Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 203-213).

Thesis (Ph.D.)--Lehigh University, 2000. / Source: Dissertation Abstracts International, Volume: 60-12, Section: B, page: 6187. Adviser: Yong W. Kim.

Thesis (M.S.)--Oregon State University, 1982. / Typescript (photocopy). Some maps folded in pocket. Includes bibliographical references (leaves 156-169). Also available via the World Wide Web.

Thesis (M.S.)--Brigham Young University. Dept. of Geology, 2003. / Includes bibliographical references (p. 38-40).

Oceanic island volcanoes such as those in the Hawaiian, Canary and Galapagos Islands are known to become unstable, causing failures of the subaerial and submarine slopes of the volcanic edifices. These mass wasting events appear to be the primary source of destruction and loss of volume of many oceanic islands, but our knowledge of mass wasting is still rudimentary in many seamount and island chains. To better understand mass wasting in the western Galapagos Islands, multi-beam bathymetry and backscatter sidescan sonar images were used to examine topography and acoustic backscatter signatures that are characteristic of mass wasting. Observations show that mass wasting plays an important role in the development of Galapagos volcanoes. While volcanic activity continues to conceal the submarine terrain, the data show that four forms of mass wasting are identified including debris flows, slumps sheets, chaotic slumps, and detached blocks. A total of 23 mass wasting features were found to exist in the western Galapagos Islands, including fourteen debris flows with one that incorporated a set of detached blocks, seven slump sheets, and one chaotic slump. Some of the indentified features have obvious origination zones while the sources of others are not clearly identifiable. Approximately 73 percent of the surveyed coastlines are affected by slumping on the steep upper slopes and ~64 percent are affected by debris flows on the lower slopes. Unlike the giant landslides documented by GLORIA imagery around the Hawaiian Islands, the western Galapagos Islands appear to be characterized by small slump sheets existing along the steep shallow submarine flanks of the island and by debris flows that are flanked by rift zones and extend off the platform. This study indicates that submarine mass wasting is widespread in the western Galapagos, suggesting that the production of small-scale downslope movement is part of the erosive nature of these oceanic volcanic islands.

The Eel River watershed has a high concentration of slow-moving landslides, or earthflows, due to argillaceous mélange bedrock and high tectonic uplift. Earthflows within this area are highly dissected by ephemeral channels, or gullies. Despite the pervasiveness of gullying in this area, the role of fluvial systems in relation to earthflows and varying uplift is poorly understood. To understand the role of earthflows and tectonics in dictating channel processes, we investigate channels in areas of differential uplift and mass failure activity. Channel networks are connected and continuous in catchments without earthflows, and disconnected and prone to bank failure on earthflow surfaces. Gully profiles are influenced BY earthflow undulations, which attenuate with fluvial incision after earthflows cease activity. We find notable differences in fluvial dissection between areas of high and low landslide activity. We find that mass wasting and local bedrock have a strong influence on formation and organization of channels.

Land-use planning takes into consideration geologic hazards in order to protect both life and property. One type of geologic hazard is mass movement. Mass movement is a collective term for the downslope movement of mass units of debris e.g., bedrock, soil, and subsurface material, resulting from the influence of gravity and involving transporting media such as ice, snow, water, and air. As population increases, further pressures are placed on existing land use. Many areas once considered unsuitable for development due to steep slope or other physical characteristics are now experiencing problems. These areas, due to their physical characteristics, can be susceptible to mass movement. The problem is, information related to the areal distribution of susceptibility is most often not available for input to the land-use planning process. This thesis is proposing a methodology to provide general-level mass movement susceptibility maps. The methodology is a computer application utilizing the Harvard I. M. G. R. l. D. (IMGRID) System. IMGRID is a system using grid cells as the basic units of data storage, analysis, retrieval, and display. Basically, the methodology consists of three major components or phases: (1) providing the computer with data acceptable to the machine and computer programs (input); (2) manipulation of the data and storage of map results within the machine's memory (processing); and (3) the retrieval and display of results (output). The processing of the data is organized around susceptibility models which generate computer maps identifying areas susceptible to mass movements. Areas susceptible to moss movements are defined as portions of the landscape characterized by a set of natural characteristics existing in a stable state which will yield a failure of the material if acted upon by an external or internal triggering event either natural or man-induced. The methodology was applied to a small area in Southwest Washington as a demonstration of how one mechanically follows it from beginning to end. Nine mass movement models were constructed based on the Varnes’ classification system and applied to a data bank containing eleven data variables. The susceptibility mops generated were analyzed to determine the significant mapping classes using the statistical output from IMGRID.

Landslides represent a serious hazard to people and property in the Pacific Northwest. Currently, the factors leading to sudden catastrophic failure vs. gradual slow creeping are not well understood. Utilizing high-resolution monitoring techniques at a sub-annual temporal scale can help researchers better understand the mechanics of mass wasting processes and possibly lead to better mitigation of their danger. This research used historical imagery analysis, precipitation data, aerial lidar analysis, Structure from Motion (SfM) photogrammetry, terrestrial laser scanning (TLS), and hydrologic measurements to monitor displacement of the Silt Creek Landslide in the western Cascade Mountain Range in Linn County, Oregon. This landslide complex is ~4 km long by ~400 m wide. The lower portion of the landslide reactivated following failure of an internal scarp in June 2014. Precipitation was measured on site and historical precipitation data was determined from a nearby SNOTEL site. Analysis of aerial lidar data found that the internal scarp failure deposited around 1.00x106 m3 of material over an area of 1.20x105 m2 at the uppermost portion of the reactivated slide. Aerial lidar analysis also found that displacement rates on the slide surface were as high as 3 m/yr during the 2015 water year, which was the year immediately following the failure. At the beginning of the 2016 water year, very low altitude aerial images were collected and used to produce point cloud data, via SfM, of a deformed gravel road which spans a portion of the reactivated slide. The SfM data were complimentary to the aerial and TLS scans. The SfM point cloud had an average point density of >7500 points per square meter. The resulting cloud was manipulated in 3D software to produce a model of the road prior to deformation. This was then compared to the original deformed model. Average displacement found in the deformed gravel road was 7.5 m over the 17 months between the scarp failure and the collection of the images, or ~3 m/yr. TLS point clouds were collected quarterly over the course of the 2016 water year at six locations along the eastern margin of the reactivated portion of the landslide. These 3D point cloud models of the landslide surface had an average density of 175 points per square meter. Scans were georeferenced to UTM coordinates and relative alignment of the scans was accomplished by first using the iterative closest point algorithm to align stable, off-slide terrain, and then applying the same rigid body translation to the entire scan. This was repeated for each scan at each location. Landmarks, such as tree trunks, were then manually selected at each location and their coordinates were recorded from the initial scan and each successive scan to measure displacement vectors. Average annual displacement for the 2016 water year ranged from a maximum of 0.92 m/yr in the uppermost studied area of the slide, to a low of 0.1 m/yr at the toe. Average standard deviation of the vectors of features on stable areas was 0.039 m, corresponding to a minimum detectable displacement of about ±4 cm. Displacement totals decreased with increasing distance downslope from the internal scarp failure. Additionally, displacement tended to increase with increasing distance laterally onto the slide body away from the right margin at all locations except the uppermost, where displacement rates were relatively uniform for all landmarks. Volumetric discharge measurements were collected for Silt Creek in 2016 using salt dilution gauging and found that discharge in the upslope portion of the study area was ~1 m3/s and increased to ~1.6 m3/s in the downslope portion. Landslide displacement rates were found to be much lower during the 2016 water year than during the 2015 water year, despite higher precipitation. This suggests that the over-all displacement trend was decoupled from precipitation values. Displacement rates at all locations on the slide decreased with each successive scan period with some portions of the landslide stopping by autumn of 2016, suggesting the study captured the slide as it returned to a state of stability. The spatial and temporal pattern of displacement is consistent with the interpretation that the landslide reactivation was a response to the undrained load applied by the internal scarp failure. This finding highlights the importance of detailed landslide monitoring to improve hazard estimation and quantification of landslide mechanics. This study provides new evidence that supports previous research showing that internal processes within landslide complexes can have feedback relationships, combines several existing 3D measurement tools to develop a detailed landslide monitoring methodology, uses a novel approach to landslide surface deformation measurements using SfM, and suggests that landslide initiation models which rely heavily on precipitation values may not account for other sources of landslide activation.

Thesis (M.S.)--Stanford University, 2000. / Submitted to the Department of Geological and Environmental Sciences. Copyright by the author.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-04-19T16:19:47Z No. of bitstreams: 1 DISSERTJULIANAGRODRIGUES.pdf: 4883356 bytes, checksum: 5706faa288cd5541e1bfe8cc446e591b (MD5) / Made available in DSpace on 2016-04-19T16:19:47Z (GMT). No. of bitstreams: 1 DISSERTJULIANAGRODRIGUES.pdf: 4883356 bytes, checksum: 5706faa288cd5541e1bfe8cc446e591b (MD5) / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / Em janeiro de 2011, a região serrana do Estado do Rio de Janeiro foi atingida por inúmeros movimentos de massa em um evento denominado de “Megadesastre”. A ocorrência de movimentos de massa depende da disponibilidade de material a ser mobilizado, e essa disponibilidade está relacionada com o intemperismo. Dessa forma, essa dissertação buscou avaliar as transformações geoquímicas e mineralógicas em dois perfis de intemperismo desenvolvidos sobre rocha granítica, na bacia do Córrego do Príncipe (Teresópolis/RJ), e a relação com a ocorrência de movimentos de massa. Nas análises químicas empregaram-se os métodos de ativação neutrônica (AAN) e fluorescência de raios-X (FRX). Já na mineralogia utilizou-se petrografia, observação em lupa e difração de raios-X (DRX), e na granulometria, peneiramento e difratometria a laser. A análise estatística multivariada indicou a separação de quatro grupos: G1 - apresenta o maior grau de dissimilaridade e é formado por material ferro-manganoso; G2 - amostras com menor grau de alteração, onde foi verificada a presença de plagioclásio e a escassez de minerais secundários, além da presença de material rochoso (corestones) menos alterado e material inconsolidado com textura grossa; G3 e G4 - apesar de apresentarem fortes similaridades, estão em estágios de alteração diferentes, sendo a principal diferença a mineralogia das frações finas (silte/argila): em G3, há plagioclásio, caulinita e gibbsita, enquanto que em G4 verificou-se a ausência de feldspatos e presença desses minerais secundários, indicando que as amostras em G3 estão em menor estágio de alteração do que as de G4. Quanto ao comportamento dos elementos químicos, houve um empobrecimento em K2O, Na2O, CaO, Rb, Ba e ETR, relacionado principalmente com a alteração dos felspatos, e enriquecimento em SiO2 e Al2O3 (relacionado aos minerais detríticos e neoformados), Fe2O3, TiO2 e MgO, referente a alteração da biotita. O estudo permitiu elaborar um modelo de transformação geoquímica, mineralógica e textural, a partir do qual se pode concluir que a formação de corestones juntamente com a mobilização e reconcentração de elementos e argilominerais, atuaram como heterogeneidades dentro desses perfis de alteração. Estes processos tornaram os perfis susceptíveis a movimentos de massa, mostrando assim uma inter-relação entre o estudo da evolução geoquímica e mineralógica, e a estabilidade mecânica do material / On January 2011, the mountainous region of Rio de Janeiro state was affected by a great number of landslides. This event was called "Megadisaster". The occurrence of landslide depends on the presence of material to be mobilized due to weathering processes. This work aims to assess the geochemical and mineralogical changes in two granite weathering profiles in Córrego do Príncipe watershed (Teresópolis / RJ) related to landslides. Instrumental Neutron Activation Analysis (INAA) and X-ray fluorescence (XRF) were used to quantify the chemical compositions of weathering profile samples. Mineralogy was done by X-ray diffraction analysis (XRD) and by petrography. Particle size analysis was done by sieving and laser diffraction. A multivariate statistical analysis of the data showed four groups: G1 is quite different from the other groups and is characterized by an iron-manganous material; G2 represents the material with the lower degree of weathering. The presence of plagioclase, the lack of secondary minerals, the corestones and the coarse grain size of the unconsolidated samples explain this group; G3 and G4 are fairly homogeneous. They are the most weathered samples of both profiles consisting of secondary minerals and little or no plagioclase present. The main difference between these groups is silt and clay mineralogy. The elements mobility during weathering process showed a depletion of K2O, Na2O, CaO, Rb, Ba and REE (mainly due to feldspar weathering), while SiO2, Al2O3 (due to detrital and secondary mineral growth) Fe2O3, TiO2 and MgO (due to biotite weathering) increase. This study allowed the elaboration of a geochemical, mineralogical and particle size weathering model. The production of corestones, the mobilization and concentration of elements and clay minerals acted as heterogeneities within these profiles, leaving them susceptible to landslides