Mapping Sea-Level Change in Time, Space, and Probability

Future sea-level rise generates hazards for coastal populations, economies, infrastructure, and ecosystems around the world. The projection of future sea-level rise relies on an accurate understanding of the mechanisms driving its complex spatio-temporal evolution, which must be founded on an understanding of its history. We review the current methodologies and data sources used to reconstruct the history of sea-level change over geological (Pliocene, Last Interglacial, and Holocene) and instrumental (tide-gauge and satellite alimetry) eras, and the tools used to project the future spatial and temporal evolution of sea level. We summarize the understanding of the future evolution of sea level over the near (through 2050), medium (2100), and long (post-2100) terms. Using case studies from Singapore and New Jersey, we illustrate the ways in which current methodologies and data sources can constrain future projections, and how accurate projections can motivate the development of new sea-level research questions across relevant timescales.

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Tide Gauge Records May Underestimate 20th Century Sea Level Rise

Eos ◽

10.1029/2016eo059979 ◽

2016 ◽

Vol 97 ◽

Author(s):

Leah Crane

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

20Th Century ◽

Tide Gauge ◽

Sea Level Change ◽

Tide Gauges ◽

Tide Gauge Records ◽

Level Change

Tide gauges can help measure sea level change, but their limited locations and short records make it hard to pinpoint trends. Now researchers are evaluating the instruments' limitations.

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THE VERTICAL LAND MOTION OF TIDE GAUGE AND ABSOLUTE SEA LEVEL RISE IN BOHAI SEA

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-iv-2-w5-601-2019 ◽

2019 ◽

Vol IV-2/W5 ◽

pp. 601-606

Author(s):

D. Zhou ◽

W. Sun ◽

Y. Fu ◽

X. Zhou

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Bohai Sea ◽

Tide Gauge ◽

Sea Level Change ◽

Tide Gauges ◽

Sea Level Changes ◽

The Bohai Sea ◽

Level Change ◽

Vertical Land Motion

Abstract. The ground vertical movement of the tide gauges around the Bohai sea was firstly analyzed by using the observation data from 2009 to 2017 of the nine co-located GNSS stations. It was found that the change rate of ground vertical motion of four stations was in the same order of magnitude as the sea level change. In particular, the land subsidence rate of BTGU station reaches 11.47&thinsp;mm/yr, which should be paid special attention to in the analysis of sea level change. Then combined with long-term tide gauges and the satellite altimetry results, the sea level changes in the Bohai sea and adjacent waters from 1993 to 2012 were analyzed. The relative and absolute sea level rise rates of the sea area are 3.81&thinsp;mm/yr and 3.61&thinsp;mm/yr, respectively, both are higher than the global average rate of change. At the same time, it is found that the vertical land motion of tide gauge stations is the main factor causing regional differences in relative sea level changes.

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Impacts of Future Sea-Level Rise under Global Warming Assessed from Tide Gauge Records: A Case Study of the East Coast Economic Region of Peninsular Malaysia

Land ◽

10.3390/land10121382 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1382

Author(s):

Milad Bagheri ◽

Zelina Z. Ibrahim ◽

Mohd Fadzil Akhir ◽

Bahareh Oryani ◽

Shahabaldin Rezania ◽

...

Keyword(s):

Neural Network ◽

Global Warming ◽

Sea Level Rise ◽

Sea Level ◽

East Coast ◽

Tide Gauge ◽

Sea Level Change ◽

Peninsular Malaysia ◽

Tide Gauge Records ◽

Level Change

The effects of global warming are putting the world’s coasts at risk. Coastal planners need relatively accurate projections of the rate of sea-level rise and its possible consequences, such as extreme sea-level changes, flooding, and coastal erosion. The east coast of Peninsular Malaysia is vulnerable to sea-level change. The purpose of this study is to present an Artificial Neural Network (ANN) model to analyse sea-level change based on observed data of tide gauge, rainfall, sea level pressure, sea surface temperature, and wind. A Feed-forward Neural Network (FNN) approach was used on observed data from 1991 to 2012 to simulate and predict the sea level change until 2020 from five tide gauge stations in Kuala Terengganu along the East Coast of Malaysia. From 1991 to 2020, predictions estimate that sea level would increase at a pace of roughly 4.60 mm/year on average, with a rate of 2.05 ± 7.16 mm on the East Coast of Peninsular Malaysia. This study shows that Peninsular Malaysia’s East Coast is vulnerable to sea-level rise, particularly at Kula Terengganu, Terengganu state, with a rate of 1.38 ± 7.59 mm/year, and Tanjung Gelang, Pahang state, with a rate of 1.87 ± 7.33 mm/year. As a result, strategies and planning for long-term adaptation are needed to control potential consequences. Our research provides crucial information for decision-makers seeking to protect coastal cities from the risks of rising sea levels.

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The southern North Sea as a natural palaeo-laboratory to reconstruct the coastal response to Last Interglacial sea-level rise

10.5194/egusphere-egu2020-14805 ◽

2020 ◽

Author(s):

Natasha Barlow ◽

Victor Cartelle ◽

Oliver Pollard ◽

Lauren Gregoire ◽

Natalya Gomez ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

North Sea ◽

Large Scale ◽

Recent Observation ◽

Sea Level Change ◽

Last Interglacial ◽

Large Area ◽

Level Change ◽

Southern North Sea

Current models that project sea-level rise beyond 2100 have large uncertainties because recent observation encompass a too limited range of climate variability to provide robust tests against which to simulate future changes. It is crucial to turn to the geological record where there are large-scale changes in climate, but the current interglacial provides limited evidence for how the Earth-system responds to increased temperatures, and therefore it is necessary to study previous climatically-warm periods. Global temperatures during the Last Interglacial were ~1oC warmer than pre-industrial values and 3-5oC warmer at polar latitudes, during which time global mean sea level was likely 6-9 m above present. Though the drivers of warming during the Last Interglacial are different to those of today, it is the amplified warming at polar latitudes, the primary locations of the terrestrial ice masses likely to contribute to long term sea-level rise, which makes the Last Interglacial an ideal palaeo-laboratory to understand coastal response to sea-level rise. &#160;However, our understanding of Last Interglacial sea level change is primarily limited to tropical and sub-tropical latitudes and it is important to understand the response of temperate estuarine settings to rising sea level.The ERC-funded RISeR project (Rates of Interglacial Sea-level Change, and Responses) focuses on specifically targeting palaeo shorelines buried within the southern North Sea, preserved beyond the limit of the Last Glacial Maximum ice sheets. Buried Last Interglacial sequences in this area provide a valuable record of marine transgression and are being unveiled in new geophysical and geotechnical datasets acquired to support the offshore renewable energy development. This offshore sedimentary archives offer significant advantages over the geomorphologically restricted onshore records allowing us to trace the transgression over a much large area, and should capture the earliest flooding of the Last Interglacial North Sea basin, when the far-field data suggests ice sheet melt was at it maximum. By integrating the already available datasets with newly acquired samples as part of the project, we aim to develop new palaeoenvironmental reconstructions of the Last Interglacial sea-level change from northwest Europe, providing the first chronological constraints on timing, and therefore rates. This has the potential to allow us to &#8216;fingerprint&#8217; the source of melt (Greenland and/or Antarctica) during the interglacial sea-level highstand.

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RELATIVE SEA LEVEL CHANGE ALONG THE BLACK SEA COAST FROM TIDE-GAUGE OBSERVATIONS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w8-43-2019 ◽

2019 ◽

Vol XLII-3/W8 ◽

pp. 43-47 ◽

Cited By ~ 1

Author(s):

N. B. Avsar ◽

S. H. Kutoglu

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Black Sea ◽

Tide Gauge ◽

Sea Level Change ◽

The Black Sea ◽

Relative Sea Level ◽

Level Change ◽

Black Sea Coast ◽

Gauge Station

Abstract. Potential sea level rise poses a significant threat to low-lying areas. Considering present and future of coastal areas, scientific study of sea level rise is an essential for adapting to sea level extremes. In this study, the relative sea level change in the Black Sea were investigated using data of 12 tide-gauge and 6 GNSS stations. Results generally indicated sea level rise along the Black Sea coast. Only at Bourgas tide-gauge station, a sea level fall was detected. A significant sea level change were not determined at Sinop tide-gauge station. On the other hand, at some stations such as Poti and Sile, ground subsidence contribution to relative sea level changes were observed.

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Sea Level Rise in Macau and Adjacent Southern China Coast: Historical Change and Future Projections

10.5194/egusphere-egu2020-1909 ◽

2020 ◽

Author(s):

Lin Wang ◽

Gang Huang ◽

Wen Zhou ◽

Wen Chen

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Climate Sensitivity ◽

Tide Gauge ◽

Sea Level Change ◽

Historical Change ◽

Worst Case ◽

Future Projections ◽

Level Change ◽

Emissions Scenario

&#160; &#160; Global warming-related SLR (sea level rise) constitutes a substantial threat to Macau, due to its low elevation, small size and ongoing land reclamation. This study was devised to determine the long-term variation of sea level change in Macau, as well as to develop future projections based on tide gauge and satellite data and GCM simulations, aiming to provide knowledge for SLR mitigation and adaptation.&#160; &#160; Based on local tide gauge records, sea level in Macau is now rising at an accelerated rate: 1.35 mm yr&#8722;1 over 1925&#8211;2010 and jumping to 4.2 mm yr&#8722;1 over 1970&#8211;2010, reflecting an apparent acceleration of SLR. Furthermore, the sea level near Macau rose 10% faster than the global mean during the period from 1993 to 2012. In addition, the rate of VLM (vertical land movement) at Macau is estimated at -0.153mm yr-1, contributing little to local sea level change.&#160; &#160; In the future, as projected by a suite of climate models, the rate of SLR in Macau will be about 20% higher than the global average. This is induced primarily by a greater-than-average rate of oceanic thermal expansion in Macau, together with enhanced southerly anomalies that lead to a piling up of sea water. Specifically, the sea level is projected to rise 8&#8211;12, 22&#8211;51 and 35&#8211;118 cm by 2020, 2060 and 2100 with respect to the 1986&#8211;2005 baseline climatology, respectively, depending on the emissions scenario and climate sensitivity. If we consider the medium emissions scenario RCP4.5 along with medium climate sensitivity, Macau can expect to experience an SLR of 10, 34 and 65 cm by 2020, 2060 and 2100. If the worst case happens (RCP8.5 plus high climate sensitivity), the SLR will be far higher than that in the medium case; namely, 12, 51 and 118 cm by 2020, 2060, and 2100, respectively. The SLR under the lower emissions scenario is expected to be less severe than that under the higher emissions scenarios: by 2100, an SLR of 65&#8211;118 cm in Macau under RCP8.5, almost twice as fast as that under RCP2.6. The key source of uncertainty stems from the emissions scenario and poor knowledge of climate sensitivity. By 2020, the uncertainty range is only 4 cm, yet by 2100 the range will be increased to 83 cm.

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Sea-Level Change along the Emilia-Romagna Coast from Tide Gauge and Satellite Altimetry

Remote Sensing ◽

10.3390/rs13010097 ◽

2020 ◽

Vol 13 (1) ◽

pp. 97

Author(s):

Matteo Meli ◽

Marco Olivieri ◽

Claudia Romagnoli

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Satellite Altimetry ◽

Tide Gauge ◽

Sea Level Change ◽

Global Scale ◽

Northern Adriatic Sea ◽

Northern Adriatic ◽

Level Change ◽

Grid Points

Coastal flooding and retreat are markedly enhanced by sea-level rise. Thus, it is crucial to determine the sea-level variation at the local scale to support coastal hazard assessment and related management policies. In this work we focus on sea-level change along the Emilia-Romagna coast, a highly urbanized, 130 km-long belt facing the northern Adriatic Sea, by analyzing data from three tide gauges (with data records in the last 25–10 years) and related closest grid points from CMEMS monthly gridded satellite altimetry. The results reveal that the rate of sea-level rise observed by altimetry is coherent along the coast (2.8 ± 0.5 mm/year) for the period 1993–2019 and that a negative acceleration of −0.3 ± 0.1 mm/year is present, in contrast with the global scale. Rates resulting from tide gauge time series analysis diverge from these values mainly as a consequence of a large and heterogeneous rate of subsidence in the region. Over the common timespan, altimetry and tide gauge data show very high correlation, although their comparison suffers from the short overlapping period between the two data sets. Nevertheless, their combined use allows assessment of the recent (last 25 years) sea-level change along the Emilia-Romagna coast and to discuss the role of different interacting processes in the determination of the local sea level.

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Reconciling global mean and regional sea level change in projections and observations

Nature Communications ◽

10.1038/s41467-021-21265-6 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Jinping Wang ◽

John A. Church ◽

Xuebin Zhang ◽

Xianyao Chen

Keyword(s):

Sea Level ◽

Climate Models ◽

Tide Gauge ◽

Sea Level Change ◽

Global Network ◽

Weighted Mean ◽

Level Change ◽

Regional Sea Level ◽

Global Mean ◽

Regional Sea Level Change

AbstractThe ability of climate models to simulate 20th century global mean sea level (GMSL) and regional sea-level change has been demonstrated. However, the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) sea-level projections have not been rigorously evaluated with observed GMSL and coastal sea level from a global network of tide gauges as the short overlapping period (2007–2018) and natural variability make the detection of trends and accelerations challenging. Here, we critically evaluate these projections with satellite and tide-gauge observations. The observed trends from GMSL and the regional weighted mean at tide-gauge stations confirm the projections under three Representative Concentration Pathway (RCP) scenarios within 90% confidence level during 2007–2018. The central values of the observed GMSL (1993–2018) and regional weighted mean (1970–2018) accelerations are larger than projections for RCP2.6 and lie between (or even above) those for RCP4.5 and RCP8.5 over 2007–2032, but are not yet statistically different from any scenario. While the confirmation of the projection trends gives us confidence in current understanding of near future sea-level change, it leaves open questions concerning late 21st century non-linear accelerations from ice-sheet contributions.

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Refining Estimates of Polar Ice Volumes during the MIS11 Interglacial Using Sea Level Records from South Africa

Journal of Climate ◽

10.1175/jcli-d-14-00282.1 ◽

2014 ◽

Vol 27 (23) ◽

pp. 8740-8746 ◽

Cited By ~ 8

Author(s):

Florence Chen ◽

Sarah Friedman ◽

Charles G. Gertler ◽

James Looney ◽

Nizhoni O’Connell ◽

...

Keyword(s):

South Africa ◽

Sea Level Rise ◽

Sea Level ◽

Ice Sheet ◽

Sea Level Change ◽

Polar Ice ◽

Level Change ◽

Isostatic Adjustment ◽

West Antarctic ◽

Numerical Predictions

Abstract Peak eustatic sea level (ESL), or minimum ice volume, during the protracted marine isotope stage 11 (MIS11) interglacial at ~420 ka remains a matter of contention. A recent study of high-stand markers of MIS11 age from the tectonically stable southern coast of South Africa estimated a peak ESL of 13 m. The present study refines this estimate by taking into account both the uncertainty in the correction for glacial isostatic adjustment (GIA) and the geographic variability of sea level change following polar ice sheet collapse. In regard to the latter, the authors demonstrate, using gravitationally self-consistent numerical predictions of postglacial sea level change, that rapid melting from any of the three major polar ice sheets (West Antarctic, Greenland, or East Antarctic) will lead to a local sea level rise in southern South Africa that is 15%–20% higher than the eustatic sea level rise associated with the ice sheet collapse. Taking this amplification and a range of possible GIA corrections into account and assuming that the tectonic correction applied in the earlier study is correct, the authors revise downward the estimate of peak ESL during MIS11 to 8–11.5 m.

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