Glaciers are the essential source of fresh water not only to human sustenance, but it is also vital for all lifeforms on earth. Glaciers are also key components in understanding rapid changes in climate. This makes understanding of glacier mass, extent, and overall state essential. In this dissertation, the objective was to analyze the state of snow and ice masses in the mid (California) and low latitude (Chile/Argentina) western American regions using geospatial technology. This study also analyzed the effects of anomalies in snow mass on the regional agricultural practices in California’s Central Valley. In the Southern Andes, the digital elevation models from Shuttle Radar Topographic Mission (SRTM) (the year 2000) were compared with the elevation footprints from the Geoscience Laser Altimeter System (GLAS) campaign for the years 2004 through 2008. Generally, in all sub-regions, the elevation values were lower than the elevation for the year 2000, which demarcates continuous recession of ice mass in the Andean region. Also, this study quantified snow cover extent and mass balance variation in the Sierra Nevada and Mt. Shasta regions in California. To unearth anomalies in snow mass, study used digital elevation models generated from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) between the year 2000 and 2015. A remarkable reduction in snow cover extent of about 80% was observed in the studied watersheds of California. Lastly, the impacts of snow mass anomalies on the total water storage (TWS) and agriculture land cover in the California’s Central Valley were quantified and geo-visualized. The study noticed the change in the land cover area of about 20% (6993 sq.km) due to the alteration of Agriculture land to impervious land covers. Most of the change in the agriculture land cover of about 4402 sq.km occurred in the San Joaquin and Tulare Basins of southern Central Valley region. This dissertation concludes that the increased temperature in the Andes and California has adversely impacted Cryosphere components in the region in the past decade. Besides, it provides valuable insights into the changing state of cryosphere components and highlights impacts of anomalies in TWS on a billion-dollar agricultural industry.

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Catalogs of seismic source parameters (hypocenter locations, origin times, and magnitudes) are vital for studying various Earth processes, greatly enhancing our understanding of the nature of seismic events, the structure of the Earth, and the dynamics of fault systems. Modern seismic analyses utilize supervised machine learning (ML) to build enhanced catalogs based on millions of examples of analyst-picked phase-arrivals in waveforms, yet the ability to characterize the time-varying spectral content of the waveforms underlying those catalogs remains lacking. Unsupervised machine learning (UML) methods provide powerful tools for inferring patterns from musical spectrograms with little a priori information, yet has been relatively underutilized in the field of seismology. In this thesis, I leverage advanced tools from UML to analyze the temporal spectral content of large sets of spectrograms generated by different mechanisms in two distinct geologic settings: icequakes and tremors at Gornergletscher (a Swiss temperate glacier) and repeating earthquakes from a 10-km-long creeping segment of the San Andreas Fault. The core algorithm in this work, now known as Spectral Unsupervised Feature Extraction, or SpecUFEx, extracts time-varying frequency patterns from spectrograms and reduces them into low-dimensionality fingerprints via a combination of non-negative matrix factorization and hidden Markov Modeling (Holtzman et al. 2018), optimized for large data sets via stochastic variational inference. This work describes the SpecUFEx algorithm and the suite of preprocessing, clustering, and visualization tools developed to create an UML workflow, SpecUFEx+, that is widely-accessible and applicable for many seismic settings. I apply theSpecUFEx+ workflow to single- and multi-station seismic data from Gornergletscher, and demonstrate how some fingerprint-clusters track diurnal tremor related to subglacial water flow, while others correspond to the onset of the subglacial and englacial components of a glacial lake outburst flood. I also discover periods of harmonic tremor localized near the ice-bed interface that may be related to glacial stick-slip sliding. I additionally apply the SpecUFEx+ workflow to earthquakes on the San Andreas Fault to unveil far more repeating earthquake sequences than previously inferred, leading to enhanced slip-rate estimates at seismogenic depths and providing a more detailed image of seismic gaps along the fault interface. Unsupervised feature extraction is a novel tool to the field of seismology. This work demonstrates how scientific insight can be gained through the characterization of the spectral-temporal patterns of large seismic datasets within an UML-framework.

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The Northern Rocky Mountains, home to the highest concentration of glaciers in the American West, are undergoing increased rates of climate warming, resulting in previously unseen ecological and hydrological outcomes. Globally, many glacier basins have experienced glacial recession to the threshold point of surpassing peak basin runoff, resulting in substantial decreases in local hydrological yield. Such findings call for models that do not alone examine glacial runoff but a complete examination of changes in the water budget. Alpine catchments are increasingly vulnerable to evapotranspirative losses due to climatic warming, and the rates of vegetation succession are often unable to keep up with the rate of warming. Basin scale analyses of glacial recession on streamflow are then confounded by ecohydrologic dynamics created by primary succession and the associated increase in evapotranspiration. In this study, I present a conceptual framework for modelling basin runoff in landscapes responding to paraglacial adjustment. The study goal was achieved by calibrating and running the Hydrologiska Byråns Vattenbalansavdelning (HBV) model in Swiftcurrent basin and investigating change across the basin water balance through baseflow analysis. The research findings indicate catchment scale changes in the timing and magnitude of the flow regime in the deglaciating Swiftcurrent basin, by employing HBV and empirical baseflow analysis. While most components of the water balance appear consistent across the study period, late summer baseflow values suggest the basin hydrology is undergoing changes, possibly a result of melt occurring earlier in the season. Ultimately, I advocate for an adaptable and accessible approach to understanding paraglacial basins by constructing an estimation of basin-scale water budgets. / Master of Science / Large scale trends in climate change are impacting a variety of ecosystems, especially alpine environments. Glacial recession has been well documented and studied in mountain chains across the globe, including the Rocky Mountains. Recession of these massive bodies of ice, which can be viewed as reservoirs of water in droughts or low flow months, has severe implications for society, the economy, and sensitive mountain environments. Furthermore, the new terrain exposed from beneath the melting glacier is dynamic and will undergo many adjustments geomorphically, in soil development, and ecologically as plants move up the glacier foreland. Ecological systems experiencing warming, deglaciation, and vegetation succession are not well understood and are complex environments due to the multiple inputs, interactions, and feedbacks. As such, this research examines how hydrologic conditions across a forty year period are changing in response to the complex feedbacks between glaciers, newly exposed terrain, and associated runoff. Through modeling and analysis, this study offers a method for understanding the water balance of Swiftcurrent basin in Glacier National Park, which can be used in other catchments experiencing similar changes.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第25261号 / 工博第5220号 / 新制||工||1996(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 田中 賢治, 教授 佐山 敬洋, 教授 市川 温 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Global warming leads to increased precipitation in the Arctic, as warmer air can carry more moisture. The consequence is that many arctic glaciers get steeper slopes over time as increased melt at their lower part causes thinning and increased solid precipitation in their upper regions leads to thickening of the glacier. Ice flow of glaciers is strongly controlled by the surface slope, where steeper slopes leads to increased ice flow. An altered flow regime of the glaciers can lead to unpredicted contributions to sea-level changes as more glacier ice is delivered to lower regions and eventually to the sea through calving of melt- runoff. Long-term measurements of ice-flow velocities are therefore crucial to receive a better understanding of how glaciers respond to climate changes in a temporal and spatial scale. This study investigates ice flow velocities measured over a period of 10 years between 2006 and 2015 on Nordenskiöldbreen, Svalbard. The poly-thermal outlet glacier is centrally located on Spitsbergen; the main island of the Svalbard archipelago (74N°,10°E /81N°,35°E). Ice-flow velocities are measured continuously using stand-alone single-frequency GPS receivers attached to 8 metal stakes along the central flow line of Nordenskiöldbreen. The Institute for Marine and Atmospheric research in Utrecht, the Netherlands (IMAU) has developed such GPS units to measure ice-flow velocities at low costs and all year-round. Ice flow velocities at the central-flow line of Nordenskiöldbreen for the period 2006-2016 are estimated to be between 40 and 60 m a-1. Results show that maximum ice flow velocities can reach up to 80 m a-1 and occur mainly in the beginning of July. The highest annual averaged velocity of 53.88 m a-1 was measured during summer 2014. Averaged ice-flow velocities show an increasing trend of about 1.78 m a-1 during summer seasons. Results are further compared with mass balance observations and temperature records to analyze how glacier systems respond to climate changes. / Klimatuppvärmningen bidrar till att glaciärer blir tunnare och smälter snabbare. Ett varmare klimat är också orsaken till att snöfall ökar då varmare luft kan transportera mer fuktighet. Konsekvensen blir att glaciärer i arktiska områden får brantare sluttningar. Brantare sluttningar leder sedan till att glaciärer rör sig snabbare. Om glaciärer plötsligt rör sig snabbare uppstår möjligheten att havsnivån också stiger snabbare. Uppsatsen undersöker is-hastigheten från Nordenskiöldbreen. Nordenskiöldbreen är en glaciär på Spetsbergen, Svalbard som går ut i Adolfbukta innerst Billesjorden. Hastigheten uppmättes med hjälp av 13 GPS-stationer på glaciärens yta, placerade mellan 800 och 1200 meter över havsnivån. GPS-stationerna är utvecklade av Institut för Marin- och Atmosfär-undersökningar i Utrecht, Holland (IMAU) för att mäta glaciärens hastighet året runt till låga kostnader. Sedan 1997 har Institutionen för geovetenskaper vid Uppsala Universitet utfört flera mätningar på Nordenskiöldbreen för att mäta massbalans, isrörelse och miljöförändringar. Massbalans mätningar har visat att glaciären fick brantare sluttningar över den senaste tio-års perioden. Uppsatsen analyserar trenden för isrörelse vid Nordenskiöldbreen över de senaste tio åren. Dessutom är resultanterna jämförda med massbalans-analyser och temperaturmätningar från Svalbard Flygplats. Jämförelsen hjälper att förstå hur glaciärens system reagerar på klimatförändringar. De uppskattade hastighetsresultaten visar att Nordenskiöldbreen rör sig med en medelhastighet av 45-53 meter per år. Isrörelse kan nå upp till 80 meter per år och är främst förekommande under juli månad när temperaturen är hög. Detta producerar då mer smältvatten vilket driver upp vattentrycket vid glaciärens botten och leder till basal glidning.

Regional paleoclimatic proxies and current local climate variables and were analyzed to reconstruct paleoglaciers in an effort to assess glacier change On Mount Rainier. Despite the dry and generally warm conditions (sea surface temperatures (SST) -0.15°C to +1.8°C relative to current temperatures), the previously documented McNeeley II advance (10,900 - 9,950 cal yr B.P.) was likely produced by air temperature fluctuations. The average SST record and the terrestrial climate proxies show cooling temperatures with continued dryness between McNeeley II and the Burroughs Mountain advance (3,442 - 2,153 cal yr B.P.). The paleoclimate during the Burroughs Mountain advance was both cool and warm (SST temperatures -0.55°C to +0.5°C) and was the wettest of the Holocene. A combination of statistical and deterministic equilibrium line altitude (ELA) models was used to produce Holocene ELAs between 1,735 -2,980 m. Glacial advances were predicted 10,990, 10,170, 9,260, 8,200, 6,490, 3,450 and 550 - 160 cal yr. B.P. Two glacier flow models were produced simultaneously to constrain glacial extent through the Holocene. Model I is based on current mass balance parameters and produced lengths for the Nisqually and Emmons glaciers 3.7 - 14.2 km and 4.2 - 17.1 km respectively. Glaciated area ranged from 26 to 327 km2. Model 2 is tuned to the Garda advance and produced lengths 2.6-10.6 km and 2.3-13.9 km. Glaciated area ranged from 11 to 303 km2. The first two advances were similar in elevation and GIS-modeled extent to McNeely II moraines. The following three advances were not detected in the geologic record. The 3,450 cal yr. B.P. advance was the largest of the late-Holocene (ELA 1,800 - 1,817 m) and was ~200 m lower than the geologic record. The ELAs of the Garda advance were modeled (1,944 - 1,983 m) and are similar to previous reconstructions. North-south spatial variations in glacial extent increase during periods of recession as the southern glaciers receive more ablation than northern glaciers. Early humans could have accessed the alpine environments as high as 1,730-2,980 m. The early Holocene glacial extent allowed the highest (2,980 m) 11,150 cal yr. B.P. and lowest (1,730 m) 10,990 cal yr. B.P. alpine access. Glacial retreat (2,727 m 10,400 cal yr. B.P.) was followed by an advance (1,929 m 10,170 cal yr. B.P.) and another retreat (2,951 m 10,050 cal yr. B.P.). Ice gradually descended and limited access to 1,820 m 6,490 cal yr. B.P. Glacial extents remained largely unchanged until the historic era when paleohumans would have had access to alpine environments at 2,000 m.