Regional Sea Level Rise Research Articles

Assessing the impacts of climate change on the vulnerability of coastal aquifers to the seawater intrusion

In most coastal areas, groundwater is affected by saltwater intrusion. Climate change effects, such as the sea-level rise and rainfall change are the climatic factors affecting the saltwater intrusion into groundwater. This study examines the vulnerability of the Abdan-Lamidan coastal aquifer to the intrusion of Persian Gulf saline waters under different hydrological conditions. First, the SIMCLIM model was used to calculate the regional sea-level rise of the Gulf under 24 future AOGCMs projections. The results showed that the increase in water level under the ensemble of AOGCM models and two RCP2.6 and RCP8.5 scenarios is 6.7 and 7.8 cm in 2050 compared to 2013. Then, the GALDIT vulnerability index was used to assess the vulnerability of the aquifer under the current condition and future scenarios. The results showed that parts of the aquifer that are currently at lower levels would be more vulnerable to sea-level rise in the future periods.

Monitoring Coastal Evolution and Geomorphological Processes Using Time-Series Remote Sensing and Geospatial Analysis: Application Between Cape Serrat and Kef Abbed, Northern Tunisia

The monitoring of coastal evolution (coastline and associated geomorphological features) caused by episodic and persistent processes associated with climatic and anthropic activities is required for coastal management decisions. The availability of open access, remotely sensed data with increasing spatial, temporal, and spectral resolutions, is promising in this context. The coastline of Northern Tunisia is currently showing geomorphic process, such as increasing erosion associated with lateral sedimentation. This study aims to investigate the potential of time-series optical data, namely Landsat (from 1985–2019) and Google Earth® satellite imagery (from 2007 to 2023), to analyze shoreline changes and morphosedimentary and geomorphological processes between Cape Serrat and Kef Abbed, Northern Tunisia. The Digital Shoreline Analysis System (DSAS) was used to quantify the multitemporal rates of shoreline using two metrics: the net shoreline movement (NSM) and the end-point rate (EPR). Erosion was observed around the tombolo and near river mouths, exacerbated by the presence of surrounding dams, where the NSM is up to −8.31 m/year. Despite a total NSM of −15 m, seasonal dynamics revealed a maximum erosion in winter (71% negative NSM) and accretion in spring (57% positive NSM). The effects of currents, winds, and dams on dune dynamics were studied using historical images of Google Earth®. In the period from 1994 to 2023, the area is marked by dune face retreat and removal in more than 40% of the site, showing the increasing erosion. At finer spatial resolution and according to the synergy of field observations and photointerpretation, four key geomorphic processes shaping the coastline were identified: wave/tide action, wind transport, pedogenesis, and deposition. Given the frequent changes in coastal areas, this method facilitates the maintenance and updating of coastline databases, which are essential for analyzing the impacts of the sea level rise in the southern Mediterranean region. Furthermore, the developed approach could be implemented with a range of forecast scenarios to simulate the impacts of a higher future sea-level enhanced climate change.

Ice Darkening on Turner Glacier in Auyuittuq National Park, Nunavut

The glaciers of the Canadian Arctic are currently the third largest contributor to global sea level rise due to enhanced Arctic warming driving increased glacier melt and runoff (Zemp et al., 2019). Recent modelling suggests that the glaciers of the southern Qikiqtaaluk region, specifically Baffin and Bylot Islands, are 70% more sensitive to 1°C of warming (Brice et al., 2018). However, these studies lack field-based data to contextualize the drivers of glacier change in this region. Light absorbing particles (LAPs) such as dust, ash, and algae lower the albedo of snow and ice, which is the fraction of light a surface reflects, leading to an increase in the absorption of incoming radiation (Aubry-Wake et al., 2022). On glaciers in western Canada (Engstrom et al., 2022), the European Alps (Di Mauro et al., 2020) and south-western Greenland (Cook et al., 2020), positive feedback mechanisms have been discovered where summer snow and ice melt, augmented by LAPs, leads to the localized release of nutrients in ice and the subsequent enhanced growth of algae. Preliminary remote sensing analysis revealing a dark purple hue on glaciers in the Akshayuk Pass region of Auyuittuq National Park in Baffin Island, NU indicate these processes are likely occurring. The question of how this phenomenon is impacting glacier albedo, and therefore glacier melt which has implications for mass balance and regional sea level rise in the Canadian High Arctic has yet to be answered. Field-based sampling of LAPs on Turner Glacier, characterized through light microscopy and scanning electron microscopy, combined with in-situ hyperspectral spectroradiometer measurements (320nm-1100nm) of the sampled LAPs, and fine resolution (1cm) UAV surveys of sampling sites, are integral to develop a field-calibrated remote sensing approach to monitor LAP accumulation on the glacier surface and to assess the associated melt potential.

Building Disaster Resilience in Thousand Islands (Indonesia): Unlocking Climate Adaptation Strategies to Navigate Sea Level Rise in Coastal Regions while Safeguarding Crop Productivity and Local Biodiversity

Building Disaster Resilience in Thousand Islands (Indonesia): Unlocking Climate Adaptation Strategies to Navigate Sea Level Rise in Coastal Regions while Safeguarding Crop Productivity and Local Biodiversity

Causes and multiyear predictability of the rapid acceleration of U.S. Southeast Sea level rise after 2010

The rate of sea level rise (SLR) along the Southeast Coast of the U.S. increased significantly after 2010. While anthropogenic radiative forcing causes an acceleration of global mean SLR, regional changes in the rate of SLR are strongly influenced by internal variability. Here we use observations and climate models to show that the rapid increase in the rate of SLR along the U.S. Southeast Coast after 2010 is due in part to multidecadal buoyancy-driven Atlantic meridional overturning circulation (AMOC) variations, along with heat transport convergence from wind-driven ocean circulation changes. We show that an initialized decadal prediction system can provide skillful regional SLR predictions induced by AMOC variations 5 years in advance, while wind-driven sea level variations are predictable 2 years in advance. Our results suggest that the rate of coastal SLR and its associated flooding risk along the U.S. southeastern seaboard are potentially predictable on multiyear timescales.

The dominant modes of recent sea level variability from 1993 to 2020 in the China Seas

A better understanding of internal climatic variability is essential for estimating and predicting regional sea level rise in the coming decades. Based on the satellite altimeter data, the cyclostationary empirical orthogonal function (CSEOF) analysis is used to extract and examine the seasonal signal, trend, El Niño-Southern Oscillation (ENSO)-related, and low-frequency mode of sea level anomaly in the China Seas from 1993 to 2020. The interannual changes in the annual cycle of sea level were significantly influenced by the mean surface pressure and the 10-m zonal wind component. Furthermore, strong El Niño events (1997/1998) can significantly affect seasonal fluctuations through precipitation and runoff. By recombining the loading vector and principal component time series of the trend mode, we estimate the sea level trends to be about 3.63 ± 0.37 mm/yr. The South China Sea, followed by the Yellow Sea, is where ENSO's effects on sea level fluctuations are most noticeable. The 2015–2016 El Niño, which was a combination of the Central Pacific (CP) ENSO Eastern Pacific (EP) ENSO, had average sea levels that were much lower than those of the 1997–1998 (CP ENSO) and 2009–2010 (CP ENSO). The Pacific Decadal Oscillation (PDO) can significantly affect the low frequency mode, but other sources also contribute to this mode. The South China Sea, especially to the west of Luzon Island, exhibits the highest level of variability in the low-frequency mode. Finally, our work shows that, in contrast to global or oceanic scales, regional CSEOF analysis does, in fact, capture regional sea level variability more accurately and detailed.

Policy planning and practical implementations of coastal adaptation strategies to reduce the impact of sea level rise in the coastal region of Kanyakumari District, Tamil Nadu, India

Coastal adaptation is a scientific process, and social, economic, and political adjustment of coastal management policies to minimize the climate impact and increase the resilience in the coastal system. The Kanyakumari coastal region encompasses industrial, ecological, residential and tourist hotspots with high sensitivity for the impact of sea level rise. We used mixed policy tools to evaluate the impact in the coastal region and develop adaptation strategies which are integrated into existing management. To be an effective implementation of adaptation policy, we propose five guiding principles: (i) Develop a coastal settlement management plan for accelerated sea level rise in each fishing hamlet by incorporating the plan into sub district planning. (ii) Entitle a Multipurpose Cyclone Shelter (MCS) in each fishing hamlet and each one access for refugee seekers during a cyclone and later for internally displaced persons (IDPs). (iii) Develop a database system at village level to set up the coastal adaptation policies against sea level rise and a database system should be update time to time (climate, population, migrants, vulnerability data). (iv) Setup an Agricultural Conservation Practices (ACP) and Wetland Reclamation Plan (WRP) in the wetland-rich coastal plain region. (v) Practical approaches to linking the coastal adaptation plan in the study area to the Sustainable Development Goals (SDGs) targets and indicators are proposed.

Floating Ports as Support for Port Relocation Measures on Sea Level Rise

Ports are one of the structures where the effects of global warming are most severe and intense in atmospheric, oceanic, and geographical terms. According to the Intergovernmental Panel on Climate Change (IPCC)'s assessment reports, although it is possible to slow down global warming by reducing greenhouse gas (GHG) emissions, it is not foreseen to stop global warming and sea level rise (SLR) in any scenario. The rising sea level, an inevitable consequence of global warming, is a clear threat to conventional port facilities. In summary, SLR triggered by climate change, which is today's hot topic, may cause conventional port infrastructures to be flooded and lose their functionality. To cope with this threat, port facility planning, and design stages must be carried out by referring to the updated threshold values in Shared Socioeconomic Pathway (SSP) scenarios defined by the Working Groups of the IPCC. However, the uncertainty about the scale, timing, and location of SLR makes definitive solution-oriented approaches more prominent. One of these approaches is floating port structures. This study aims to reveal the role of floating port structures in the implementation of the relocation measure emphasized in the IPCC Sixth Assessment Report (AR6) for conventional ports under the threat of SLR. Initially, in this study, regions with higher SLR risk were identified by considering SSP scenarios contributed by Sixth Phase of the Coupled Model Intercomparison Project (CMIP6) data. Afterwards, the dynamic downscaling model was used to determine the regions with higher regional sea level rise (RSLR) risk and the Marine Traffic database was used to determine the ports in these regions. Thus, it is evaluated whether floating ports can be a suitable alternative in the relocation decision of ports under SLR risk. It is expected that maritime transport will be maintained at adequate security and operational levels by revealing the pros and cons of floating ports.

A Review of the Contribution of Satellite Altimetry and Tide Gauge Data to Evaluate Sea Level Trends in the Adriatic Sea within a Mediterranean and Global Context

The relatively new sea level satellite altimetry and secular coastal tide gauge data made the reconstruction of sea levels on regional and global scales possible about one century back. Due to better estimations of the Earth’s crustal, glacial, tectonic, and other possible motion biases in tide gauge data, some additional improvements can be expected in sea level reconstructions, analysis, and predictions. A more detailed review of published sea level-related results was conducted for the Eastern Adriatic coast, including the operation of the tide gauge network and data processing, crustal movement estimations, and the establishment of a new reference height system in Croatia, based on five tide gauge sea level data. It was shown that sea level variation and trend-related indicators are spatially homogeneous, especially on a sub-Adriatic scale. The regional Adriatic Sea mean sea level rise rate of +2.6 mm/year for the satellite altimetry era (1993–2019) is less than the global mean sea level (GMSL) rise rate of +3.3 mm/year for the period of 1993–2022. Several empirical methods for GMSL projections and expected IPCC (Intergovernmental Panel on Climate Change) assessments until the end of the 21st century are considered.

Eddy-driven sea-level rise near the frontal region off the east coast of the Korean peninsula during 1993–2020

IntroductionUnderstanding the underlying dynamics of regional sea-level rise (SLR), which often deviates from global trends, is crucial for mitigating and adapting to the impacts of severe climate change. This study investigated the causes of high regional SLR rates (> 6.0 mm yr-1) around the frontal region near Ulleung Island in the southwestern East/Japan Sea (EJS). Despite exhibiting rates higher than the global average (3.1 mm yr-1) from 1993 to 2020, the reasons for these higher rates in this region have not been clearly elucidated.MethodsWe aimed to clarify the quantitative effect of the long-term variations of the Ulleung Warm Eddy (UWE) on the high SLR rates near Ulleung Island based on satellite altimetry and ship-based hydrographic data.ResultsDuring this period, the temperature within the UWE increased, particularly at the temperature-homogeneous layer of approximately 200 m, the lower boundary of the UWE deepened, and the eddy duration per year increased, resulting in high SLR rates within the eddy owing to the steric height rise. The long-term variations in the internal temperature and vertical thickness of the UWE had significantly comparable impacts on SLR rates, with the duration being less influential. The SLR rates by integrating all long-term variations in the UWE (7.6 mm yr-1) quantitatively explained the high long-term SLR rates at Ulleung Island (7.0 mm yr-1).DiscussionThe increasing temperature within the UWE was attributed to the rising temperature of water flowing through the southwestern strait (Korean Strait) in late fall, and the deepening lower boundary and the increasing duration of the UWE resulted from the increased horizontal temperature gradients near the front, leading to enhanced baroclinic instability in the subsurface layers. Our findings suggest that long-term variations in mesoscale eddies can significantly influence the regional SLR rates, deviating substantially from the global average in the frontal region.

Biophysical Drivers of Coastal Treeline Elevation

AbstractSea level rise is leading to the rapid migration of marshes into coastal forests and other terrestrial ecosystems. Although complex biophysical interactions likely govern these ecosystem transitions, projections of sea level driven land conversion commonly rely on a simplified “threshold elevation” that represents the elevation of the marsh‐upland boundary based on tidal datums alone. To determine the influence of biophysical drivers on threshold elevations, and their implication for land conversion, we examined almost 100,000 high‐resolution marsh‐forest boundary elevation points, determined independently from tidal datums, alongside hydrologic, ecologic, and geomorphic data in the Chesapeake Bay, the largest estuary in the U.S. located along the mid‐Atlantic coast. We find five‐fold variations in threshold elevation across the entire estuary, driven not only by tidal range, but also salinity and slope. However, more than half of the variability is unexplained by these variables, which we attribute largely to uncaptured local factors including groundwater discharge, microtopography, and anthropogenic impacts. In the Chesapeake Bay, observed threshold elevations deviate from predicted elevations used to determine sea level driven land conversion by as much as the amount of projected regional sea level rise by 2050. These results suggest that local drivers strongly mediate coastal ecosystem transitions, and that predictions based on elevation and tidal datums alone may misrepresent future land conversion.

A framework for coastal flood hazard assessment under sea level rise: Application to the Persian Gulf

Coastal areas are of paramount importance due to their pivotal role in facilitating a wide range of socio-economic activities and providing vital environmental services. These areas, as the meeting points of land and sea, face significant risks of flooding due to the ongoing rise in sea levels caused by climate change. Additionally, they are susceptible to extreme events like king tides and large waves in the future. This paper introduces a framework for estimating the extreme total water level (TWL) by considering the effects of regional sea level rise (RSLR) resulting from a warming climate under RCP 8.5. It also incorporates the contributions of high tides, 100-year storm surge, and 100-year wave setup and run-up. The proposed framework is utilized to evaluate the occurrence of extreme coastal flooding along the Persian Gulf coast of Iran, an area that is home to significant industries in the country. The results offer an estimated increase of RSLR by 0.23 m from 2020 to 2050 considering an ensemble of climate model projections. Extreme wave setup values are estimated to range between 0.19 and 0.66 m, while storm surge is projected to vary from 0.4 to 1.44 m across the studied coastline. These together yield in a projected extreme TWL along the coastline within the range of 3.18 and 3.90 m above the current sea level. This significant increase in sea level could lead to the inundation of approximately 513 km2 of low-lying coastal land, which accounts for about 16% of the studied domain and could pose serious flooding threat to the people and their assets in this region. Finally, relative ranking of flooded zones (i.e., 6 zones) helps determine the areas with higher chance of flood exposure, at which investment in flood mitigation measures should be prioritized.

Suboptimal Rootzone Growth Prevents Long Island (NY) Salt Marshes from Keeping Pace with Sea Level Rise

Salt marsh habitat loss and conversion are well documented across the marine-coastal district of New York. Regionally, these losses are characterized by marsh edge erosion, ditch and creek widening, internal ponding, and conversion from irregularly flooded marsh to regularly flooded marsh and intertidal mudflats. These changes in horizontal extent and shifts in vegetation composition suggest that NY’s salt marshes may not be keeping pace with sea level rise. To evaluate elevation building processes, deep rod surface elevation tables, marker horizons, and shallow rod surface elevation tables (SET-MHs and shallow RSETs) were installed as a network across Long Island, NY. Contributions of surface, shallow subsurface, and deeper processes to overall elevation changes were observed from 2008 to 2022. Using a linear mixed model approach, surface accretion, shallow subsurface rootzone growth, and deeper below-ground processes were evaluated against regional sea level rise, nutrient loading, and marsh area trends. We found that marshes on Long Island are not keeping pace with sea level rise because they lack vertical elevation growth within the rootzone. Optimizing conditions for belowground growth of native salt marsh plants and preservation of organic matter within the peat matrix is key for restoring salt marshes to a positive elevation trajectory relative to sea level rise. Much like a retirement savings account, knowing whether our marshes are increasing in elevation is important, but understanding the full suite of deposits and withdrawals is critical for managing this valuable resource for the future.

Can we trust projections of AMOC weakening based on climate models that cannot reproduce the past?

The Atlantic Meridional Overturning Circulation (AMOC), a crucial element of the Earth's climate system, is projected to weaken over the course of the twenty-first century which could have far reaching consequences for the occurrence of extreme weather events, regional sea level rise, monsoon regions and the marine ecosystem. The latest IPCC report puts the likelihood of such a weakening as 'very likely'. As our confidence in future climate projections depends largely on the ability to model the past climate, we take an in-depth look at the difference in the twentieth century evolution of the AMOC based on observational data (including direct observations and various proxy data) and model data from climate model ensembles. We show that both the magnitude of the trend in the AMOC over different time periods and often even the sign of the trend differs between observations and climate model ensemble mean, with the magnitude of the trend difference becoming even greater when looking at the CMIP6 ensemble compared to CMIP5. We discuss possible reasons for this observation-model discrepancy and question what it means to have higher confidence in future projections than historical reproductions. This article is part of a discussion meeting issue 'Atlantic overturning: new observations and challenges'.

Thermosteric and dynamic sea level under solar geoengineering

The IPCC sixth assessment report forecasts sea level rise (SLR) of up to 2 m along coasts by 2100 relative to 1995–2014 following business as usual (SSP585) scenarios. Geoengineering may reduce this threat. We use five Earth System Models simulations of two different solar geoengineering methods (solar dimming and stratospheric sulfate aerosol injection), that offset radiative forcing differences between SSP585 “no-mitigation” and the modest mitigation SSP245 greenhouse gas scenarios, to analyze the impact on global mean thermosteric and dynamic regional sea levels. By 2080–2099, both forms of geoengineering reduce global mean thermosteric sea level by 36–41% (11.2–12.6 cm) relative to SSP585, bringing the global mean SLR under SSP585 in line with that under SSP245, but do not perfectly restore regional SLR patterns. Some of the largest reductions (∼18 cm) are on densely populated coasts of eastern Northern America and Japan and along vulnerable Arctic coastal permafrost.

A process-based assessment of the sea-level rise in the northwestern Pacific marginal seas

Because regional sea-level rise can threaten coastal communities, understanding and quantifying the underlying process contributing to reginal sea-level budget are essential. Here, we assessed whether the regional sea-level rise on the northwestern Pacific marginal seas can be closed with a combination of observations and ocean reanalyses over 1993–2017, as well as with independent observations from in situ profiles including Argo floats and satellite gravity measurements since 2003. The assessment represents that the major contributions come from the land ice melt and sterodynamic components, while the spatial pattern and interannual variability are dominated by sterodynamic effect. The observation-based estimate further shows that along continental shelves, sterodynamic sea-level changes are substantially induced by ocean mass redistribution due to changes in ocean circulation. This result highlights the ocean mass change between the deep ocean and shallow marginal seas, which plays a role in driving regional sea-level rise and variability.

Challenges towards the Sustainability and Enhancement of the Indian Sundarban Mangrove's Blue Carbon Stock.

The Sundarban is the world's largest contiguous mangrove forest and stores around 26.62 Tg of blue carbon. The present study reviewed the factors causing a decline in its blue carbon content and poses a challenge in enhancing the carbon stock of this region. This review emphasized that recurrent tropical cyclones, soil erosion, freshwater scarcity, reduced sediment load into the delta, nutrient deficiency, salt-stress-induced changes in species composition, mangrove clearing, and anthropogenic pollution are the fundamental drivers which can potentially reduce the total blue carbon stock of this region. The southern end of the Ganges-Brahmaputra-Meghna Delta that shelters this forest has stopped its natural progradation due to inadequate sediment flow from the upper reaches. Growing population pressure from the north of the Sundarban Biosphere Reserve and severe erosion in the southern end accentuated by regional sea-level rise has left minimal options to enhance the blue carbon stock by extending the forest premises. This study collated the scholarly observations of the past decades from this region, indicating a carbon sequestration potential deterioration. By collecting the existing knowledge base, this review indicated the aspects that require immediate attention to stop this ecosystem's draining of the valuable carbon sequestered and, at the same time, enhance the carbon stock, if possible. This review provided some key recommendations that can help sustain the blue carbon stock of the Indian Sundarban. This review stressed that characterizing the spatial variability of blue carbon with more sampling points, catering to the damaged trees after tropical cyclones, estuarine rejuvenation in the upper reaches, maintaining species diversity through afforestation programs, arresting coastal erosion through increasing sediment flow, and combating marine pollution have become urgent needs of the hour. The observations synthesized in this study can be helpful for academics, policy managers, and decision makers willing to uphold the sustainability of the blue carbon stock of this crucial ecosystem.

Global change scenarios in coastal river deltas and their sustainable development implications

Deltas play a critical role in the ambition to achieve global sustainable development given their relatively large shares in population and productive croplands, as well as their precarious low-lying position between upstream river basin development and rising seas. The large pressures on these systems risk undermining the persistence of delta societies, economies, and ecosystems. We analyse possible future development in 49 deltas around the globe under the Shared Socio-economic and Representative Concentration Pathways until 2100. Population density, urban fraction, and total and irrigated cropland fraction are three to twelve times greater in these deltas, on average, than in the rest of the world. Maximum river water discharges are projected to increase by 11–33 % and river sediment discharges are projected to decrease 26–37 % on average, depending on the scenario. Regional sea-level rise reaches almost 1.0 m by 2100 for certain deltas in the worst-case scenario, increasing to almost 2.0 m of relative rise considering land subsidence. Extreme sea levels could be much higher still—reaching over 4.0 m by 2100 for six of the 49 deltas analysed. Socio-economic conditions to support adaptation are the weakest among deltas with the greatest pressures, compounding the challenge of sustainable development. Asian and African deltas stand out as having heightened socio-economic challenges—huge population and land use pressures in most Asian deltas and the Nile delta; low capacity for adaptation in most African deltas and the Irrawaddy delta. Although, deltas in other parts of the world are not immune from these and other pressures, either. Because of unique pressures and processes operating in deltas, as in other “hotspots” such as small islands, mountains, and semi-arid areas, we recommend greater consideration and conceptualisation of environmental processes in global sustainable development agendas and in the Integrated Assessment Models used to guide global policy.

Mean Sea Level: The Effect of the Rise in the Environment

Mean sea level is a significant phenomenon in geodetic science and oceanography. The sea level has experienced an unprecedented rise recently, and this increase can be attributed to various human-induced activities (anthropogenic factors) ranging from deforestation to the burning of fossil fuels and population increases. Several factors cause sea level rise. It has been identified that the thermal expansion of ocean water and the melting of glaciers add to the volume of water, causing global sea level to rise, whereas phenomena such as ocean current, wind, and pressure are responsible for the regional sea level rise. This paper identifies climate change and global warming as the drivers of some factors causing sea level to rise. The effect of sea-level rise has resulted in the loss of agricultural lands, the destruction of transportation infrastructure, the loss of lands in coastal zones and migration, and the death of some aquatic animals due to saltwater intrusion. In this paper, we reviewed several pieces of literature published between 2017 and 2021 on sea-level rise and the cascading impacts of sea-level rise in various world areas. The papers reviewed borders on the mean sea level rise from different geographical areas on Earth and the monitoring of sea-level rise using different techniques. Some recommendations were also proposed for consideration.

A new deglacial climate and sea-level record from 20 to 8 ka from IODP381 site M0080, Alkyonides Gulf, eastern Mediterranean

Records of relative sea-level rise for the last deglaciation are mostly limited to coral reef records and geophysical model estimates, but observational data from regions with temperate climates is sparse. We present a new relative climatic and regional sea-level rise record for glacial Termination 1 (Marine Isotope Stages [MIS] 2–1) based on ostracode paleoecology from the upper 8 m of the International Ocean Discovery Program (IODP) Site M0080 collected on Expedition 381, in the Gulf of Alkyonides, eastern Corinth basin of the Mediterranean Sea. Results show a series of major faunal transitions from lacustrine (Ponto-Caspian, Lake Corinth) glacial-age assemblages to fully marine (Mediterranean) interglacial assemblages between 20 and 8 ka. During glacial and early deglacial intervals, the Gulf of Alkyonides was characterized by non-marine lacustrine conditions with episodic sediment input from coastal, saline lake environments. Relatively stable lake shoreline conditions marked by the distinctive Tuberoloxoconcha sp. Existed from ∼17.5 to 15 ka. During the peak deglacial interval, the BØlling-AllerØd (B-A, ∼15–13.5 ka), rapid sea-level rise is indicated by a fully marine ostracode fauna colonization, which persisted from 13.5 to 7.5 ka (Late Pleistocene-Early to Middle Holocene).The transition from lacustrine to marine environments confirms that during the last glacial maximum (LGM) low sea level (130 - 125 m below present day), the Corinth-Alkyonides depocentres were lacustrine. Marine water breached the shallow Rion and Acheloos-Cape Pappas sills, which today are ∼50–60 m deep, separating the Mediterranean and Corinth-Alkyonides system beginning about 15 ka. Based on Alkyonides sedimentation rates, mean rates of sea-level rise during the B-A flooding of the Corinth-Alkyonides system are comparable to those obtained from coral reef sea level (SL) records, at least 10–20 mm yr−1. Changes in sedimentation and sill depths in this tectonically active region may have played a role in reconnection of the Mediterranean and Corinth/Alkyonides system over a prolonged period. However, the ages and scale of the faunal changes and their clear correspondence with previously published global sea-level curves and the regional sea-level curve based on deglacial land elevation changes predicted by the ICE-7G model suggests the M0080A deglacial is dominated by the glacio-eustatic sea-level rise and records details of global climate changes during Termination 1.