor) / Knudson, Kelly J. (Committee member) / Spencer, Lillian M (Committee member) / Arizona State University (Publisher)
Created2012
Description
Identifying the ecological role, or niche, that a species occupies within their larger community elucidates environmental adaptability and evolutionary success. This dissertation investigates the occupied niche of chimpanzees (Pan troglodytes schweinfurthii) living in an open, dry savanna-woodland environment by examining patterns of resource use and interspecific interactions. Data were collected October 2010--November 2011 at Issa, in the Ugalla region of western Tanzania, which is one of the driest, most open, and seasonal habitats inhabited by chimpanzees. Unlike most primatological studies which employ methods that include focal follows, this study focused instead on observing 'resource patches' for chimpanzees. Patch focals allow for the observation of all animals within a study area; capture resources that are not used by the study species; and are particularly well suited for unhabituated communities. In order to better understand relationships between environment and behavior, data collected at Issa are compared with published data from other chimpanzee populations. Issa chimpanzees were expected to have broader resource use than forest chimpanzees, as well as increased competition with other fauna, due to fewer available resources. However, in contrast to the assumption of food scarcity in dry habitats, dietary resources were available throughout the year. Like other populations, the diet of Issa chimpanzees consisted of mostly fruit, but unlike at other sites, the majority of plants consumed were woodland species. Additionally, although chimpanzees and other fauna shared spatial and dietary resources, there was only nominal overlap. These results point to extremely low levels of indirect competition between chimpanzees and other fauna. Despite extensive study of forest chimpanzees, little is known about their role within their faunal community in open, dry habitats, nor about how greater seasonality affects resource use. This project addresses both of these important issues and fosters novel approaches in anthropological studies, especially in reference to chimpanzee ecology and evolution. Understanding current chimpanzee behavioral relationships with their environments shapes hypotheses about their pasts, and also informs predictions about behaviors of similar taxa in paleo-environments. Lastly, examining the ecological role of chimpanzees within their larger communities will influence the formation of, as well as evaluate, conservation strategies.
ContributorsRussak, Samantha M (Author) / Reed, Kaye E (Thesis advisor) / Nash, Leanne T. (Committee member) / Schwartz, Gary T (Committee member) / Arizona State University (Publisher)
Created2013
Description
Unanswered questions about the evolution of human gender abound and are salient across the anthropological disciplines and beyond. Did adult sex-typed behavioral tendencies actually evolve? If so, when? For what purpose? The best way to gain insight into the evolution of human gender is to understand the evolution and development of sex-typed behavior in comparative primate taxa. Captive research indicates that there are many proximate factors likely to shape the development of sex-typed behavior in non-human primates—prenatal and postnatal endocrinological experience, social experience, ecological factors, and their interactions. However, it is largely unknown how sex-typed behavior proceeds and is shaped by those factors in evolutionarily salient environments. This study investigated one—whether extrinsic sexually differentiated social interactions are likely influential in the development of adult sex-typed behavior in wild-living Lemur catta. Little is known about sex-typed development in this species or in strepsirrhines in general. This research therefore addresses an important phylogenetic gap in our understanding of primate sex-typed development. Behavioral observations were carried out on mixed cross-sectional sample of adult females (n=10), adult males (n=8), yearling females (n=4), yearling males (n=4), and newborn females (n=16) and males (n=14) at Beza Mahafaly Special Reserve in southwest Madagascar from September 2008 to August 2009. Twenty-three sex-typed behaviors were identified in adults using linear mixed effects models and models of group response profiles through time. Of those, only eight had a pre-pubertal developmental component. Infants did not exhibit any sex differences in behavior, but juveniles (prepubertal, weaned individuals) resembled adults in their (relatively few) patterns of expression of sex-typed behavior. Most adult sex-typed behaviors in this species apparently develop at or after puberty and may be under gonadal hormone control. Those that develop before puberty do not likely depend on extrinsic sexually differentiation social interactions for their development, because there is no clear evidence that infants and juvenile male and females are not treated differently by others according to sex. If sexually differentiated social interactions are important for sex-typed behavioral development in subadult ,italic>Lemur catta, they are likely intrinsically (rather than extrinsically) driven.
ContributorsMeredith, Stephanie Lynn (Author) / Nash, Leanne T. (Thesis advisor) / Reed, Kaye E (Committee member) / Schwartz, Gary T (Committee member) / Arizona State University (Publisher)
Created2012
Description
Fundamental hypotheses about the life history, complex cognition and social dynamics of humans are rooted in feeding ecology - particularly in the experiences of young animals as they grow. However, the few existing primate developmental data are limited to only a handful of species of monkeys and apes. Without comparative data from more basal primates, such as lemurs, we are limited in the scope of our understanding of how feeding has shaped the evolution of these extraordinary aspects of primate biology. I present a developmental view of feeding ecology in the ring-tailed lemur (Lemur catta) using a mixed longitudinal sample (infant through adult) collected at the Beza Mahafaly Special Reserve in southwestern Madagascar from May 2009 to March 2010. I document the development of feeding, including weaning, the transition to solid food, and how foods are included in infant diets. Early in juvenility ring-tailed lemurs efficiently process most foods, but that hard ripe fruits and insects require more time to master. Infants and juveniles do not use many of the social learning behaviors that are common in monkeys and apes, and instead likely rely both on their own trial and error and simple local enhancement to learn appropriate foods. Juvenile ring-tailed lemurs are competent and efficient foragers, and that mitigating ecological risks may not best predict the lemur juvenile period, and that increases in social complexity and brain size may be at the root of primate juvenility. Finally, from juvenility through adulthood, females have more diverse diets than males. The early emergence of sex differences in dietary diversity in juvenility that are maintained throughout adulthood indicate that, in addition to reproductive costs incurred by females, niche partitioning is an important aspect of sex differential feeding ecology, and that ontogenetic studies of feeding are particularly valuable to understanding how selection shapes adult, species-typical diets. Overall, lemur juvenility is a time to play, build social relationships, learn about food, and where the kernels of sex-typical feeding develop. This study of the ontogeny of feeding ecology contributes an important phylogenetic perspective on the relationship between juvenility and the emergent foraging behaviors of developing animals
ContributorsO'Mara, Michael Teague (Author) / Nash, Leanne T. (Thesis advisor) / Reed, Kaye E (Committee member) / Schwartz, Gary T (Committee member) / Sauther, Michelle L (Committee member) / Arizona State University (Publisher)
Created2012
Description
The bony pelvis is a pivotal component of the locomotor system, as it links the hindlimb with the trunk and serves as anchorage for the primary propulsive musculature. Its shape is therefore expected to be adapted to the biomechanical demands of habitual locomotor behavior. However, because the relationship between locomotor mechanics and pelvic morphology is not well understood, the adaptive significance of particular pelvic traits and overall pelvic shape remains unclear. This study used an integrative, dual approach to elucidate the relationship between form and function in the primate pelvis. A biomechanical cylinder model of pelvic stress resistance was tested using in vitro strain analysis of monkey and ape cadaver specimens. These results were used to refine adaptive hypotheses relating pelvic form to locomotor mechanics. Hypotheses of adaptation were then tested via univariate and geometric morphometric methods using a taxonomically broad, comparative sample of 67 primate taxa. These results suggest that the pelvis exhibits some iliac and ischial adaptations to stress resistance that are associated with the biomechanical demands of habitual locomotor loading and of body size. The ilium and ischium exhibit relatively low levels of strain during experimental loading as well as adaptations that increase strength. The pubis exhibits relatively high strains during loading and does not vary as predicted with locomotion. This integrated study clarifies the relationship between strain and adaptation; these results support the hypothesis that bones adapted to stress resistance exhibit low strains during typical loading. In general, the cylinder model of pelvic biomechanics is unsupported. While the predictions of loading regimes were generally rejected, the inability of these methods to test the possible occurrence of overlapping loading regimes precludes outright rejection of the cylinder model. However, the lack of support for predicted global responses to applied loading regimes suggests that pelvic stress resistance may be better explained by a model that accounts for local, functional subunits of pelvic structure. The coalescence of a localized model of pelvic biomechanics and comparative morphometrics has great potential to shed light on the evolution of the complex, multi-functional structure of the pelvis.
ContributorsLewton, Kristi Lynn (Author) / Spencer, Mark A. (Thesis advisor) / Reed, Kaye E (Committee member) / Schwartz, Gary T (Committee member) / Ward, Carol V. (Committee member) / Arizona State University (Publisher)
Created2010
Description
Anthropogenic activities have had a profound effect on ecosystems, sediment budgets, and dust emissions stemming from widespread changes in land use and land cover and increases in sediment disturbance. Sandy coastal environments are under increasing pressure from the impacts of rising sea levels, coastal flooding, and erosion. Coastal foredunes can serve as a buffer to protect coastal communities from the impacts of coastal erosion, flooding, and sea-level rise. They also serve an important role as an ecosystem service, providing opportunities for recreation (off-highway vehicle, hiking, tourism) and habitat for native and endemic biota. Increased disturbance and pressure by human activity within the beach-dune system can lead to a decoupling of form and function from natural geomorphic and biotic processes. Dune management and restoration is often employed to mitigate some of the aforementioned pressures. Dynamic or ‘nature-based’ restoration aims to restore the form and function of a geomorphic system and improve landform resilience to external pressures by employing complimentary native plant species. This type of approach places emphasis on the ecological and geomorphic interactions within a landscape to improve the overall function and resiliency of the system to external pressures. Two case studies along the coast of California, the Lanphere Dunes and Oceano Dunes, provide uniquely different approaches to foredune restoration and the corresponding issues of landscape management for various goals. The case studies provided employ a suite of close-range remote sensing techniques, including kite aerial photography, uncrewed aerial systems photography, and terrestrial laser scanning, to generate high resolution (< 0.1 m) products (surface models; orthophoto mosaics in red-green-blue (RGB) and multispectral) to quantify and inform on restoration efforts by examining sediment budget and vegetation characteristics over a mesoscale (spatial and temporal). Results were compared to a variety of control sites (e.g., no restoration, natively vegetated, invasively vegetated) to highlight the differences between restored and unrestored landscapes, and the efficacy of restoration efforts for improving the developmental trajectory of a landscape towards a "desired" state.
ContributorsHilgendorf, Zach (Author) / Walker, Ian J (Thesis advisor) / Dorn, Ronald I (Committee member) / Schmeeckle, Mark W (Committee member) / Arizona State University (Publisher)
Created2022
Description
Increasing rates of sea-level rise (SLR) pose a major threat to coastal communities around the world. Evidence of these impacts is found in increased rates of extreme weather, erosion, coastal flooding, high water levels and wave height, altered geomorphology, and more. Coastal dunes act as a buffer for neighboring ecosystems and protect inland communities from increased rates of SLR. The Eureka Littoral Cell (ELC) in Humboldt County, California, which extends from Trinidad Head in the north to Cape Mendocino in the south, experiences extreme wave conditions and higher rates of SLR in comparison to the rest of the Pacific Northwest. This study focuses on assessing the vulnerability of the outer-barrier system of the ELC to SLR and complements previous vulnerability assessments of the inner Humboldt Bay. The study area was partitioned into thirteen (13) representative study reaches based on shoreline change rates and geomorphology. Twenty-two (22) environmental and socio-economic variables were identified to characterize the broader human-environmental connections and exposures that define coastal vulnerability beyond basic physical forcing and exposures. The study first compiled and examined a range of physical, biological, hazardous, socio-cultural, and infrastructure attributes of the outer barrier region of the study site for their inherent vulnerabilities. Second, individual vulnerability scores, based on geographic attributes of each variable, were determined by modifying existing methodologies (e.g., USGS), spanning variable data ranges, and/or with feedback from local representatives and a research advisory team. Aggregations of individual variables were used to provide variable category groupings (e.g., physical, biological, hazards, socio-cultural, and infrastructure). Finally, aggregated values were normalized on a one-to-ten scale to determine two sub-categories of vulnerability (environmental, socio-economic) and an overall comprehensive vulnerability for each study reach. The resulting vulnerability assessments identify which reaches are likely to experience low, moderate, and high levels of vulnerability and, based on variable and sub-grouping values, what factors contribute to this vulnerability. As such, this study addresses the significance of including both environmental and socio-economic variables to examine and characterize vulnerability to SLR and it is anticipated that the results will help inform future adaptation and resilience planning in the region.
ContributorsShinsato, Lara Miyori (Author) / Dorn, Ron I (Thesis advisor) / Walker, Ian J (Thesis advisor) / Schmeeckle, Mark (Committee member) / Arizona State University (Publisher)
Created2023
Description
Cercopithecid primates today occupy the greatest geographic and climatic range of any non-human primate group. Pliocene and Pleistocene cercopithecids are often found together in fossil deposits across East and South Africa, raising the question of how these species co-occurred with one another and survived in increasingly arid and seasonal environments. Aspects of shearing ability, molar enamel thickness, and relative incisor, premolar, and molar proportions were analyzed in principal component analysis and used to generate six potential models of the cercopithecid dental morphological niche. Resulting principal component axes distinguish between taxa with varying proportions of leaves, fruit, insects, and seeds in the diet, but lose some clarity when variable subsets are used that exclude poorly-preserved or wear-restricted variables. Resampling was used to reconstruct the aggregate dental morphological niches of cercopithecid communities (taxocenes) from Africa and Asia today and from the African Pliocene and Pleistocene. Modern Asian cercopithecid taxocenes occupy a more restricted niche than their counterparts in Africa, but in both regions variation in taxocene structure is linked with past and current climate factors related to precipitation, temperature, and seasonality. Fossil cercopithecids from the Turkana Basin occupy an expanded niche in comparison to modern African and Asian taxocenes. In contrast, South African fossil taxocenes occupy a more distinct and restricted niche, which may reflect a mix of paleoenvironmental and taphonomic factors. Overall these results are consistent with existing research on modern African and Asian primate taxocene diversity and highlight the utility of a dental metric model for examining community evolution among Plio-Pleistocene cercopithecids in Africa. Evidence for a possible niche expansion during the early Pleistocene coincides with a period of well-documented hominin co-occurrence at the same fossil sites, suggesting that these two primate groups were diversifying in response to shared environmental stimuli.
ContributorsSmail, Irene (Author) / Reed, Kaye E (Thesis advisor) / Campisano, Christopher J (Committee member) / Gilbert, Christopher C (Committee member) / Arizona State University (Publisher)
Created2021