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AN ABSTRACT OF THE THESIS OF Elizabeth C. Geiger, for the Master's degree in Geology, presented on August 28, 2008, at Southern Illinois University Carbondale. TITLE: PALEOECOLOGY OF PLEISTOCENE GASTROPODS IN GLACIAL LAKE DEPOSITS IN SOUTHERN ILLINOIS/MISSOURI MAJOR PROFESSOR: Dr. Scott Ishman During the Pleistocene Epoch in the central Midwest United States multiple glaciations and interglaciations occurred in response to the advance and retreat of glaciers. This study focused on the Illinoian and Wisconsinan glaciations, which are separated by the Yarmouthian and Sangamonian interglacials. The advance of glaciers during glacial stages caused major rivers and their tributaries to aggrade creating slackwater lakes in many tributary valleys to the Mississippi River. Gastropod assemblages, found in glacial lake deposits, were used to interpret paleoecology during major glacial advances. Gastropods were collected from four sites in southern Illinois and Missouri to compare the Illinoian and Wisconsinan glaciations to one another, as well as to compare similar aged glacial lake deposits. This study identified forty-eight gastropod species, which were analyzed using statistical procedures. Hierarchical cluster analyses resulted in the identification of gastropod assemblages that were interpreted using habitat classifications. The results indicate specific similarities and differences between the Illinoian and Wisconsinan glaciations regarding environmental and climatic conditions.

No abstract was provided. / Thesis / Bachelor of Arts (BA)

This thesis investigates the origin, sedimentological characteristics, and paleoglacial significance of large latero-frontal moraines and moraine-dammed glacial lakes and their potential to generate glacial lake outburst flood (GLOF) events in the Cordillera Blanca, Perú and Iceland. This topic is particularly important as the potential for GLOF events in high altitude regions is increasing as ongoing global climate warming causes rapid glacier recession and the growth of lakes impounded by unstable moraines. The first chapter of this thesis introduces the characteristics of moraine dammed lakes and GLOFs and provides details of the study areas in Perú and Iceland that were selected for this work (Chapter 1). Chapter 2 investigates the glacial history of the Cordillera Blanca, Perú through the compilation, mapping, and analysis of dated moraines in the region. The formation of moraines by different glaciers in the same region at approximately the same time is interpreted to indicate a period of regional climate conditions that were favourable for glacier expansion and/or equilibrium. Six stages of glacial activity are identified from this analysis, ranging in age from older than 35 thousand years (Stage 1) to modern (Stage 6). The third chapter of this thesis identifies the geomorphic and sedimentologic characteristics of a moraine-dammed supraglacial lake (Llaca Lake) in the Cordillera Blanca, Perú. The combined use of imagery collected with an uncrewed-aerial vehicle (UAV), field sedimentological observations and geomorphological mapping allowed the creation of a landsystem model that summarizes the current geomorphic and sedimentologic environment of Llaca Lake (Chapter 3). This is the first study to describe the landform-sediment assemblages in a tropical moraine-dammed supraglacial lake and provides a framework for further landsystem analysis of growing supraglacial lakes that are at risk of GLOF events. The fourth chapter of this thesis describes the sedimentary architecture of the eastern lateral moraine of Gígjökull in southern Iceland. An uncrewed-aerial vehicle was used to acquire high resolution photographs of an exposure through the lateral moraine that allowed the identification of seven lithofacies types and three lithofacies associations. Documentation of the sedimentary architecture of the eastern lateral moraine of Gígjökull enhances understanding of moraine development and the identification of areas of hydrogeological weakness that can reduce the structural integrity of the moraine. The research findings presented in this thesis utilize a glacial sedimentological and geomorphological approach to investigating the relationship between current and past glacial processes in the study areas, and the role that these processes play in determining the characteristics and stability of large ice marginal moraines that impound glacial lakes. This work also furthers our understanding of the dynamic surface processes at work in high altitude regions such as the Cordillera Blanca. Identifying and determining the relationships between current and past processes, sediments and landforms will enhance understanding of the role of large moraines damming glacial lakes in other high-altitude regions such as the Himalayas, British Columbia, Patagonia, and New Zealand and the associated risk of GLOF events. / Thesis / Doctor of Science (PhD)

Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs) that have substantial impacts on regional social, environmental and economic systems increasing risk due to flooding of downstream communities. In this dissertation, two lakes with potential to generate GLOFs were studied, Imja Lake in Nepal and Palcacocha Lake in Peru. At Imja Lake, basic data was generated that allowed the creation of a conceptual model of the lake. Ground penetrating radar and bathymetric surveys were performed. Also, an inundation model was developed in order to evaluate the effectiveness of a project that seeks to reduce flooding risk by lowering the lake at least 3 meters. In Peru, a GLOF inundation model was created. Also, the vulnerability of the people living downstream in the City of Huaraz was calculated, and the impacts of an early warning system were evaluated. The results at Imja indicated that the lake deepened from 98 m in 2002 to 116 m in 2012. Likewise, the lake volume increased from 35.8 to 61.6±1.8 million m3 over the past decade. The GPR survey at Imja and Lhotse-Shar glaciers shows that the glacier is over 200 m thick in the center of the glacier. The modeling work at Imja shows that the proposed project will not have major impacts downstream since the area inundated does not reduce considerably unless the lake is lowered by about 20 m. In Huaraz, the results indicate that approximately 40646 people live in the potentially inundated area. Using the flow simulation and the Peru Census 2007, a map of vulnerability was generated indicating that the most vulnerable areas are near the river. Finally, the potential number of fatalities in a worst case GLOF scenario from Lake Palcacocha was calculated to be 19773 with a standard deviation of 1191 if there is no early warning system and 7344 with a standard deviation of 1446 people if an early warning system is installed. Finally, if evacuation measures are improved the number reduces to 2865 with a standard deviation of 462. / text

Spring flooding regularly occurs in the plain along the Assiniboine River’s low-lying terminus in eastern Manitoba as the river attempts to accommodate snowmelt drained from the central plains territory of North America. The annual insensitive response to the changing state of the river is a physical expression of competing understandings of time made manifest in the landscape. Can the consideration of time shift our understanding of flooding in the prairie context? How can a deep sense of time be expressed in our reaction to the design of the land? Shifting to thinking of a time-sensitive response to flooding, I aim to construct a hybrid cartography that addresses the relationship between observer and understanding fundamental to relevant critical projects in the landscape. This approach aims to understand the geographic and temporal context to reveal deep synchronicities ignored by rational approaches to both fluvial engineering and design. / May 2016

Glaciers and ice sheets covered extensive areas in the Northern Hemisphere during the last glacial period. Subsequently to the Last Glacial Maximum (LGM), they retreated rapidly and, except for Greenland and some other ice caps and glaciers, they vanished after the last glacial termination. This thesis examines the dynamics of deglacial environments by analysing the glacial geomorphological record with focus on the landforms created by glacial meltwater. The aims are (i) to evaluate the data available for mapping glacial meltwater features at the regional scale, and (ii) to demonstrate the potential of such features for regional ice retreat reconstructions in high-relief landscapes. Meltwater landforms such as ice-marginal meltwater channels, eskers, deltas and fossil glacial lake shorelines are used to infer former ice surface slope directions and successive positions of retreating ice margins. Evaluated high-resolution satellite imagery and digital elevation models reveal their potential to replace aerial photographs as the primary data for mapping glacial meltwater landforms. Following a methods study, reconstructions of the deglacial dynamics are carried out for central Transbaikalia, Siberia, Russia, and for the Cordilleran Ice Sheet (CIS) in central British Columbia, Canada, using regional geomorphological mapping surveys. Mapped glacial landforms in central Transbaikalia show evidence of a significant glaciation that possibly extended beyond the high mountain areas. Large glacial lakes were formed as advancing glaciers blocked rivers, and of these, Glacial Lake Vitim was the most prominent. Deglacial dynamics of the CIS reveals that the ice divide shifted to the Coast Mountains in north-central British Columbia and the eastern ice margin retreated towards the ice divide in late glacial time. This thesis demonstrates the potential to reconstruct ice retreat patterns and deglacial dynamics at regional scales by interpretation of the meltwater landform record. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Submitted. Paper 6: Manuscript.

In the context of changing climate retreat of mountain glaciers occurs at many places on the planet. One of the consequences is emergence or increase of the outburst risk at lakes situated in front of the glacier terminus. Flood caused by the glacial lake outburst often appear suddenly and can threaten settlements in lower parts of a valley. In the Kyrgyz mountains of Tien Shan there are about 350 lakes at risk of outburst, long-term monitored and dangerous locations are presented in this work. The highest attention is paid to Adygine area where several lakes of different genetic type and age can be found. The largest lake of the locality, the Upper Adygine lake, is subjected to more detailed survey aiming to asses its hydrological regime and to confirm or disprove speculation about outburst possibility of this lake. Keywords: glacial lake, hydrological regime, glacier retreat, Tien Shan, Kyrgyzstan

Eight dissolution caves from the Helderberg Plateau in Schoharie County, New York were studied to investigate unusual sediment packages previously interpreted to be deposits laid down during stagnant ice-cover conditions of the Wisconsin glaciation. The sediment package, consisting of white finely laminated silts and clays are overlain by coarse gravels, in turn overlain by dark silts and clays. Analysis of 63 sediment samples was inconclusive in terms of organic content, but indicated a higher degree of fine-grained calcite material in the white clays than in the overlying units. The caves with the white clays exist only within the footprint of Glacial Lake Schoharie, with lower elevation caves containing a thicker white clay sequence, a measure of the duration of lake cover. The sediment sequence represents glacial rock flour formed under stagnant lake conditions, overlain by outwash deposits emplaced during lake termination, and more recent sediment from soil-loss deposition.

The distribution of massive ground ice in the ground in Taylor Valley of the McMurdo Dry Valleys, Antarctica, is quite unknown, and could provide answers to questions such as where the ice comes from, if it has been affected and removed by proglacial lakes and how landscapes underlain by massive ground ice responds to climate change. It could also be a source for atmospheric information in the past and hence a key in climate research. The main goal with this project was therefore to map the distribution of massive ground ice mainly in Taylor Valley, but also in the adjacent Salmon Valley and Wright Valley, using ground penetrating radar to see how the distribution varied and if there was any spatial patterns. The technical computing programme MATLAB was used for editing of the raw radar data, merging of GPR profiles and digitalization of reflectors for possible massive ground ice and several compilations of different files. The data obtained from MATLAB was imported and interpreted using the geographic information system ArcGIS. A series of histograms showing the distribution of massive ground ice depending on the parameters elevation, slope and aspect were made by using the spreadsheet application Microsoft Excel. The results showed that the distribution of massive ground ice was more common at elevations up to 200 m, at the mouth of the valleys and also more frequent in Taylor Valley than in Wright Valley. There was a slightly higher amount of massive ground ice at northeast-east aspects, probably due to different incoming solar radiation. The lack of, or not that prominent, differences for slope and aspect can be due to lack of data, a not enough detailed digital elevation model or that it have existed for a too short period of time to display big differences caused by effects from these parameters. The higher frequency of massive ground ice in Taylor Valley can be due to a thicker sediment cover when compared with the situation in Wright Valley. The distribution of massive ground ice at different slopes seems to follow the distribution of radar measurements, whereas the origin of the massive ground ice and sediment cover can be responsible for the distribution across different elevations. The reason why massive ground ice still occurs despite the existence of Glacial Lake Washburn that previously occupied Taylor Valley could be that the glacial lake did not remain for a sufficiently long time to melt all the massive ice. Massive ground ice is very common in a zone that is believed to be very susceptible for future warming, which means that changes that already have been observed in areas rich in massive ground ice can continue to happen and changes in other areas with massive ice can be enabled. The ice can thus play a major role in the development of the landscape in the McMurdo Dry Valleys depending on the amount of warming. / Markis kan hittas i mark som har temperaturer under 0°C under åtminstone 2 år i följd och därav klassas som permafrost, skillnaden mellan markis och permafrost är däremot att permafrost inte behöver vara just is utan kan enbart vara kall mark. För att markis ska klassas som massiv is så ska andelen is i marken vara minst 250 % jämfört med vikten på torr jord. Utbredningen av sådan massiv is i Taylor Valley i McMurdos torrdalar på Antarktis är inte helt känd, och kunskapen om att veta vart den finns (om den finns) skulle kunna ge svar på frågor som vart den kommer ifrån, om den har påverkats och smält bort av isuppdämda sjöar och hur landskap som är grundade av massiv markis påverkas av klimatförändringar. Isen skulle även kunna vara en informationskälla för tidigare atmosfäriska förhållanden. Huvudsyftet med detta arbete var därför att kartlägga utbredningen av massiv is främst i Taylor Valley, men även i de närliggande dalarna Salmon Valley och Wright Valley, och undersöka hur utbredningen varierar beroende på olika landskapsegenskaper som påverkar dess förekomst. Datorprogrammet och programspråket MATLAB användes för att editera rådatat från radar-mätningarna i området, samt för att sammanföra och digitalisera horisonter för möjlig massiv markis i radarfigurerna och för ett antal sammanställningar av olika filer. Data erhållet från MATLAB importerades till det geografiska informationssystemet ArcGIS där det kunde visualiseras i kartor och tolkas. Ett antal histogram skapades i kalkylprogrammet Microsoft Excel för att visa frekvensen av massiv markis vid olika höjder, sluttningsvinklar och olika väderstrecksriktningar. Resultaten visade att det var mer vanligt med massiv is höjder upp till 200 m, vid mynningarna av dalarna samt i Taylor Valley jämfört med Wright Valley. Det var en aning mer vanligt med massiv markis vid nordöst-östliga sluttningsriktningar, vilket antagligen beror på olika mängder inkommande solstrålning till de olika riktningarna. Avsaknaden av, eller inte så märkbara, skillnader för olika sluttningsvinklar och riktningar kan bero på att mängden data var för liten, att höjdkartan inte var tillräckligt detaljerad eller att isen inte har funnits tillräckligt länge för att bli påverkad av dessa parametrar. Anledningen till att det finns mer massiv markis i Taylor Valley än i Wright Valley kan vara att det skyddande sedimenttäcket är tunnare i Wright Valley än i Taylor Valley. Frekvensen av massiv markis vid olika sluttningsvinklar verkar bero på det totala antalet mätningar gjorda, fler mätningar leder till en högre frekvens av markis, medan dess ursprung samt det antagna tunnare sedimenttäcket på högre höjder kan vara anledningen till de olika frekvenserna av massiv markis vid olika höjder. Anledningen till varför det fortfarande finns massiv markis trots existensen av den isuppdämda sjön Washburn som tidigare fanns i Taylor Valley, och att isen således inte helt har smält bort på grund av sjön, kan vara att den fanns under en för kort tid så att de långsamma termodynamiska processerna som skulle orsaka smältningen inte hann agera tillräckligt länge för att smälta all is. Den massiva markisen är vanlig i en zon som tros vara väldigt mottaglig för framtida uppvärmning, vilket betyder att landskapsförändringar som redan har observerats i områden med mycket massiv markis kan fortsätta att ske samtidigt som andra områden med massiv markis kan börja förändras. Isen kan därför spela en stor roll i landskapsutvecklingen i McMurdos torrdalar beroende på hur mycket varmare det blir i området.