The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls Completed
Providing basic understanding and specific information on storm-wave inundation of atoll islands that house Department of Defense installations, and assessing the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
Roi-Namur Island on Kwajalein Atoll serves as our test case
Visit the research overview web site for more information.
The Problem
Many U.S. Pacific islands are atolls fringed with coral reefs and have maximum elevations of 3–5 meters, with mean elevations of 1–2 meters. Sea level in the western Pacific Ocean has been increasing at a rate 2–3 times the global average, resulting in almost 0.3 meters of net rise since 1990. The 2012 US National Climate Assessment provided global sea level rise scenarios that ranged from 0.2 to 2.0 meters by 2100. Regional scenarios are needed. A high surf event in December 2008 overwashed numerous atolls in Micronesia, ruining freshwater supplies and destroying agriculture on approximately 60% of the inhabited islands. Sea-level rise will exacerbate the hazards posed by climate change (storms, waves, temperatures, precipitation, etc.) to infrastructure, freshwater supplies, agriculture, and habitats for threatened and endangered species on U.S. and U.S.-affiliated atoll islands.
Project Objectives
- Provide basic understanding and specific information on storm-wave-induced overwash and inundation of atoll islands that house Department of Defense (DoD) installations.
- Assess the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
- Use Roi-Namur Island (Reagan Test Site–U.S. Army Kwajalein Atoll) on Kwajalein Atoll in the Republic of the Marshall Islands (U.S. Associated Pacific Islands) as a test case based on historical information, sea-level rise predictions, and global climate model (GCM) output.
Below are other science projects associated with this project.
Coastal Climate Impacts
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Below are publications associated with this project.
Tropical cyclone projections: Changing climate threats for Pacific Island defense installations
Spatial variability of sediment transport processes over intratidal and subtidal timescales within a fringing coral reef system
Mechanisms of wave‐driven water level variability on reef‐fringed coastlines
Most atolls will be uninhabitable by the mid-21st century because of sea-level rise exacerbating wave-driven flooding
Challenges of forecasting flooding on coral reef–lined coasts
A Bayesian-based system to assess wave-driven flooding hazards on coral reef-lined coasts
Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands
Atoll groundwater movement and its response to climatic and sea-level fluctuations
Wave dynamics and flooding on low-lying tropical reef-lined coasts
Doubling of coastal flooding frequency within decades due to sea-level rise
Land-use change and managed aquifer recharge effects on the hydrogeochemistry of two contrasting atoll island aquifers, Roi-Namur Island, Republic of the Marshall Islands
Identification and classification of very low frequency waves on a coral reef flat
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- Overview
Providing basic understanding and specific information on storm-wave inundation of atoll islands that house Department of Defense installations, and assessing the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
Roi-Namur Island on Kwajalein Atoll serves as our test case
Visit the research overview web site for more information.
The Problem
Many U.S. Pacific islands are atolls fringed with coral reefs and have maximum elevations of 3–5 meters, with mean elevations of 1–2 meters. Sea level in the western Pacific Ocean has been increasing at a rate 2–3 times the global average, resulting in almost 0.3 meters of net rise since 1990. The 2012 US National Climate Assessment provided global sea level rise scenarios that ranged from 0.2 to 2.0 meters by 2100. Regional scenarios are needed. A high surf event in December 2008 overwashed numerous atolls in Micronesia, ruining freshwater supplies and destroying agriculture on approximately 60% of the inhabited islands. Sea-level rise will exacerbate the hazards posed by climate change (storms, waves, temperatures, precipitation, etc.) to infrastructure, freshwater supplies, agriculture, and habitats for threatened and endangered species on U.S. and U.S.-affiliated atoll islands.
Project Objectives
- Provide basic understanding and specific information on storm-wave-induced overwash and inundation of atoll islands that house Department of Defense (DoD) installations.
- Assess the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
- Use Roi-Namur Island (Reagan Test Site–U.S. Army Kwajalein Atoll) on Kwajalein Atoll in the Republic of the Marshall Islands (U.S. Associated Pacific Islands) as a test case based on historical information, sea-level rise predictions, and global climate model (GCM) output.
- Science
Below are other science projects associated with this project.
Coastal Climate Impacts
The impacts of climate change and sea-level rise around the Pacific and Arctic Oceans can vary tremendously. Thus far the vast majority of national and international impact assessments and models of coastal climate change have focused on low-relief coastlines that are not near seismically active zones. Furthermore, the degree to which extreme waves and wind will add further stress to coastal... - Data
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- Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with this project.
Filter Total Items: 32Tropical cyclone projections: Changing climate threats for Pacific Island defense installations
Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by their frequency and intensity, near islands housing major U.S. defense installations was the primaryAuthorsMatthew J. Widlansky, Hariharasubramanian Annamalai, Stephen B. Gingerich, Curt D. Storlazzi, John J. Marra, Kevin I. Hodges, Barry Choy, Akio KitohSpatial variability of sediment transport processes over intratidal and subtidal timescales within a fringing coral reef system
Sediment produced on fringing coral reefs that is transported along the bed or in suspension affects ecological reef communities as well as the morphological development of the reef, lagoon, and adjacent shoreline. This study quantified the physical process contribution and relative importance of sea‐swell waves, infragravity waves, and mean currents to the spatial and temporal variability of sediAuthorsAndrew Pomeroy, Ryan J. Lowe, Marco Ghisalberti, Gundula Winter, Curt D. Storlazzi, Michael V. W. CuttlerMechanisms of wave‐driven water level variability on reef‐fringed coastlines
Wave‐driven water level variability (and runup at the shoreline) is a significant cause of coastal flooding induced by storms. Wave runup is challenging to predict, particularly along tropical coral reef‐fringed coastlines due to the steep bathymetric profiles and large bottom roughness generated by reef organisms, which can violate assumptions in conventional models applied to open sandy coastlinAuthorsMark L. Buckley, Ryan J. Lowe, Jeff E. Hansen, Ap R. van Dongeren, Curt D. StorlazziMost atolls will be uninhabitable by the mid-21st century because of sea-level rise exacerbating wave-driven flooding
Sea levels are rising, with the highest rates in the tropics, where thousands of low-lying coral atoll islands are located. Most studies on the resilience of these islands to sea-level rise have projected that they will experience minimal inundation impacts until at least the end of the 21st century. However, these have not taken into account the additional hazard of wave-driven overwash or its imAuthorsCurt D. Storlazzi, Stephen B. Gingerich, Ap van Dongeren, Olivia Cheriton, Peter W. Swarzenski, Ellen Quataert, Clifford I. Voss, Donald W. Field, Hariharasubramanian Annamalai, Greg A. Piniak, Robert T. McCallChallenges of forecasting flooding on coral reef–lined coasts
Understanding wave-driven coastal flooding is a challenging scientific problem; the need for forecasts is becoming more urgent because of sea level rise, climate change, and ever-growing coastal populations. The tools developed for sandy shorelines are generally not applicable to coral reef–lined coasts with their complex bathymetry, hydrodynamically rough reef platforms, steep and poorly sorted bAuthorsCurt D. StorlazziA Bayesian-based system to assess wave-driven flooding hazards on coral reef-lined coasts
Many low-elevation, coral reef-lined, tropical coasts are vulnerable to the effects of climate change, sea level rise, and wave-induced flooding. The considerable morphological diversity of these coasts and the variability of the hydrodynamic forcing that they are exposed to make predicting wave-induced flooding a challenge. A process-based wave-resolving hydrodynamic model (XBeach Non-HydrostaticAuthorsS. G. Pearson, Curt D. Storlazzi, A. R. van Dongeren, M. F. S. Tissier, A. J. H. M. ReniersProjected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands
Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to clAuthorsJames B. Shope, Curt D. Storlazzi, Ron HoekeAtoll groundwater movement and its response to climatic and sea-level fluctuations
Groundwater resources of low-lying atoll islands are threatened due to short-term and long-term changes in rainfall, wave climate, and sea level. A better understanding of how these forcings affect the limited groundwater resources was explored on Roi-Namur in the Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-overwash event occurred and the island’s aquifeAuthorsFerdinand K. J. Oberle, Peter W. Swarzenski, Curt D. StorlazziWave dynamics and flooding on low-lying tropical reef-lined coasts
Many tropical islands and coasts are lined with coral reefs. These reefs are host to valuable ecosystems that support abundant marine species and provide resources for fisheries and recreation. As a flood defense, reefs protect coastlines from coastal storm damage and flooding by reducing the majority of incident wave energy. However, during storm and large swell conditions, coastal wave-driven flAuthorsAp van Dongeran, Curt D. Storlazzi, Ellen Quataert, Stuart PearsonDoubling of coastal flooding frequency within decades due to sea-level rise
Global climate change drives sea-level rise, increasing the frequency of coastal flooding. In most coastal regions, the amount of sea-level rise occurring over years to decades is significantly smaller than normal ocean-level fluctuations caused by tides, waves, and storm surge. However, even gradual sea-level rise can rapidly increase the frequency and severity of coastal flooding. So far, globalAuthorsSean Vitousek, Patrick L. Barnard, Charles H. Fletcher, Neil Frazer, Li H. Erikson, Curt D. StorlazziLand-use change and managed aquifer recharge effects on the hydrogeochemistry of two contrasting atoll island aquifers, Roi-Namur Island, Republic of the Marshall Islands
Freshwater resources on low-lying atoll islands are highly vulnerable to climate change and sea-level rise. In addition to rainwater catchment, groundwater in the freshwater lens is a critically important water resource on many atoll islands, especially during drought. Although many atolls have high annual rainfall rates, dense natural vegetation and high evapotranspiration rates can limit recharAuthorsMehrdad Hejazian, Jason J. Gurdak, Peter W. Swarzenski, Kingsley Odigie, Curt D. StorlazziIdentification and classification of very low frequency waves on a coral reef flat
Very low frequency (VLF, 0.001–0.005 Hz) waves are important drivers of flooding of low-lying coral reef-islands. In particular, VLF wave resonance is known to drive large wave runup and subsequent overwash. Using a 5 month data set of water levels and waves collected along a cross-reef transect on Roi-Namur Island in the Republic of the Marshall Islands, the observed VLF motions were categorizedAuthorsMatthijs Gawehn, Ap van Dongeran, Arnold van Rooijen, Curt D. Storlazzi, Olivia Cheriton, Ad Reniers - News
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