Coastal zones are hotspots of global environmental changes. Worldwide, coastal environments face multiple, interactive stressors caused by both natural and anthropogenic impacts on climatic, oceanographic, ecological, and socio-economic processes such as sea level rise, storm surges, hurricanes, land subsidence, and population growth. The coastal U.S. is highly vulnerable to many of these climate and human-induced stressors. Over the past three decades, sea levels have risen by about 0.1 m along the U.S. coasts, with an additional projected increase of 0.2 to 0.3 m by 2050, and up to 2.0 m by the end of the century. The rise in sea levels will cause tides and storm surges to reach further inland, significantly altering flood regimes in coastal cities. By 2050, potentially damaging coastal flooding is expected to occur ten times as often compared to a baseline for the start of the 21st century. Moreover, these changes along the U.S. coastlines vary regionally and locally due to either positive or negative changes in land elevation over time (i.e., vertical land motion (VLM)). Lowering of land elevation (i.e., land subsidence) exacerbates sea level rise and the risk of inundation along coastal zones, presenting significant security challenges to coastal ecosystems, infrastructure, and populations. These dynamic and interacting stressors necessitate continuous monitoring to inform effective mitigation and adaptation strategies. Earth observation data allows for accurate, high-resolution, and continuous measurements of changing coastline. Despite the increasing availability of Earth observation data, current methods for monitoring VLM along coastlines lack the necessary spatial resolution and continuous coverage to accurately assess localized surface elevation changes. In this dissertation, I introduce a framework to jointly invert interferometric synthetic aperture radar (InSAR) and global navigation satellite systems (GNSS) data to provide semi-continuous measurement (50 m spatial resolution) of VLM for the contiguous U.S. coasts from 2007 – 2020. Combining the VLM dataset with projected sea level rise using different scenarios, I estimate flood hazards exposure for 32 major U.S. coastal cities by 2050, demonstrating that current measurements and frameworks underestimate flood vulnerability in several cities by not accounting for local and regional high-resolution VLM data. Next, I evaluate the possible drivers of land subsidence, exploring the relationship between spatio-temporal dynamic VLM and groundwater withdrawal from aquifers in major U.S. cities. Additionally, I assess the hazards and risks of land subsidence to infrastructure and wetlands along U.S. coasts. Finally, I extend this analysis beyond the U.S. coastline, investigating how land subsidence is linked to the incessant occurrence of building collapses in Lagos, Africa's most populous coastal city. / Doctor of Philosophy / Coastal areas worldwide are under significant stress from both natural and human-made changes, including rising sea levels, flooding, storms, hurricanes, land sinking, and population growth. The U.S. coasts are particularly affected by these issues. Sea levels have risen significantly over the past few years, with further increases expected in the near future. As sea levels rise, tides and storm patterns will change; thereby altering the flood frequency and magnitude in coastal cities. Land sinking exacerbates the impact of sea-level rise and flooding, affecting people, buildings, and the natural environment in coastal cities. These factors change over time, so they must be constantly monitored to develop effective strategies for adaptation and mitigation. Here, I used satellite-based tools to monitor land changes over time, identifying areas where the land is sinking. I combined this information of where land is sinking with sea-level rise data to estimate the areas that will be vulnerable to flooding by 2050 in 32 U.S. coastal cities, including Boston (MA), New York (NY), Virginia Beach (VA), Charleston (SC), Miami (FL), New Orleans (LA), Galveston (TX), and San Diego (CA). I also examined the causes of land sinking, particularly how groundwater extraction can lead to land sinking and the risks this poses to buildings and the natural environment along the U.S. coasts. This research highlights the impact of climate change and human activities on the U.S. coasts and the importance of continuous monitoring to enhance coastal resilience against current and future challenges.

Increasing sea levels have the potential to place important portions of the infrastructure we rely on every day at risk. The transportation infrastructure relies on roads, airports, and seaports to move people, services, and goods around in an ever connected global economy. Any disturbances of the transportation modes have reverberating effects throughout the entire economic spectrum. The effects include delays, alterations of routes, and possible changes in the origin and destinations of services and goods. The purpose of this project is to develop an improved methodology for a sea level rise scenario vulnerability assessment model. This new model uses the groundwater elevation as a limiting factor for soil storage capacity in determining previously underestimated areas of vulnerability. The hope is that early identification of vulnerability will allow planners and government officials an opportunity to identify and either remediate or create alternative solutions for vulnerable land areas before high consequence impacts are felt. / by Thomas Romah. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

O Porto de Santos está localizado no litoral Paulista, na costa Sudeste do Brasil e é o maior e mais importante porto do país. Desde 1859 vem sofrendo adaptações e modernizações tanto em suas instalações físicas quanto em sua estrutura administrativa. As variáveis com as quais a Engenharia Civil deve lidar podem ser resumidas basicamente aos fenômenos naturais, pois estes determinam como serão projetadas e construídas as estruturas e instalações. Em projetos portuários, diversas características naturais devem ser mensuradas como, por exemplo, ventos, correntes marítimas, incidência de ondas, tipo de solo em que se encontra o porto, as temperaturas médias do local e, sobretudo, o nível do mar. Os mares e oceanos não possuem superfícies estáveis e apresentam cotas que estão em movimentos constantes. Estas variações se dão basicamente por ondas de curto ou longo período. A maré é uma onda de longo período que causa a variação diária do nível do mar. Atualmente é cada vez maior o interesse da comunidade científica pela temática relacionada às variações do nível do mar. Buscando contribuir com o tema, o presente estudo tem como objetivo principal a análise das variações do nível do mar no Porto de Santos ao longo dos últimos 60 anos, utilizando-se de dados coletados nos três marégrafos da região. Foi elaborada a média móvel desta série com a finalidade de detectar alguma variação significativa. A análise dos dados implicou que fossem considerados períodos de 18,61 anos, correspondentes ao intervalo do ciclo de precessão lunar, de modo a eliminar o efeito da variação astronômica no nível do mar. A elevação do nível máximo, médio e mínimo do mar no período de 1953 a 2008, apresentou uma elevação média de 2,5 mm/ano, resultado semelhante a outros estudos. Foram avaliados também o impacto da variação do nível do mar sobre as estruturas portuárias, indicando os efeitos da elevação nas estruturas, nos cais, nos aparelhos de defensa e ancoragem, nos equipamentos de descarga e outros. / Santos Harbor is at São Paulo\'s coast, in Brazil\'s southeast coast and it is the biggest and the most important port of the country. Since 1859 had been suffering adaptations and modernizations in its installations such as in its administrative structure. The variables that Civil Engineering has to deal with can be resumed basically to the natural phenomena because its determines how projected and built the structures will be. In docks projects, several natural characteristics must be measured, as example, winds, ocean currents, waves incidence, kind of soil that supports the harbor\'s structures, the local medium temperatures and, mainly the sea level. The seas and oceans doesn\'t have stables surfaces and shows levels that are in constant movements. These variations are products of short and long period waves. The tide is a long period wave that causes the daily sea level variation. Actually, the interest of the scientific community in sea level variation is increasing. Aiming to contribute with this theme, the present study has as main objective analyzing the sea level variations at Santos Harbor above the last 60 years, using data collected from three tidal gauges in the region. It was applied the moving average of the series to detect some significant variation. The data analysis demanded that the periods of 18,61 years, which corresponds to the interval of the moon precession cycles, was considered to purge the astronomic variation over the sea level. The maximum sea level, average and minimum sea level, in the period of 1953 and 2008 showed an average increase of 2.5 mm/year, which is similar to other studies. It was evaluated the impact of this sea level rise over the port\'s structures, showing the structural effects, over the docks; in the defense and anchorage equipment, unload equipment and others.

Sea level rise (SLR) is one of the most damaging impacts associated with climate change. The objective of this study is to develop a comprehensive framework to identify the spatial patterns of sea level in the historical records, project regional mean sea levels in the future, and assess the corresponding impacts on the coastal communities. The first part of the study suggests a spatial pattern recognition methodology to characterize the spatial variations of sea level and to investigate the sea level footprints of climatic signals. A technique based on artificial neural network is proposed to reconstruct average sea levels for the characteristic regions identified. In the second part of the study, a spatial dynamic system model (DSM) is developed to simulate and project the changes in regional sea levels and sea surface temperatures (SST) under different development scenarios of the world. The highest sea levels are predicted under the scenario A1FI, ranging from 71 cm to 86 cm (relative to 1990 global mean sea level); the lowest predicted sea levels are under the scenario B1, ranging from 51 cm to 64 cm (relative to 1990 global mean sea level). Predicted sea levels and SST's of the Indian Ocean are significantly lower than those of the Pacific and the Atlantic Ocean under all six scenarios. The last part of this dissertation assesses the inundation impacts of projected regional SLR on three representative coastal U.S. states through a geographic information system (GIS) analysis. Critical issues in the inundation impact assessment process are identified and discussed.

Five coastal sites have been studies on the Isle of Skye to investigate Late Devensian and Holocene relative sea level changes. In the field, detailed stratigraphical work, geomorphological mapping and levelling were undertaken and representatives cores were sampled. Detailed pollen and diatom analyses were undertaken in the laboratory and samples were submitted for radiocarbon assay where distinct pollen, diatom or lithostratigraphical changes were recorded. Loss on ignition analysis was also undertaken to ascertain the carbon content of the samples. The investigations have revealed that during the Late Devensian marine transgressions were experienced at two sites in southern Skye. These are thought to relate to readvances of the ice that arrested the isostatic recovery of the land, caused renewed isostatic depression and upon deglaciation, allowed marine waters to penetrate the sites. At Inver Aulavaig the transgression is thought to relate to the Wester Ross Readvance recorded in Wester Ross, Coll and Tiree and at Point of Sleat the transgression is thought to relate the Loch Lomond Readvance recorded extensively in Scotland. Relative sea level at Point of Sleat (southern Skye) then fell below an altitude of 4.13mOD at 10460+-50BP and remained low during the early Holocene until the Main Postglacial Transgression occurred. This transgression is recorded at three of the sites: at Inver Aulavaig (southern Skye) at 8850+-70BP where it had attained an altitude of at least 5.10mOD, at Peinchorran (eastern Skye) where it is thought to have been underway by 7980+-BP and attained an altitude of 4.49mOD and at Talisker Bay (western Skye) at 7790+-100BP where it had attained an altitude of -2.18mOD. At Ardmore Bay (northern Skye) it is thought that the Main Postglacial Transgression did not reach an altitude of 3.34mOD. It is possible that barrier formation at some of the sites accompanied the early states of the Mian Postglacial Transgression. It is thought that regression of the sea occurred between circa 6600 BP and circa 5400 BP and remained low until circa 4200 BP when a later rise in relative sea level took place at Peinchorran attaining a maximum altitude of 4.90mOD. A late Holocene transgression is also recorded at Point of Sleat at between circa 3800 BP and circa 2900 BP where it attained an altitude of greater than 4.13mOD and at Inver Aulavaig after circa 3200 BP where it attained an altitude of between 5.10-6.01mOD. It is unclear whether this episode of high relative sea level represents the diachronous nature of one late Holocene transgression or several fluctuations in relative sea level during the late Holocene. Following the late Holocene transgression, relative sea level fell until the present day. Comparison of the data obtained from Skye with the isobase maps and rheological models suggests that the isobases for the Main Lateglacial Shoreline (Firth et al., 1993) show a good fit in age and altitude but the rheological model of Lambeck (1993b) for 10500 BP requires modification. The isobases for the Main Postglacial Shoreline appear to lie circa 4m too high for the sites studied on Skye and the isobases produced for a late Holocene shoreline appear to be greatly in error (Firth et al., 1993). It is possible that the build up of ice during the Loch Lomond Stadial may have had a greater effect on crustal movements than previously thought and this may account for discrepancies identified in the isobase maps. The study of isolation basins and back-barrier environments has allowed an assessment of their potential in recording relative sea level changes. The use of isolation basins in areas devoid of estuarine sedimentation has been particualrly demonstrated. The vegetation reconstruction undertaken, suggests that variations do occur in coastal locations compared to sites further inland, although these are subtle. The dates obtained for the increase in taxa such as 'Corylus avellana' and 'Alnus' and the recording of anthropogenic indicators on the vegetation, agree with those previously obtained for Skye. The use of pollen analysis in verifying the radiocarbon dates obtained, particualrly for the Late Devensian, has been recognised and, combined with diatom analysis, has provided a comprehensive database from which to reconstruct past relative sea levels.

O Porto de Santos está localizado no litoral Paulista, na costa Sudeste do Brasil e é o maior e mais importante porto do país. Desde 1859 vem sofrendo adaptações e modernizações tanto em suas instalações físicas quanto em sua estrutura administrativa. As variáveis com as quais a Engenharia Civil deve lidar podem ser resumidas basicamente aos fenômenos naturais, pois estes determinam como serão projetadas e construídas as estruturas e instalações. Em projetos portuários, diversas características naturais devem ser mensuradas como, por exemplo, ventos, correntes marítimas, incidência de ondas, tipo de solo em que se encontra o porto, as temperaturas médias do local e, sobretudo, o nível do mar. Os mares e oceanos não possuem superfícies estáveis e apresentam cotas que estão em movimentos constantes. Estas variações se dão basicamente por ondas de curto ou longo período. A maré é uma onda de longo período que causa a variação diária do nível do mar. Atualmente é cada vez maior o interesse da comunidade científica pela temática relacionada às variações do nível do mar. Buscando contribuir com o tema, o presente estudo tem como objetivo principal a análise das variações do nível do mar no Porto de Santos ao longo dos últimos 60 anos, utilizando-se de dados coletados nos três marégrafos da região. Foi elaborada a média móvel desta série com a finalidade de detectar alguma variação significativa. A análise dos dados implicou que fossem considerados períodos de 18,61 anos, correspondentes ao intervalo do ciclo de precessão lunar, de modo a eliminar o efeito da variação astronômica no nível do mar. A elevação do nível máximo, médio e mínimo do mar no período de 1953 a 2008, apresentou uma elevação média de 2,5 mm/ano, resultado semelhante a outros estudos. Foram avaliados também o impacto da variação do nível do mar sobre as estruturas portuárias, indicando os efeitos da elevação nas estruturas, nos cais, nos aparelhos de defensa e ancoragem, nos equipamentos de descarga e outros. / Santos Harbor is at São Paulo\'s coast, in Brazil\'s southeast coast and it is the biggest and the most important port of the country. Since 1859 had been suffering adaptations and modernizations in its installations such as in its administrative structure. The variables that Civil Engineering has to deal with can be resumed basically to the natural phenomena because its determines how projected and built the structures will be. In docks projects, several natural characteristics must be measured, as example, winds, ocean currents, waves incidence, kind of soil that supports the harbor\'s structures, the local medium temperatures and, mainly the sea level. The seas and oceans doesn\'t have stables surfaces and shows levels that are in constant movements. These variations are products of short and long period waves. The tide is a long period wave that causes the daily sea level variation. Actually, the interest of the scientific community in sea level variation is increasing. Aiming to contribute with this theme, the present study has as main objective analyzing the sea level variations at Santos Harbor above the last 60 years, using data collected from three tidal gauges in the region. It was applied the moving average of the series to detect some significant variation. The data analysis demanded that the periods of 18,61 years, which corresponds to the interval of the moon precession cycles, was considered to purge the astronomic variation over the sea level. The maximum sea level, average and minimum sea level, in the period of 1953 and 2008 showed an average increase of 2.5 mm/year, which is similar to other studies. It was evaluated the impact of this sea level rise over the port\'s structures, showing the structural effects, over the docks; in the defense and anchorage equipment, unload equipment and others.

Flood risk increases with rising sea levels and coastal settlements need to adapt to this increasing risk. For that, hazard and risk assessments are an important step. Coastal floods have caused problems in Iceland in the past and are thought to do so in the future as well. Therefore, a coastal flooding risk as- sessment needs to be made for Iceland. A risk assessment is currently in the early steps of preparation and a fitting method needs to be developed. To facilitate the process, an overview of the methods used in neighbouring countries is provided here and the suitability of the methods for Iceland is discussed. Building on these methods, a coastal flood scenario is produced for both present and future conditions as a preliminary hazard assessment for the country. The scenario produced is an upper bound scenario, highly unlikely but still possible. As a result, flooded areas are mapped and areas that need to be studied further in regard to flood hazard and risk are identified. It is shown that hazard estimation can be per- formed for Iceland through scenario production and that scenario results can be used in risk assessments. / De nuvarande klimatförändringar i världen kommer påverka människor på många olika sätt. En av de många saker som förändras är havsnivån. Havsnivån har stigit allt snabbare sedan i början av 1900 talet och kommer nästan säkert att fortsätta stiga i flera århudraden. Förhöjda havsnivåer föl- jer ökad översvämningsrisk som vi måste anpassa oss efter (Church, Clark, et al., 2013). Därför är riskbedömningar, alltså systematiska förfarande för att värdera risk, viktiga så att passande förebyggande åtgärder kan användas för att minska negativa påverkan från havsöversvämningar. En bedömning av översvämningsrisk från havet fattas för Island men för närvarande förbereder Is- ländska Meteorologiska Byrån att genomföra en. En tillämplig method behövs hittas och för att un- derlätta arbetet beskrivas i denna rapport metoder för preliminära bedömningar av översvämningsrisk från några av Islands grannländer; Danmark, Norge, Sverige och Storbrittanien. I huvudsak använder alla dessa länder liknande metoder, även om de har olika fysiska förutsättningar. De använder statis- tiska återkomsttider från mareograf data och informationer om historiska översvämningar för att bedöma faran. Sårbarhet identifieras inom fyra sårbarhets klasser, ofta genom ett index. Till slut sammanställs faro- och sårbarhetskartor för att bedöma risken och utpeka områden med översvämningsrisk. Eftersom Island har inte tillräckligt mycket data för att använda samma metoder som grannländerna, produceras i den här rapporten ett scenario för att värdera översvämningsfaran. Scenariot bygger på idéer från grannländerna och ska vara osannolikt men möjligt. Det är beräknad för både nuvarande och framtida förhållanden. Genom att subtrahera landhöjden från scenario havsnivån är översvämningsdju- pet beräknat. Några områden vart vattnet sannolikt skulle flöda och måste vara grundligt forskade är identiferade. Många påverkande faktorer är inte inkluderade i scenariot och därför anger resultatet inte noggranna översvämningskartor utan grovt överblick över översvämningsfaran. Resultaten ger alltså en idé om vart faran från havsöversvämningar är som störst och i vilka områden framtidiga havsnivåförän- dringar kommer bli som största. De visar också att ett scenario kan användas för farobedömning på Island, som sen kan kombineras med sårbarhetsbedömning via en index för att bedöma översvämn- ingsrisken på samma sätt som i grannländerna.

Le niveau de la mer est une des variables climatiques essentielles dont la variabilité résulte de nombreuses interactions complexes entre toutes les composantes du système climatique sur une large gamme d'échelles spatiales et temporelles. Au cours du XXème siècle, les mesures marégraphiques ont permis d'estimer la hausse du niveau de la mer global entre 1,6 mm/an et 1,8 mm/an. Depuis 1993, les observations faites par les satellites altimétriques indiquent une hausse du niveau de la mer plus rapide de 3,3 mm/an. Grâce à leur couverture quasi-globale, elles révèlent aussi une forte variabilité du niveau de la mer à l'échelle régionale, parfois plusieurs fois supérieure à la moyenne globale du niveau de la mer. Compte tenu de l'impact très négatif de l'augmentation du niveau de la mer pour la société, sa surveillance, la compréhension de ses causes ainsi que sa prévision sont désormais considérées comme des priorités scientifiques et sociétales majeures. Dans cette thèse, nous validons d'abord les variations du niveau de la mer mesurées par la nouvelle mission d'altimétrie satellitaire, SARAL-AltiKa, en comparant les mesures avec celles de Jason- 2 et des marégraphes. Un autre volet de cette première partie de thèse a consisté à estimer les parts respectives des facteurs responsables des variations du niveau de la mer depuis 2003 en utilisant des observations issues de l'altimétrie satellitaire (missions altimétrique Jason-1, Jason-2 et Envisat), de la mission GRACE, et des profils de température et salinité de l'océan par les flotteurs Argo. Une attention particulière est portée à la contribution de l'océan profond non 'vue' par Argo. Nous montrons que les incertitudes dues aux approches du traitement des données et aux erreurs systématiques des différents systèmes d'observation nous empêchent encore d'obtenir des résultats précis sur cette contribution. Dans la deuxième partie de la thèse, en utilisant les données de reconstruction du niveau de la mer dans le passé, nous étudions la variabilité régionale du niveau de la mer et estimons sa hausse totale (composante régionale plus moyenne globale) de 1950 à 2009 dans trois régions vulnérables: l'océan Indien, la mer de Chine méridionale et la mer des Caraïbes. Pour les sites où l'on dispose de mesures du mouvement de la croûte terrestre par GPS, nous évaluons la hausse locale du niveau de la mer relatif (hausse du niveau de la mer totale plus mouvement de la croûte locale) depuis 1950. En comparant les résultats de ces trois régions avec une étude précédente sur le Pacifique tropical, nous constatons que le Pacifique tropical présente la plus forte amplitude des variations du niveau de la mer sur la période d'étude. Dans la dernière partie de la thèse, nous nous concentrons par conséquent sur le Pacifique tropical. Nous analysons les rôles respectifs de la dynamique océanique, des modes de variabilité interne du climat et du forçage anthropique sur les structures de la variabilité régionale du niveau de la mer du Pacifique tropical depuis 1993. Nous montrons qu'une partie importante de la variabilité régionale du niveau de la mer du Pacifique tropical peut être expliquée par le mouvement vertical de la thermocline en réponse à l'action du vent. En tentant de séparer le signal correspondant au mode de variabilité interne du climat de celui de la hausse régionale du niveau de la mer dans le Pacifique tropical, nous montrons également que le signal résiduel restant (c'est-à-dire le signal total moins le signal de variabilité interne) ne correspond probablement pas à l'empreinte externe du forçage anthropique. / Sea level is an integrated climate parameter that involves interactions of all components of the climate system (oceans, ice sheets, glaciers, atmosphere, and land water reservoirs) on a wide range of spatial and temporal scales. Over the 20th century, tide gauge records indicate a rise in global sea level between 1.6mm/yr and 1.8 mm/yr. Since 1993, sea level variations have been measured precisely by satellite altimetry. They indicate a faster sea level rise of 3.3 mm/yr over 1993-2015. Owing to their global coverage, they also reveal a strong regional sea level variability that sometimes is several times greater than the global mean sea level rise. Considering the highly negative impact of sea level rise for society, monitoring sea level change and understanding its causes are henceforth high priorities. In this thesis, we first validate the sea level variations measured by the new satellite altimetry mission, SARAL-AltiKa by comparing the measurements with Jason-2 and tide gauge records. We then attempt to close the global mean sea level budget since 2003 and estimate the deep ocean contribution by making use of observational data from satellite altimetry, Argo profiles and GRACE mission. We show that uncertainties due to data processing approaches and systematic errors of different observing systems still prevent us from obtaining accurate results. In the second part of the thesis, by making use of past sea level reconstruction, we study the patterns of the regional sea level variability and estimate climate related (global mean plus regional component) sea level change over 1950-2009 at three vulnerable regions: Indian Ocean, South China and Caribbean Sea. For the sites where vertical crustal motion monitoring is available, we compute the total relative sea level (i.e. total sea level rise plus the local vertical crustal motion) since 1950. On comparing the results from these three regions with already existing results in tropical Pacific, we find that tropical Pacific displays the highest magnitude of sea level variations. In the last part of the thesis, we therefore focus on the tropical Pacific and analyze the respective roles of ocean dynamic processes, internal climate modes and external anthropogenic forcing on tropical Pacific sea level spatial trend patterns since 1993. Building up on the relationship between thermocline and sea level in the tropical region, we show that most of the observed sea level spatial trend pattern in the tropical Pacific can be explained by the wind driven vertical thermocline movement. By performing detection and attribution study on sea level spatial trend patterns in the tropical Pacific and attempting to eliminate signal corresponding to the main internal climate mode, we further show that the remaining residual sea level trend pattern does not correspond to externally forced anthropogenic sea level signal. In addition, we also suggest that satellite altimetry measurement may not still be accurate enough to detect the anthropogenic signal in the 20 year tropical Pacific sea level trends.

Geomorphic features have been one of the major tools for sea-level change studies. The present work shows an example of sea-level change study on karst terrain in the tropics. Sea-level notches as well as flank margin caves were identified in the research area and their elevation measured. The time of formation of the sea-level indicators was constrained by lithology study and dating methods such as facies comparison and U-Th dating. Denudation and uplift were also studied for the same purpose. From this study it can be concluded that sea-level stands within the glacial cycle can cause the formation of flank margin caves and that the position of these sea-level stands can be determined. The research area was estimated to have cumulatively uplifted ~22 m in the past 125 ka years (~0.18 mm/yr) while the surface has been denuded some 8 m in the same span of time (~0.064 mm/yr).

Throughout the Holocene, appreciable changes in bathymetry are hypothesized to have resulted in large changes to tidal datums in coastal and estuarine areas. An understanding of tidal change is an important contribution to the knowledge of relative historical sea-level change and future coastal planning. To test this hypothesis, the Advanced Circulation (ADCIRC) model was used, with representative bathymetric grids based on glacial isostatic adjustment models and semi-empirical sea level rise predictions, in order to model the time-varying tidal behavior of the Delaware Bay. Model runs were conducted at various time slices between 10,000 years before present and 300 years into the future on high resolution grids that allowed for inundation moving forward in time. Open boundary tidal forcing was held constant in time to highlight the effect of the changing regional bathymetry. With each change in sea level, the shape of the Delaware Bay was considerably altered, leading to changes in the tides. Resonance and shallow water dissipation appeared to be the primary mechanisms behind these changes. Results showed that tidal ranges have nearly doubled in the upper Delaware Bay over the past 3000 years, while decreasing in the lower bay by 8%. Tidal range change represents a possible correction to past sea level rise estimates from the geologic record. Scenarios incorporating future sea level predictions primarily showed a small decrease in tidal range, potentially impacting future water levels and tidal sediment transport. Trends modeled were consistent with field measurements of relative change over similar time periods. / Graduation date: 2012