Thesis (Ph. D.)--University of Oregon, 1999. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 225-237). Also available for download via the World Wide Web; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p9948021.

La faille Nord-Anatolienne est une faille décrochante dextre de 1500 km et la frontière de plaque entre l’Anatolie au sud et l’Eurasie au nord. Le mouvement vers l’Ouest de l’Anatolie par rapport à l’Eurasie à une vitesse de 21 mm/an est accommodé par le jeu de cette faille. Durant le 20ième siècle, cette faille a rompu d’est en ouest lors d’une séquence de larges tremblements de terre qui ont eu lieu à intervalles rapprochés. De nombreux géologues ont cherché à mieux comprendre l’histoire récente de cette faille, et plus parti-culièrement son histoire sismique ou paléosismologique. La recherche en paléosismologie consiste à contraindre en utilisant l’enregistrement sédimentaire existant la nature et la distribution des tremblements de terre passés. Dans cette thèse, j’ai effectué 4 investi-gations paléosismologiques le long de la faille Nord-Anatolienne dans des lieux où à chaque tremblement de terre la faille forme des escarpements à contre-pente et constitue un piège à sédiment. En étudiant la composition et la distribution des sols enfouis et ex-posés dans de larges tranchées creusées au travers de ces pièges sédimentaires, on peut identifier des « horizons sismiques » (c’est-à-dire la surface terrestre lors du séisme). En datant par le radiocarbone les matériaux déposés au-dessous (avant) et au-dessus (après) d’un horizon sismique, on peut contraindre à quel moment un paléoséisme a eu lieu. Fi-nalement dans cette thèse, j’ai compilé une base de donnée des chronologies de l’ensemble de paléoséismes documentés sur la faille Nord-Anatolienne. Grâce à cette base de données, j’ai pu déterminer l’occurrence des séismes avec une méthodologie cohérente, et analyser la chronologie obtenue à la fois qualitativement et quantitativement. L’analyse des données révèle que la faille Nord-Anatolienne ne rompt habituellement pas en cascade comme durant le 20ième siècle, et que l’activité de la faille est fortement influencé par les trois principaux régimes tectoniques existant en Turquie. Les variabilités d’activité le long de la faille pourraient résulter de contraintes normales à la faille, qui décroissent d’une façon générale de l’Est vers l’Ouest. Une décroissance des contraintes normales à la faille diminuerait localement le seuil de contrainte requis pour déclencher un séisme. Ceci explique l’observation que le temps de récurrence des séismes est plus court à l’Ouest. A l’Est, les ruptures sont plus variables, et le temps de récurrence est bimodal. Ceci peut être lié à des variations temporelles des contraintes normales à la faille, peut-être induites par le jeu sismique des failles Est-Anatolienne et de la Mer Morte.

Thesis (Ph.D.)--University of Rhode Island, 2007. / Includes bibliographical references (leaves 233-245).

Thesis (M.S.)--Humboldt State University, 2004. / Includes bibliographical references (leaves 59-65).

Oblique continental collision between the Pacific and Australian Plates in the central South Island of New Zealand (between c. 44 and 46°S) results in distributed reverse faulting. Only a few of these faults have been studied in detail, highlighting a major knowledge deficit in the earthquake behaviour, magnitude potential and contribution to seismic hazard for many faults in this part of the orogen. Three reverse faults are investigated in detail in this thesis: the Moonlight Fault Zone (MFZ), the Fox Peak Fault and the Forest Creek Fault. Geochronologic approaches, including Schmidt hammer exposure-age dating, radiocarbon dating, and optically stimulated luminescence dating, are combined with paleoseismic trenching, fault surface trace mapping, analysis of GPS and LiDAR survey data, and numerical modelling to characterise the rupture behaviour of these faults. A new Schmidt hammer chronofunction based on over 7000 clast analyses is developed that relates rebound value (R-value) to age for river terraces. The rapid, inexpensive, non-destructive, and statistically valid nature of this technique makes it widely applicable for age dating here and globally. I use Schmidt hammer exposure-age dating along with other geochronologic and surveying methods to show that stranded post-last glacial lake shorelines of Lake Wakatipu are undeformed and at a uniform elevation across the MFZ. This indicates an absence of uplift across the MFZ since c. 13 ka and suggests that this fault may be inactive or subject to long periods of interseismic quiescence despite its location in the active orogen. This result also challenges the long-held hypothesis that lake shorelines throughout central NZ are tilted due to isostatic rebound. Three segments of the Fox Peak Fault are identified through field mapping and surveying. Slip rates at over 50 locations along the 36.5 km total length of the fault (c. 1.5 mm yr⁻¹ maximum) co-vary with the bounding range topography and exhibit large gradients near intersecting NW-striking faults. Four paleoseismic trenches were excavated to determine if these segment boundaries represent barriers to earthquake rupture propagation. Evidence of 3-4 earthquakes since c. 16 ka on the two end segments with overlapping age uncertainties indicates that the recurrence interval of the fault is 2000-3000 years. The most recent event (MRE) occurred at c. 2.5 ka. Large single event displacement to length ratios on these segments and a single event scarp on the central segment indicate that while the segment boundaries control on-fault slip gradients, they are not likely to impede through-going ruptures in an earthquake. This is a relatively recent development from the long-term tectonic geomorphology, which is suggestive of range growth on separate faults.

Thesis (M.S.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 58-62). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.

Thesis (M.S.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 58-65). Also available via Humboldt Digital Scholar.

Seismic hazard models for Alaska require estimates of the size and frequency of prehistoric megathrust earthquakes. However, observations that place limits on the size of subduction paleoearthquakes along the Alaska-Aleutian subduction zone are scarce. To help place bounds on the along-strike extent of prehistoric Alaska-Aleutian subduction ruptures, we present stratigraphic and microfossil evidence of repeated tsunami inundation over the last ~400 years at Sitkalidak Island, located 0.5 km off the coast of south-central Kodiak Island. Peat cores collected from an estuary in southern Sitkalidak Island reveal three anomalous, laterally continuous sand beds with sharp upper and lower contacts preserved within a coastal peat sequence. The microfossil and lithostratigraphic characteristics of the sand beds, including the presence of anomalous marine planktonic diatoms, high fragmentation of diatoms, and upward fining sand sequences, indicate high-energy marine incursions consistent with tsunami inundation. Radiocarbon dating constrains the deposition of the sand beds to AD 1964, AD 1788, and ~400 cal yr B.P. The peat core stratigraphy and dates are consistent with tidal wetland stratigraphic records observed at sites ~90 km to the west at Sitkinak Island, and ~80 km to the east at Middle Bay, Kodiak Island. Diatom results from Sitkalidak Island suggest decimeter-scale subsidence during the deposition of the 1964 CE and 1788 CE sand bed. Deformation concurrent with the 1964 and 1788 ruptures along with the presence of a sand bed associated with the ~400 cal yr BP rupture at Sitkalidak help better define the western and eastern rupture limits, and thus the permissible maximum magnitudes, of past Alaska-Aleutian subduction zone ruptures. / Master of Science / The Alaska-Aleutian subduction zone experiences frequent great earthquakes over magnitude 8 which often produce far-reaching tsunamis. Seismic hazard models that help coastal communities predict and prepare for future hazards require estimates of the size and frequency of prehistoric earthquakes. Data for prehistoric earthquake events in the western region of the subduction zone is scarce. To help address the lack of prehistoric data and understand the rupture path and magnitude of past Alaska-Aleutian earthquakes, we present stratigraphic and microfossil evidence of repeated tsunami inundation over the last ~400 years at Sitkalidak Island, located 0.5 km off the coast of south-central Kodiak Island, Alaska. Sediment cores collected from a marsh in southern Sitkalidak Island record three laterally continuous sand beds with sharp stratigraphic contacts preserved within a coastal peat. Diatom microfossil and grain-size characteristics of the sand beds indicate high-energy marine incursions consistent with chaotic tsunami inundation. Radiocarbon dating places the age of sand bed deposition to AD 1964, AD 1788, and ~400 cal yr B.P. The sediment core stratigraphy and dating correlates well with sites investigated ~90 km to the west and ~80 km to the east. Diatom results from Sitkalidak Island point to small, decimeter scale coseismic subsidence during the deposition of the AD 1964 and AD 1788 sand beds. Land-level change concurrent with the 1964 and 1788 earthquakes along with the presence of a sand bed associated with the ~ 400 cal yr B.P. earthquake found at Sitkalidak Island help better define the earthquake rupture limits and maximum magnitudes of past Alaska-Aleutian subduction zone earthquakes.

Satellite image interpretation, geologic mapping, and paleoseismic trenching are used to investigate the Trans-Yamuna active fault system in the northwestern Doon Valley of the Indian Himalayan foothills. This east-west fault system is subparallel to and crosses the Main Boundary thrust near the structural transition from the Nahan salient to the Dehra Dun reentrant. The Trans-Yamuna active fault system may terminate to the east at a lateral ramp of the Main Boundary thrust. A south-side-up, relatively linear fault trace with variable fault dips suggests that the fault system is high-angle reverse with a component of strike-slip. It is subdivided into the Sirmurital, Dhamaun, and Bharli faults, which probably connect at depth. The Dhamaun fault is exposed where it cuts the late Holocene upper Bhatrog terrace deposit of the Giri River. A paleoseismic investigation of the Sirmurital fault at another Giri River terrace did not expose the fault, but it suggests that late Holocene terrace deposits there may be folded into a syncline parallel to fault strike. The fold axis of the syncline continues into bedrock to the west. Earthquakes in 1905, 1803, or perhaps earlier may have been the source of folding of the fine-grained sediments within this terrace deposit. The Trans-Yamuna active fault system is a secondary hangingwall fault that may accommodate some strain release above the decollement during large-magnitude earthquakes. Strike-slip motion may be related to the lateral translation of the Karakoram fault block and east-west extension of the southern Tibet block as a result of oblique convergence between the Indian and Eurasian plates in the northwest Himalaya. / Graduation date: 1999

Thesis (M.S.)--Humboldt State University, 2004. / Includes bibliographical references (leaves 59-65). Also available via the Internet.