Regional and local changes in the climate have been driving rapid glacial retreat in many glaciers since the Little Ice Age. This retreat provides a unique opportunity to study succession across the chronosequences of glacier forelands. Patterns of plant colonization and succession on terrain exposed by retreating glaciers give insight into factors influencing alpine ecosystem change and recovery. Understanding these patterns and processes is important for conserving alpine landscapes and flora as glaciers disappear. This study sought to investigate how various biotic and abiotic factors influence plant successional patterns in the dynamic alpine environment of Sperry Glacier, a Little Ice Age, mid-latitude cirque glacier in Glacier National Park, Montana. Through field data collection, additional Geographic Information System (GIS) derived variables, and subsequent geostatistical analysis, I specifically assessed: (1.) vegetative trends (percent cover, species richness, Shannon's diversity, species evenness, composition, and species turnover) over a 170-year chronosequence, and (2.) vegetative trends over field and GIS-derived site conditions (e.g., surface fragmentation, concavity, flow accumulation, and solar irradiance). Sixty-one plots (each 8 square meters) were placed throughout the glacier foreland using a random sample stratified by terrain date. Percent cover, species richness, Shannon's diversity, and species evenness were calculated for each plot. All sampled vegetation was identified with taxonomic resolution down to species whenever possible. I assessed vegetative trends across terrain age ranges using Kruskal-Wallis and Dunn's tests. I used two models, generalized linear models (GLMs) and Classification and Regression Trees (CARTs), to assess field and GIS-derived biophysical correlates (e.g., surface fragmentation, concavity, terrain variables, and solar irradiance with vegetative trends), followed by Kruskal-Wallis tests, Dunn's tests, and scatterplots. Species richness and vegetation cover were greater on older terrain. Plant composition changed over terrain age, with Penstemon ellipticus favoring older terrain and Boechera lemmonii favoring moderately aged terrain. Moderate drainage and concave plots, which were important in the GLMs, explained increased species richness and Shannon's diversity across different site conditions. The CARTs were able to predict species richness, vegetation cover, Shannon's diversity, and species evenness with surface fragment sized from gravel to cobble, topographic position index, and flow accumulation. These findings show that both temporal and biophysical site conditions influence successional trends across the foreland, though different vegetation measures are most influenced differently. / Master of Science / Regional and local changes in the climate have been driving rapid glacial retreat in many glaciers since the Little Ice Age. This retreat provides a unique opportunity to study succession across glacier foreland terrain that has been uncovered for different lengths of time. Patterns of plant colonization and succession on terrain exposed by retreating glaciers give insight into factors influencing alpine ecosystem change and recovery. Understanding these patterns and processes is important for conserving alpine landscapes and flora as glaciers disappear. This study sought to investigate how various biotic and abiotic factors influence plant successional patterns in the dynamic alpine environment of Sperry Glacier, a Little Ice Age, mid-latitude glacier in Glacier National Park, Montana. Through field data collection, additional Geographic Information System (GIS) derived variables, and subsequent geostatistical analysis, I specifically assessed: (1.) vegetative trends (percent cover, species richness, Shannon's diversity, species evenness, composition, and species turnover) over terrain uncovered between zero and 170-year, and (2.) vegetative trends over field and GIS-derived site conditions (e.g., surface fragmentation, concavity, flow accumulation, and solar irradiance). Sixty-one plots (each 8 square meters) were randomly placed within each terrain age range throughout the glacier foreland. Percent cover, species richness, Shannon's diversity, and species evenness were calculated for each plot. Shannon's diversity is a measurement of a community's diversity and uses both species richness and evenness to calculate diversity. All sampled vegetation was identified with taxonomic resolution down to species whenever possible. I assessed vegetative trends across terrain age using several statistical comparison tests. I used two types of statistical models to assess field and GIS-derived biophysical correlates (e.g., surface fragmentation, concavity, terrain variables, and solar irradiance with vegetative trends), followed by comparison tests and scatterplots. Species richness and vegetation cover were greater on older terrain. Plant composition changed over terrain age, with the species Penstemon ellipticus (rocky ledge penstemon) favoring older terrain and Boechera lemmonii (Lemmon's rockcress) favoring moderately aged terrain. Moderate drainage and concave plots explained increased species richness and Shannon's diversity across different site conditions. Species richness, vegetation cover, Shannon's diversity, and species evenness could be predicted with surface fragments sized from gravel to cobble, topographic position index, and flow accumulation. These findings show that both temporal and biophysical site conditions influence successional trends across the foreland, though different vegetation measures are most influenced differently.

Les glaciers des Alpes françaises subissent un recul généralisé depuis la fin du Petit Âge Glaciaire (PAG). Dans le contexte actuel d'élévation de la température et du fait des nombreux enjeux auxquels ils sont associés, l'amélioration de leur suivi apparaît indispensable. Avant ce travail, il n'existait pas d'étude exhaustive récente concernant l'ensemble des glaciers des Alpes françaises, les travaux de Mougin et de Vivian datant respectivement du milieu des années 1920 et 1970. L'objectif de ce travail est de dresser un inventaire diachronique des glaciers des Alpes françaises et de leurs marges proglaciaires. Les données de cet inventaire servent ensuite de base à l'étude des modalités du retrait glaciaire depuis la fin du PAG et à l'établissement de méthodes pour détecter les secteurs susceptibles d'être affectés par des instabilités. L'inventaire diachronique des glaciers des Alpes françaises est réalisé à 3 dates : (i) 2006-2009 à partir des orthophotographies récentes de l'IGN, (ii) 1967-1971 à partir des premières éditions des cartes topographiques 1 :25 000 de l'IGN, et (iii) la fin du PAG (pour les massifs du Mont Blanc, de la Vanoise et des Ecrins), en croisant documents anciens et données géomorphologiques acquises sur le terrain et par photo-interprétation. Les données sont organisées dans un Système d'Information Géographique (SIG) qui permet d'associer cartographie et base de données. La superficie des glaciers était de 275 km² en 2006-2009, 369 km² en 1967-1971 et 544 km² à la fin du PAG pour les massifs du Mont Blanc, de la Vanoise et des Ecrins. A l'échelle régionale, les glaciers ont perdu 25 % de leur superficie depuis la fin des années 1960 et 50 % de leur superficie depuis la fin du PAG. La rétraction des glaciers est environ 2,5 fois plus rapide entre 1967-1971 et 2006-2009 qu'entre la fin du PAG et 1967-1971. A l'échelle individuelle, les glaciers ont perdu en moyenne 52 % de leur superficie entre 1967-1971 et 2006-2009, et 115 ont même disparu. A l'échelle régionale comme individuelle, le retrait glaciaire présente des tendances différentes selon les massifs, la taille des glaciers et leur exposition Des méthodes simples, basées sur les données des inventaires des glaciers et des marges proglaciaires sont établies afin d'identifier les lacs potentiellement instables, les secteurs englacés favorables à la formation de futurs lacs, au déclenchement d'avalanches de séracs ou susceptibles d'être déstabilisés en masse, et les marges proglaciaires favorables à l'occurrence de glissements ou de laves de débris. / French alpine glaciers are retreating since the end of the Little Ice Age (LIA). In the context of the increasing air temperature and because of issues that they represent, it is necessary to improve glacier monitoring. Before the present study, the only two inventories covering the entire French Alps were made by Mougin (1925) and Vivian (1975). The main goal of this study is to realise a multi-temporal glacier inventory of glaciers in the French Alps and of their proglacial margins. Data from this inventory are used to study glacial retreat since the end of the LIA and to develop methods to detect sector that could be affected by instabilities. Multi-temporal inventory of French Alpine glacier glaciers is made for 3 dates: (i) 2006-2009, based on IGN recent orthophotographs, (ii) 1967-1971, based on 1: 25 000 IGN topographic maps, and (iii) the end of the LIA (for Mont Blanc, Vanoise and Ecrins massifs), crossing old documents and geomorphologic data based on field work and interpretation of orthophotographs. Data are integrated in a Geographical Information System (GIS), combining mapping and data base. Glaciers in the French Alps covered 275 km² in 2006-2009, 369 km² in 1967-1971 and 544 km² at the end of the LIA for Mont Blanc, Vanoise and Ecrins massifs. At a regional scale, glaciers lost 25 % of their 1967-1971 area and 50 % of their LIA area. Glacier shrinkage between 1967-1971 and 2006-2009 is about 2.5 times higher than between the end of the LIA and 2006-2009. At an individual scale glaciers lost 52 % of their area between 1967-1971 and 2006-2009, and 115 disappeared. At regional or individual scale, different trends in glacier shrinkage are observed according to the massifs, size and aspect of the glaciers. Simple methods, based on glaciers inventory and proglacial margins data, are developed in order to identify potential unstable lakes, glaciated sectors prone to glacier lake formation, ice avalanche triggering or mass destabilization, and proglacial margins where sliding or debris flows could occur.

Este trabalho objetiva investigar a dinâmica geomorfológica glacial das áreas livres de gelo na Península Potter, Ilha Rei George, Antártica, em resposta à recente retração da geleira Polar Club. O mapeamento geomorfológico e a interpretação da evolução dos sistemas lacustres entre 2006 e 2011 das áreas livres de gelo na Península Potter foi realizado através da interpretação visual em uma imagem Quickbird (RGB432), em imagens COSMO-SkyMed polarizações VV e HH em modo spotlight processadas com filtros espaciais e perfis topográficos. Também foram considerados os aspectos morfométricos da península, interpretados através da geração de mapas de hipsometria, declividade, curvas de nível e sombreamento. A variação frontal da geleira Polar Club entre os anos de 1981 a 2015 foi obtida pela análise temporal de imagens Landsat. O mapeamento geomorfológico da Península Potter evidenciou os processos geomorfológicos proglaciais e o padrão de disposição espacial das feições lineares marginais ao gelo, como cordões morâinicos e feições glaciofluviais (relacionadas ao aporte da fusão sazonal da neve e do gelo), bem como terraços marinhos, ravinas e afloramentos rochosos. As imagens COSMO-SkyMed e a aplicação de filtros Passa Alta e Direcionais possibilitaram a delimitação das feições de interesse com maior nitidez. O modelo de evolução da variação frontal da geleira Polar Club indica que condição de último avanço glacial registrado pela geomorfologia proglacial pode estar relacionado à Pequena Idade do Gelo e que houve um contínuo processo de retração desde então. Entre 1981-2015 evidenciou-se a redução de área de 2,95km2 para a geleira Polar Club (perda de área total de 9,4%). Este processo pode estar relacionado com a tendência de aumento das temperaturas médias do ar, a tendência de aumento de dias com precipitação líquida no verão e o número de dias em que a temperatura média ultrapassou os 0°C na região nas últimas décadas. O recuo da geleira Polar Club é pouco expressivo quando comparado a outras geleiras da Ilha Rei George, no entanto, quando se observa as áreas expostas evidenciou-se que houve um aumento significativo (36,9%) no período. Através da análise da evolução dos depósitos morâinicos da Península Potter foi possível identificar três fases principais de formação de morâinas que evidenciam antigas posições da frente da geleira durante períodos de estabilização frontal. A análise da evolução dos sistemas lacustres na área de estudo evidenciou que diversos lagos sofreram alterações de área em resposta à dinâmica de retração glacial registrada para os últimos 34 anos. / This study aimed to investigate the glacial geomorphological dynamics of the ice-free areas in the Peninsula Potter, King George Island, Antarctica, in response to the recent Polar Club Glacier retreat processes. The geomorphological mapping and lacustrine systems evolution modelling between 2006-2011 were obtained with Quickbird (RGB432) image, application of the spatial digital filters in COSMO-SkyMed (cross and co-polarization, spotlight mode) images and topographic profiles visual interpretations. Also considered were the morphometric aspects of the peninsula, interpreted by generating hypsometry, slope, contour and shaded relief maps. The Polar Club Glacier frontal variation between 1981-2015 was obtained with Landsat temporal analysis. The Potter Peninsula geomorphological mapping evidenced the proglacial and geomorphological processes and the spatial distribution pattern of linear marginal to ice features, as morainic ridges and glaciofluvial features, related to the contribution of the seasonal melting of snow and ice, marine terraces, ravines and rocky outcrops. The High Pass and directional filters in COSMO-SkyMed images provided conditions for geomorphological features. The frontal glacier fluctuations modelling indicated that last glacial advance condition recorded by proglacial geomorphologic can be related Little Ice Age and continuous retreat process. Between 1981-2015 the Polar Club glacier lost 2,95km2 of total area (9,4% of total area). The retreat process can be related to the trend of rising average temperatures in recent decades, trend of increase in days with liquid precipitation in summer and the number melting degree days. The Polar Club Glacier retreat is not very significant when compared to other glaciers of King George Island, however, when observing the exposed areas was evident that there was a significant increase (36.9%). The moraine deposits evolution analysis in Peninsula Potter provided conditions for identify three main phases of moraines deposition and that show past glacier front positions during periods of glacier marginal stabilization. The analysis of the evolution of lacustrine systems in the study area evidenced changes in various lakes during last 34 years in response of glacial retreat dynamics.

Este trabalho objetiva investigar a dinâmica geomorfológica glacial das áreas livres de gelo na Península Potter, Ilha Rei George, Antártica, em resposta à recente retração da geleira Polar Club. O mapeamento geomorfológico e a interpretação da evolução dos sistemas lacustres entre 2006 e 2011 das áreas livres de gelo na Península Potter foi realizado através da interpretação visual em uma imagem Quickbird (RGB432), em imagens COSMO-SkyMed polarizações VV e HH em modo spotlight processadas com filtros espaciais e perfis topográficos. Também foram considerados os aspectos morfométricos da península, interpretados através da geração de mapas de hipsometria, declividade, curvas de nível e sombreamento. A variação frontal da geleira Polar Club entre os anos de 1981 a 2015 foi obtida pela análise temporal de imagens Landsat. O mapeamento geomorfológico da Península Potter evidenciou os processos geomorfológicos proglaciais e o padrão de disposição espacial das feições lineares marginais ao gelo, como cordões morâinicos e feições glaciofluviais (relacionadas ao aporte da fusão sazonal da neve e do gelo), bem como terraços marinhos, ravinas e afloramentos rochosos. As imagens COSMO-SkyMed e a aplicação de filtros Passa Alta e Direcionais possibilitaram a delimitação das feições de interesse com maior nitidez. O modelo de evolução da variação frontal da geleira Polar Club indica que condição de último avanço glacial registrado pela geomorfologia proglacial pode estar relacionado à Pequena Idade do Gelo e que houve um contínuo processo de retração desde então. Entre 1981-2015 evidenciou-se a redução de área de 2,95km2 para a geleira Polar Club (perda de área total de 9,4%). Este processo pode estar relacionado com a tendência de aumento das temperaturas médias do ar, a tendência de aumento de dias com precipitação líquida no verão e o número de dias em que a temperatura média ultrapassou os 0°C na região nas últimas décadas. O recuo da geleira Polar Club é pouco expressivo quando comparado a outras geleiras da Ilha Rei George, no entanto, quando se observa as áreas expostas evidenciou-se que houve um aumento significativo (36,9%) no período. Através da análise da evolução dos depósitos morâinicos da Península Potter foi possível identificar três fases principais de formação de morâinas que evidenciam antigas posições da frente da geleira durante períodos de estabilização frontal. A análise da evolução dos sistemas lacustres na área de estudo evidenciou que diversos lagos sofreram alterações de área em resposta à dinâmica de retração glacial registrada para os últimos 34 anos. / This study aimed to investigate the glacial geomorphological dynamics of the ice-free areas in the Peninsula Potter, King George Island, Antarctica, in response to the recent Polar Club Glacier retreat processes. The geomorphological mapping and lacustrine systems evolution modelling between 2006-2011 were obtained with Quickbird (RGB432) image, application of the spatial digital filters in COSMO-SkyMed (cross and co-polarization, spotlight mode) images and topographic profiles visual interpretations. Also considered were the morphometric aspects of the peninsula, interpreted by generating hypsometry, slope, contour and shaded relief maps. The Polar Club Glacier frontal variation between 1981-2015 was obtained with Landsat temporal analysis. The Potter Peninsula geomorphological mapping evidenced the proglacial and geomorphological processes and the spatial distribution pattern of linear marginal to ice features, as morainic ridges and glaciofluvial features, related to the contribution of the seasonal melting of snow and ice, marine terraces, ravines and rocky outcrops. The High Pass and directional filters in COSMO-SkyMed images provided conditions for geomorphological features. The frontal glacier fluctuations modelling indicated that last glacial advance condition recorded by proglacial geomorphologic can be related Little Ice Age and continuous retreat process. Between 1981-2015 the Polar Club glacier lost 2,95km2 of total area (9,4% of total area). The retreat process can be related to the trend of rising average temperatures in recent decades, trend of increase in days with liquid precipitation in summer and the number melting degree days. The Polar Club Glacier retreat is not very significant when compared to other glaciers of King George Island, however, when observing the exposed areas was evident that there was a significant increase (36.9%). The moraine deposits evolution analysis in Peninsula Potter provided conditions for identify three main phases of moraines deposition and that show past glacier front positions during periods of glacier marginal stabilization. The analysis of the evolution of lacustrine systems in the study area evidenced changes in various lakes during last 34 years in response of glacial retreat dynamics.

Este trabalho objetiva investigar a dinâmica geomorfológica glacial das áreas livres de gelo na Península Potter, Ilha Rei George, Antártica, em resposta à recente retração da geleira Polar Club. O mapeamento geomorfológico e a interpretação da evolução dos sistemas lacustres entre 2006 e 2011 das áreas livres de gelo na Península Potter foi realizado através da interpretação visual em uma imagem Quickbird (RGB432), em imagens COSMO-SkyMed polarizações VV e HH em modo spotlight processadas com filtros espaciais e perfis topográficos. Também foram considerados os aspectos morfométricos da península, interpretados através da geração de mapas de hipsometria, declividade, curvas de nível e sombreamento. A variação frontal da geleira Polar Club entre os anos de 1981 a 2015 foi obtida pela análise temporal de imagens Landsat. O mapeamento geomorfológico da Península Potter evidenciou os processos geomorfológicos proglaciais e o padrão de disposição espacial das feições lineares marginais ao gelo, como cordões morâinicos e feições glaciofluviais (relacionadas ao aporte da fusão sazonal da neve e do gelo), bem como terraços marinhos, ravinas e afloramentos rochosos. As imagens COSMO-SkyMed e a aplicação de filtros Passa Alta e Direcionais possibilitaram a delimitação das feições de interesse com maior nitidez. O modelo de evolução da variação frontal da geleira Polar Club indica que condição de último avanço glacial registrado pela geomorfologia proglacial pode estar relacionado à Pequena Idade do Gelo e que houve um contínuo processo de retração desde então. Entre 1981-2015 evidenciou-se a redução de área de 2,95km2 para a geleira Polar Club (perda de área total de 9,4%). Este processo pode estar relacionado com a tendência de aumento das temperaturas médias do ar, a tendência de aumento de dias com precipitação líquida no verão e o número de dias em que a temperatura média ultrapassou os 0°C na região nas últimas décadas. O recuo da geleira Polar Club é pouco expressivo quando comparado a outras geleiras da Ilha Rei George, no entanto, quando se observa as áreas expostas evidenciou-se que houve um aumento significativo (36,9%) no período. Através da análise da evolução dos depósitos morâinicos da Península Potter foi possível identificar três fases principais de formação de morâinas que evidenciam antigas posições da frente da geleira durante períodos de estabilização frontal. A análise da evolução dos sistemas lacustres na área de estudo evidenciou que diversos lagos sofreram alterações de área em resposta à dinâmica de retração glacial registrada para os últimos 34 anos. / This study aimed to investigate the glacial geomorphological dynamics of the ice-free areas in the Peninsula Potter, King George Island, Antarctica, in response to the recent Polar Club Glacier retreat processes. The geomorphological mapping and lacustrine systems evolution modelling between 2006-2011 were obtained with Quickbird (RGB432) image, application of the spatial digital filters in COSMO-SkyMed (cross and co-polarization, spotlight mode) images and topographic profiles visual interpretations. Also considered were the morphometric aspects of the peninsula, interpreted by generating hypsometry, slope, contour and shaded relief maps. The Polar Club Glacier frontal variation between 1981-2015 was obtained with Landsat temporal analysis. The Potter Peninsula geomorphological mapping evidenced the proglacial and geomorphological processes and the spatial distribution pattern of linear marginal to ice features, as morainic ridges and glaciofluvial features, related to the contribution of the seasonal melting of snow and ice, marine terraces, ravines and rocky outcrops. The High Pass and directional filters in COSMO-SkyMed images provided conditions for geomorphological features. The frontal glacier fluctuations modelling indicated that last glacial advance condition recorded by proglacial geomorphologic can be related Little Ice Age and continuous retreat process. Between 1981-2015 the Polar Club glacier lost 2,95km2 of total area (9,4% of total area). The retreat process can be related to the trend of rising average temperatures in recent decades, trend of increase in days with liquid precipitation in summer and the number melting degree days. The Polar Club Glacier retreat is not very significant when compared to other glaciers of King George Island, however, when observing the exposed areas was evident that there was a significant increase (36.9%). The moraine deposits evolution analysis in Peninsula Potter provided conditions for identify three main phases of moraines deposition and that show past glacier front positions during periods of glacier marginal stabilization. The analysis of the evolution of lacustrine systems in the study area evidenced changes in various lakes during last 34 years in response of glacial retreat dynamics.

Modern Pine Island and Thwaites Glaciers, which both drain into Pine Island Bay, are some of the fastest moving portions of the cryosphere and may be the most unstable ice streams in Antarctica. I examined over 133 cores to conduct a detailed sedimentological facies analysis. These data, augmented by new radiocarbon and 210Pb dates, and bathymetric data, are used to reconstruct the post-LGM deglacial history of PIB and gain a better understanding of the causes of ice sheet retreat. My results record a clear retreat stratigraphy in PIB composed of, from top to base; terrigenous sandy silt (plumite), pebbly sandy mud (ice-proximal glacimarine), and till. Initial retreat from the outer-continental shelf began shortly after the LGM and before 16.4 k cal yr BP, in response to rising sea level. Bedforms in outer PIB document episodic retreat in the form of back-stepping grounding zone wedges and are associated with proximal glacimarine sediments. A sub-ice shelf facies is observed in central PIB that spans ∼12.3–10.6 k cal yr BP. Widespread impingement of warm water onto the continental shelf caused an abrupt change from sub-ice shelf sedimentation to distal glacimarine sedimentation dominated by dispersal of terrigenous silt between 7.8 and 7.0 k cal yr BP. The uppermost sediments in Pine Island Bay were hydrodynamically sorted by meltwater plumes. Inner Pine Island Bay contains several large basins that are linked by channels. The most recent release of sediment coincides with rapid retreat of the grounding line, and has an order of magnitude greater flux relative to the entire unit, indicating episodic sedimentation. This is the first identification of a meltwater-derived deposit in Antarctica and demonstrates that punctuated meltwater-intensive glacial retreat occurred at least three times throughout the Holocene in this region. Quartz sand grains were used to conduct an analysis of mode of transport for sediments in the Antarctic Peninsula region from the Eocene to present to record the onset of glaciation. Glacial transport imparts a unique suite of microtextures on quartz grains from high shear-stresses. Eocene samples are free of glacial influence. Late Eocene samples show the inception of glacially derived high-stress microtextures, marking the onset of alpine glaciation. Oligocene grains are similar to the late Eocene samples. Middle Miocene microtextures are characteristic of transport from far-field large ice sheets, originating from ice rafting from the West Antarctic Ice Sheet. The Pliocene and Pleistocene samples indicate the existence of the northern Antarctic Peninsula Ice Sheet at this time, consistent with other proxies.

The plate-boundary Alpine Fault runs immediately offshore of the popular tourist destination of Milford Sound, which is visited by more than half a million tourists each year. Glaciers retreated from the fiord between ~24-16 ka, leaving behind a legacy of extreme topography, including some of the world's highest sea cliffs, which tower nearly 2 km above the fiord. Visitors come to view the spectacularly steep and rugged landscape, with many cruising the fiord by boat. This project utilizes surface exposure dating (TCND) of glacially modified surfaces, to gain further insight into the glacier retreat history of Milford Sound. Exposure dates from strategic locations near the entrance to the fiord indicate that the main trunk glacier had retreated about 9 km from its peak LGM position by ~18 ka. Additional TCND and calibrated Schmidt Hammer data from a range of positions within the Milford catchment provide strong evidence that the main trunk glacier receded rapidly after about 18 ka, retreating a further 16 km to a position near the present-day confluence of the Tutoko and Cleddau rivers, by ~16 ka. Available seismic reflection data suggest that post-glacial sediment infill has been strongly influenced by massive deposits of rock avalanche debris. New high-resolution bathymetric and seismic reflection data reveals the presence of at least 18 very large post-glacial rock avalanche deposits which blanket ~40% of the fiord bottom. Geomorphic mapping and field investigation reveal the presence of at least ten additional very large to giant terrestrial landslide deposits in the lower Milford catchment; radiocarbon and surface exposure dating indicate that these events occurred during the Holocene, between ~9-1 ka. Ages of six of these deposits are in agreement with published rupture dates on the southern on-shore portion of the Alpine Fault.

<p>Alpine glaciers around the world are in retreat and are unlikely to reverse course. This dissertation focuses on improving our understanding of the impact of glacial melt on mountainous alpine groundwater systems. Studies on glacial melt-groundwater interactions have become more prevalent, particularly in the past 5 years, because we are recognizing that the contribution of glacial melt to the hydrologic cycle is not limited to melt-season surficial streamflow. The importance of glacial melt to mountain groundwater systems has the potential to not only influence spring and streamflow generation, but also the longevity of alpine specific, and frequently endangered species, dependent on this source of recharge. This recharge may be vital for human water needs such as potable water, agriculture, and hydrothermal power.</p>The impact that a transition from glacial melt to snow- or rain-dominated streamflow and recharge will have on alpine ecosystems in a continually warming climate is far reaching. This dissertation: 1) tests whether glacial melt is an important source of recharge for mountain springs and their microbial communities, 2) investigates the spatial impact of glacial-melt recharge on residence times and flowpaths that support alpine springs, and 3) explores the impact of post-peak water on alpine baseflow using a statistical, timeseries approach. My results show that the groundwater systems in glaciated mountainous, alpine regions are particularly vulnerable to climate change. Springs in Mount Hood National Forest and Glacier National Park were sampled over a 4-year period, and in addition, publicly available long-term streamflow datasets were are also utilized. The chapters composing this work build upon each other, and compare and contrast the factors most important in glacial melt recharging the mountain-block. Information that is vital to the management of alpine water resources by landowners, watershed groups, scientists, and others interested in mountain groundwater systems in glaciated alpine regions is presented in the following pages.