Quantifying processes contributing to marine hazards  to inform coastal climate resilience assessments,  demonstrated for the Caribbean Sea

Abstract. Scientific evidence is critical to underpin the decisions associated with shoreline management, to build climate resilient communities and infrastructure. We explore the role of waves, storm surges and sea level rise for the Caribbean region with a focus on coastal impacts in the eastern Caribbean islands. We simulate past extreme events and a worst-case scenario, modelling the storm surges and waves, suggesting a storm surge might reach 1.5 m, depending on the underwater topography. Coastal wave heights up to 12 m offshore and up to 5 m near the coast of St Vincent are simulated with a regional wave model. We deliver probabilistic sea level projections for 2100, with a low probability/high impact estimate of possible sea level rise up to 2.2 m, exceeding the 1.8 m global estimate for the same scenario. We introduce a Combined Vulnerability Index, which allows a quantitative assessment of relative risk across the region, showing that sea level rise is the most important risk factor everywhere, but wave impacts are important on windward coasts, increasing to the north, towards the main hurricane track. Our work provides quantitative evidence for policy makers, scientists, and local communities to actively prepare for and protect against climate change.

Download Full-text

Changing impacts of Alaska-Aleutian subduction zone tsunamis in California under future sea-level rise

Nature Communications ◽

10.1038/s41467-021-27445-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Tina Dura ◽

Andra J. Garner ◽

Robert Weiss ◽

Robert E. Kopp ◽

Simon E. Engelhart ◽

...

Keyword(s):

Los Angeles ◽

Sea Level Rise ◽

Subduction Zone ◽

Sea Level ◽

Source Region ◽

Coastal Hazards ◽

Long Beach ◽

Distant Source ◽

Case Scenario ◽

Worst Case

AbstractThe amplification of coastal hazards such as distant-source tsunamis under future relative sea-level rise (RSLR) is poorly constrained. In southern California, the Alaska-Aleutian subduction zone has been identified as an earthquake source region of particular concern for a worst-case scenario distant-source tsunami. Here, we explore how RSLR over the next century will influence future maximum nearshore tsunami heights (MNTH) at the Ports of Los Angeles and Long Beach. Earthquake and tsunami modeling combined with local probabilistic RSLR projections show the increased potential for more frequent, relatively low magnitude earthquakes to produce distant-source tsunamis that exceed historically observed MNTH. By 2100, under RSLR projections for a high-emissions representative concentration pathway (RCP8.5), the earthquake magnitude required to produce >1 m MNTH falls from ~Mw9.1 (required today) to Mw8.0, a magnitude that is ~6.7 times more frequent along the Alaska-Aleutian subduction zone.

Download Full-text

Developing future sea level services for Small Island Developing States

10.5194/egusphere-egu2020-6495 ◽

2020 ◽

Author(s):

Svetlana Jevrejeva ◽

Judith Wolf ◽

Andy Matthews ◽

Joanne Williams ◽

David Byrne ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Water Level ◽

Sea Level ◽

Future Climate Change ◽

Small Island ◽

Caribbean Region ◽

Caribbean Islands ◽

The Caribbean ◽

And Sea Level

The Caribbean islands encompass some of the most vulnerable coastlines in terms of sea level rise, exposure to tropical cyclones, changes in waves and storm surges. Climate in the Caribbean is already changing and sea level rise impacts are already being felt. Considerable local and regional variations in the rate, magnitude, and direction of sea-level change can be expected as a result of thermal expansion, tectonic movements, and changes in ocean circulation. Governments in the Caribbean recognise that climate change and sea level rise are serious threats to the sustainable development and economic growth of the Caribbean islands and urgent actions are required to increase the resilience and make decisions about how to adapt to future climate change (Caribbean Marine Climate Change Report Card 2017; IPCC 2014).As part of the UK Commonwealth Marine Economies (CME) Programme and through collaboration with local stakeholders in St Vincent, we have identified particular areas at risk from changing water level and wave conditions. The Caribbean Sea, particularly the Lesser Antilles, suffers from limited observational data due to a lack of coastal monitoring, making numerical models even more important to fill this gap. The current projects brings together improved access to tide gauge observations, as well as global, regional and local water level and wave modelling to provide useful tools for coastal planners.We present our initial design of a coastal data hub with sea level information for stakeholder access in St. Vincent and Grenadines, Grenada and St Lucia, with potential development of the hub for the Caribbean region. The work presented here is a contribution to the wide range of ongoing activities under the Commonwealth Marine Economies (CME) Programme in the Caribbean, falling within the work package &#8220;Development of a coastal data hub for stakeholder access in the Caribbean region&#8221;, under the NOC led projects &#8220;Climate Change Impact Assessment: Ocean Modelling and Monitoring for the Caribbean CME states&#8221;.

Download Full-text

IMPACT OF SEA LEVEL RISE ON THE ACCESSIBILITY OF COASTAL PORTS: A CASE STUDY OF THE PORT OF ZEEBRUGGE (BELGIUM)

Coastal Engineering Proceedings ◽

10.9753/icce.v36.risk.107 ◽

2018 ◽

pp. 107

Author(s):

Gerasimos A. Kolokythas ◽

Bart De Maerschalck ◽

Joris Vanlede ◽

Kai Chu

Keyword(s):

Numerical Simulations ◽

Sea Level Rise ◽

Sea Level ◽

Coastal Zone ◽

Current Situation ◽

Reference Scenario ◽

Case Scenario ◽

Worst Case ◽

Access Channel

The effect of sea level rise on the hydrodynamic flow in the Belgian coastal zone is investigated in the light of the nautical accessibility of the port of Zeebrugge in Belgium. To this end, numerical simulations are performed considering three different scenarios of sea level rise along with a reference scenario (current situation). Specifically, a moderate, a warm and a worst case scenario of sea level rise (SLR) equal to 60 cm, 90 cm and 200 cm by the year 2100, are considered. The main objective is to find out how the strong tidal currents, which are mainly directed transversely to the access channel and limit the access to the port to a certain tidal window, will be affected by the considered SLR scenarios.

Download Full-text

In the Wake of Change: An Urban Design Response to Rising Sea Levels in Wellington City

10.26686/wgtn.16985008.v1 ◽

2021 ◽

Author(s):

◽

Emily Oakley

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Urban Design ◽

Sea Level Change ◽

City Council ◽

Case Scenario ◽

Worst Case ◽

Level Change ◽

Sea Wall ◽

The City

This thesis focuses on possible urban design responses to a worst-case scenario for sea level change: a rise of one metre by the year 2100. Wellington City is comparable to many coastal cities around the world; much of the city sits on lowlying reclaimed land. A rise in sea level of one metre could result in extensive damage to buildings and infrastructure. Scientists predict that seas will rise somewhere between 0.18m and 1.2m by the end of the century. New Zealand’s Ministry for the Environment advises local bodies to plan for a rise in sea level of at least 0.8m by the year 2090. Wellington City Council has begun to research the possible effects of sea level rise on the city but has not yet seriously considered design options in response to this. The uncertainties regarding the extent of sea level rise mean its impact on Wellington City could be minimal (0.5 m rise) or extensive (1.5m rise). Dykes, sea walls and levees have been constructed for centuries to protect local populations. These can be detrimental to urban quality, and can impede the connections between cities and their waterfronts. Up until now, their effects on overall urban design have rarely been considered. Urban designs adopted internationally for flood defence were reviewed with regard to Wellington City’s needs. A mapping study of three possible scenarios (0.5m, 1.0m, 1.5m) for sea level change in Wellington City has been made, including assessment with respect to urban design principles. This thesis concludes by offering a realistic response to the one metre scenario. Three sections of the city are developed further to demonstrate how a unified response could be developed throughout the city. The chosen response to the problem of sea level rise in Wellington City seeks to preserve sense of place while introducing new urban design concepts. The chosen design uses a sea wall to protect the existing city against a one-metre rise in sea level, and creates an amphibious zone on its seaward side. The sea wall sits inside the city rather than around it. As well as forming a boundary, it is a public structure offering visual connections between city and sea, and maintaining the essential character of the waterfront. The amphibious zone is designed to withstand flooding during storms and high sea surges. Design in this zone includes new building processes that adapt with sea level changes.

Download Full-text

In the Wake of Change: An Urban Design Response to Rising Sea Levels in Wellington City

10.26686/wgtn.16985008 ◽

2021 ◽

Author(s):

◽

Emily Oakley

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Urban Design ◽

Sea Level Change ◽

City Council ◽

Case Scenario ◽

Worst Case ◽

Level Change ◽

Sea Wall ◽

The City

This thesis focuses on possible urban design responses to a worst-case scenario for sea level change: a rise of one metre by the year 2100. Wellington City is comparable to many coastal cities around the world; much of the city sits on lowlying reclaimed land. A rise in sea level of one metre could result in extensive damage to buildings and infrastructure. Scientists predict that seas will rise somewhere between 0.18m and 1.2m by the end of the century. New Zealand’s Ministry for the Environment advises local bodies to plan for a rise in sea level of at least 0.8m by the year 2090. Wellington City Council has begun to research the possible effects of sea level rise on the city but has not yet seriously considered design options in response to this. The uncertainties regarding the extent of sea level rise mean its impact on Wellington City could be minimal (0.5 m rise) or extensive (1.5m rise). Dykes, sea walls and levees have been constructed for centuries to protect local populations. These can be detrimental to urban quality, and can impede the connections between cities and their waterfronts. Up until now, their effects on overall urban design have rarely been considered. Urban designs adopted internationally for flood defence were reviewed with regard to Wellington City’s needs. A mapping study of three possible scenarios (0.5m, 1.0m, 1.5m) for sea level change in Wellington City has been made, including assessment with respect to urban design principles. This thesis concludes by offering a realistic response to the one metre scenario. Three sections of the city are developed further to demonstrate how a unified response could be developed throughout the city. The chosen response to the problem of sea level rise in Wellington City seeks to preserve sense of place while introducing new urban design concepts. The chosen design uses a sea wall to protect the existing city against a one-metre rise in sea level, and creates an amphibious zone on its seaward side. The sea wall sits inside the city rather than around it. As well as forming a boundary, it is a public structure offering visual connections between city and sea, and maintaining the essential character of the waterfront. The amphibious zone is designed to withstand flooding during storms and high sea surges. Design in this zone includes new building processes that adapt with sea level changes.

Download Full-text

Centennial response of Greenland’s three largest outlet glaciers

Nature Communications ◽

10.1038/s41467-020-19580-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Shfaqat A. Khan ◽

Anders A. Bjørk ◽

Jonathan L. Bamber ◽

Mathieu Morlighem ◽

Michael Bevis ◽

...

Keyword(s):

Mass Loss ◽

Sea Level Rise ◽

Sea Level ◽

Greenland Ice Sheet ◽

External Forcing ◽

Case Scenario ◽

Worst Case ◽

Worst Case Scenario ◽

Historical Photographs

AbstractThe Greenland Ice Sheet is the largest land ice contributor to sea level rise. This will continue in the future but at an uncertain rate and observational estimates are limited to the last few decades. Understanding the long-term glacier response to external forcing is key to improving projections. Here we use historical photographs to calculate ice loss from 1880–2012 for Jakobshavn, Helheim, and Kangerlussuaq glacier. We estimate ice loss corresponding to a sea level rise of 8.1 ± 1.1 millimetres from these three glaciers. Projections of mass loss for these glaciers, using the worst-case scenario, Representative Concentration Pathways 8.5, suggest a sea level contribution of 9.1–14.9 mm by 2100. RCP8.5 implies an additional global temperature increase of 3.7 °C by 2100, approximately four times larger than that which has taken place since 1880. We infer that projections forced by RCP8.5 underestimate glacier mass loss which could exceed this worst-case scenario.

Download Full-text

Worst case scenario as stakeholder decision support: a 5- to 6-m sea level rise in the Rhone delta, France

Climatic Change ◽

10.1007/s10584-008-9446-5 ◽

2008 ◽

Vol 91 (1-2) ◽

pp. 123-143 ◽

Cited By ~ 19

Author(s):

Marc Poumadère ◽

Claire Mays ◽

Gabriela Pfeifle ◽

Athanasios T. Vafeidis

Keyword(s):

Decision Support ◽

Sea Level Rise ◽

Sea Level ◽

Case Scenario ◽

Worst Case ◽

Worst Case Scenario ◽

Rhône Delta ◽

Rhone Delta

Download Full-text

Potential Impacts of Storm Surges and Sea-level Rise on Nesting Habitat of Red-breasted Mergansers (Mergus serrator) on Barrier Islands in New Brunswick, Canada

Waterbirds ◽

10.1675/063.038.0110 ◽

2015 ◽

Vol 38 (1) ◽

pp. 77-85 ◽

Cited By ~ 1

Author(s):

Shawn R. Craik ◽

Alan R. Hanson ◽

Rodger D. Titman ◽

Matthew L. Mahoney ◽

Éric Tremblay

Keyword(s):

New Brunswick ◽

Sea Level Rise ◽

Sea Level ◽

Storm Surges ◽

Barrier Islands ◽

Nesting Habitat ◽

Mergus Serrator ◽

And Sea Level

Download Full-text

Impact of climate change on New York City’s coastal flood hazard: Increasing flood heights from the preindustrial to 2300 CE

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1703568114 ◽

2017 ◽

Vol 114 (45) ◽

pp. 11861-11866 ◽

Cited By ~ 73

Author(s):

Andra J. Garner ◽

Michael E. Mann ◽

Kerry A. Emanuel ◽

Robert E. Kopp ◽

Ning Lin ◽

...

Keyword(s):

New York ◽

New York City ◽

Sea Level Rise ◽

Sea Level ◽

Tropical Cyclones ◽

York City ◽

Flood Hazard ◽

Storm Surges ◽

Cmip5 Models ◽

Tidal Level

The flood hazard in New York City depends on both storm surges and rising sea levels. We combine modeled storm surges with probabilistic sea-level rise projections to assess future coastal inundation in New York City from the preindustrial era through 2300 CE. The storm surges are derived from large sets of synthetic tropical cyclones, downscaled from RCP8.5 simulations from three CMIP5 models. The sea-level rise projections account for potential partial collapse of the Antarctic ice sheet in assessing future coastal inundation. CMIP5 models indicate that there will be minimal change in storm-surge heights from 2010 to 2100 or 2300, because the predicted strengthening of the strongest storms will be compensated by storm tracks moving offshore at the latitude of New York City. However, projected sea-level rise causes overall flood heights associated with tropical cyclones in New York City in coming centuries to increase greatly compared with preindustrial or modern flood heights. For the various sea-level rise scenarios we consider, the 1-in-500-y flood event increases from 3.4 m above mean tidal level during 1970–2005 to 4.0–5.1 m above mean tidal level by 2080–2100 and ranges from 5.0–15.4 m above mean tidal level by 2280–2300. Further, we find that the return period of a 2.25-m flood has decreased from ∼500 y before 1800 to ∼25 y during 1970–2005 and further decreases to ∼5 y by 2030–2045 in 95% of our simulations. The 2.25-m flood height is permanently exceeded by 2280–2300 for scenarios that include Antarctica’s potential partial collapse.

Download Full-text