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Pacific Coastal and Marine Science Center

The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls that House Department of Defense Installations

2016 News

Photograph of a portion of a crocheted art piece called Medusa.

Institute For Figuring's Crochet Coral Reef project, 2005-ongoing. Photo © the IFF.

USGS coral expert in wide-ranging panel discussion on “Understanding Coral Reefs”

Research oceanographer Curt Storlazzi (Pacific Coastal and Marine Science Center) served as a shallow-water coral expert in a panel discussion titled “Understanding Coral Reefs through Marine Science and Woolly Sculptures.” The free public event took place October 20, 2016, at the Seymour Marine Discovery Center, affiliated with the University of California, Santa Cruz (UCSC). Storlazzi was joined by deep-sea coral expert Matt McCarthy of UCSC and science communicator Margaret Wertheim. Wertheim’s projects include Crochet Coral Reef, the largest participatory art/science project in the world. The panel explored the interweaving of science and art, with a focus on coral reefs and the challenges that sea-level rise, climate change, and human-driven stressors pose to their health and sustainability. Contact: Curt Storlazzicstorlazzi@usgs.gov, 831-460-7521.

Photograph of scientist securing a wave-tide gauge on the reef flat.

USGS oceanographer Curt Storlazzi deploying an oceanographic instrument package on the reef flat off Roi-Namur Island, Kwajalein Atoll, in the Republic of the Marshall Islands (RMI).

USGS scientist briefs Department of Defense and Department of the Interior on coral reefs and climate change

On the morning of May 3, 2016, USGS oceanographer Curt Storlazzi (Pacific Coastal and Marine Science Center) briefed the Department of Defense on coral reefs and climate change in the Pacific Ocean. That afternoon, he briefed the Department of the Interior and its Office of Insular Affairs. Storlazzi leads the USGS Pacific Coral Reefs project. Recent results show that climate change may reduce the ability of coral reefs to protect tropical islands against wave attack, erosion, and salinization of drinking-water resources (read the article). Storlazzi’s briefings described these and other findings, including the likely impacts of sea-level rise and climate change on Pacific atolls that house DoD installations.

Contact: Curt Storlazzi.

2015 News

Many Atolls May be Uninhabitable Within Decades Due to Climate Change

From the USGS Newsroom, Released: 10/1/2015 4:30:00 PM

Photograph showing the impact of a large wave at the south shore of Laysan Island, with endangered Laysan teal in the foreground.

A 2012 photograph shows the impact of a large wave at the south shore of Laysan Island, with endangered Laysan teal in the foreground. Photo by Michele Reynolds. [Larger version]

A new study shows that the combined effect of storm-induced wave-driven flooding and sea level rise on island atolls may be more severe and happen sooner than previous estimates of inundation predicted by passive “bathtub” modeling for low-lying atoll islands, and especially at higher sea levels forecasted for the future due to climate change. More than half a million people live on atolls throughout the Pacific and Indian Oceans, and although the modeling was based on the Northwestern Hawaiian Islands, the results from the study apply to almost all atolls.

U.S. Geological Survey scientists and their colleagues at the Deltares Institute in the Netherlands, and the Hawaii Cooperative Studies Unit at University of Hawaii, Hilo report that numerical modeling reveals waves will synergistically interact with sea level rise, causing twice as much land forecast to be flooded for a given future sea level than currently predicted by models that do not take wave-driven water levels into account.

Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea level rise is particularly critical for low-lying coral reef-lined atoll islands; these islands have limited land and water available for human habitation, limited food sources and ecosystems that are vulnerable to inundation from sea level rise. Sea level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present.

“Many atoll islands will be flooded annually, contaminating the limited freshwater resources with saltwater, and likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought,” said USGS geologist and lead author of the study, Curt Storlazzi.

The study explored the combined effect of storm-induced wave-driven flooding and sea level rise on atoll islands within the Northwestern Hawaiian Islands, including Laysan and Midway Islands, which are home to many threatened and endangered endemic species. The same modeling approach is applicable to most populated atolls around the world.

Read this USGS news release, and learn more about the study, published in Nature's Scientific Reports.


Aerial photograph of Kwajalein Atoll showing its low-lying islands and coral reefs.

Aerial photograph of Kwajalein Atoll in the Republic of the Marshall Islands, showing its low-lying islands and coral reefs. The line of breaking waves on the left marks the reef crest, where much of the waves' energy is dissipated. Additional energy is lost through friction as the water flows shoreward over the rough surface of the healthy reef flat. USGS photograph taken May 2015 by Tom Reiss. [Larger version]

Climate Change Reduces Coral Reefs’ Ability to Protect Coasts

USGS Sound Waves Newsletter article, September 2015

Climate change may reduce the ability of coral reefs to protect tropical islands against wave attack, erosion, and salinization of the drinking-water resources that help to sustain life on those islands. A new paper by researchers from the Dutch independent institute for applied research Deltares and the USGS gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.

In order to prevent or mitigate these impacts, coastal managers need know to what extent their reef system may lose its protective function so that they can take action. The new paper, titled "The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines," gives guidance on a local reef's sensitivity to change. It was published 4 August 2015 in Geophysical Research Letters, a journal of the American Geophysical Union.

Read the entire article.


Aerial photograph of Kwajalein Atoll showing its low-lying islands and coral reefs.

Aerial photograph of Kwajalein Atoll showing its low-lying islands and coral reefs. Photograph by Curt Storlazzi. [Larger version]

Climate Change Reduces Coral Reefs’ Ability to Protect Coasts

From the USGS Newsroom, Released: 7/22/2015 1:00:00 PM

Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands. A new paper by researchers from the Dutch independent institute for applied research Deltares and the U.S. Geological Survey gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.
The article is titled, “The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines,” and is available online at doi:10.1002/2015GL064861

Read this USGS news release.

Learn more about coral reefs and climate change on our Pacific Coral Reefs Web Site.

Read more about our research on the impacts on low-lying areas of tropical Pacific islands.


Future Wave and Wind Effects on Pacific Islands—Projections Will Assist Planning for Climate Change

Excerpt from article in Sound Waves, January/February 2015 Issue (released May 5, 2015)

Aerial photograph of waves breaking on the fringing reef off Ennuebing Island, Kwajalein Atoll, Republic of the Marshall Islands.

Aerial photograph of waves breaking on the fringing reef off Ennuebing Island, Kwajalein Atoll, Republic of the Marshall Islands. From cover of “Future Wave and Wind Projections for United States and United States-Affiliated Pacific Islands.”

According to a report released in January 2015 by the U.S. Geological Survey (USGS), climate changes during the 21st century are expected to alter the highest waves and strongest winds across U.S. and U.S.-affiliated Pacific islands.

“With little to no publicly available historical wind and wave data for most of the U.S.-affiliated Pacific islands, and no future projections of waves and winds for different climate scenarios, there was a great science and management need to understand how waves and wind might change in future climates,” said Curt Storlazzi, USGS oceanographer and lead author of the study.

Scientists from the USGS and the University of California, Santa Cruz (UCSC) ran four global climate models (developed for the Intergovernmental Panel on Climate Change), using them to drive a global-wave model to look at projected changes in wave height, wave period, wave direction, wind speed, and wind direction. They focused on three Hawaiian Islands and 22 other locations on U.S.-affiliated islands in the Pacific Ocean. Modeling results project that wind and wave patterns will change over the years throughout the century, and also over certain months and seasons within each year.

Read the entire article.


Map showing the locations of the 25 modeled points within the tropical Pacific Ocean used in this study.

Map showing the locations of the 25 modeled points within the tropical Pacific Ocean used in this study. [Larger version]

Future Wave and Wind Effects on Pacific Islands

According to a new USGS report, climate changes during the 21st century are expected to alter the highest waves and strongest winds across U.S. and U.S.-affiliated islands in the Pacific Ocean. Wave and wind processes drive flooding of coastal land, potentially damaging islands’ infrastructure, fresh-water supplies, and natural resources, and harming federally protected species such as nesting seabirds. Scientists from USGS and the University of California, Santa Cruz, used computer models to look at how climate change will affect wave heights, periods, and directions, and wind speed and direction. Their detailed calculations will be useful for managers developing coastal resilience plans or ecosystem restoration efforts, and for engineers designing future infrastructure. This research was supported by the Pacific Islands Climate Change Cooperative (http://piccc.net/). USGS Open-File Report 2015-1001 is posted at http://dx.doi.org/10.3133/ofr20151001. For more information, contact Curt Storlazzi, cstorlazzi@usgs.gov, 831-460-7521.

2014 News

Photo of overwash damage on Majuro; photo by UH-SeaGrant.

Photo of overwash damage on Majuro; credit: University of Hawaii Sea Grant College Program. [Larger version]

Briefing for U.S. Ambassador in Republic of the Marshall Islands on Sea-Level Rise and Climate Change Impacts on Pacific Island Atolls

USGS research geologist Curt Storlazzi briefed Ambassador Armbruster and his staff at the U.S. Embassy on Majuro in the Republic of the Marshall Islands (RMI) on May 8–9, 2014. Storlazzi explained the project he leads, “The Impact of Sea-Level Rise and Climate Change on Department of Defense Installations on Atolls in the Pacific Ocean,” as well as other USGS efforts to understand climate-change and sea-level-rise impacts on atolls. RMI consists mainly of low-lying atolls already threatened by sea-level rise and changing climate. In March 2014, a combination of unusually high tides and waves flooded the capital for the third time in a year and led RMI’s president to declare a state of emergency. For more information, contact Curt Storlazzi, 831-460-7521, cstorlazzi@usgs.gov.

Kwajalein fieldwork: Photo of Curt Storlazzi installing wave/tide gauge mounts on the reef flat off Roi-Namur.

Fieldwork on Kwajalein Atoll: Curt Storlazzi installs wave/tide gauge mounts on the reef flat off Roi-Namur Island. [Larger version]

Continued Investigation of Sea-Level-Rise and Climate-Change Impacts on Pacific Ocean Atolls

USGS scientists from the Pacific Coastal and Marine Science Center conducted fieldwork on Kwajalein Atoll in the Republic of the Marshall Islands with collaborators from the National Oceanic and Atmospheric Administration (NOAA) April 20–May 7, 2014. Scientists from NOAA’s National Centers for Coastal Ocean Science (NCCOS) and Center for Coastal Fisheries and Habitat Research (CCFHR) joined the USGS researchers to gather data on bathymetry, topography, tides, waves, run-up, and the resulting wave-driven inundation of the atoll islands. The work is part of a project funded by the Department of Defense (DoD) to assess the impacts of sea-level rise and climate change on Pacific atolls that house DoD installations. The findings will also be useful to Pacific island nations already threatened by sea-level rise and changing climate. For more information, contact Curt Storlazzi, 831-460-7521, cstorlazzi@usgs.gov.

Photo on the island of Roi Namur showing an overwash event.

During the 2 March 2014 overwash event in the Republic of the Marshall Islands, seawater regularly topped the manmade perimeter berm on the island of Roi-Namur and covered large areas of the adjacent land surface. [Larger version]

Assessing the Vulnerability of Pacific Atolls to Climate Change

Collaboration by USGS, National Oceanic and Atmospheric Administration, and University of Hawaiʻi serendipitously captures a significant overwash event

Pacific atolls and the people who live on them are well known to be among the most vulnerable to the impacts of future climate change and sea-level rise. The USGS is leading a multiagency project to assess the impacts of sea-level rise and storm-wave inundation on small Pacific atoll islets and their freshwater resources under various sea-level rise and climatic scenarios. In March 2014, instruments deployed by the project unexpectedly recorded an event that demonstrates the work’s importance: a combination of unusually high tides and large swells that flooded many areas within the Republic of the Marshall Islands.

Read the entire article in the March/April 2014 issue of USGS Sound Waves Newsletter.

High tide at a groundwater sampling site on Roi Namur atoll, November 2013.

High tide at a groundwater sampling site at Roi-Namur Island, Kwajalein Atoll, November 2013. [Larger version]

Groundwater Studies on Kwajalein Atoll

Peter Swarzenski of the USGS Pacific Coastal and Marine Science Center continued studies of the coastal aquifer of Roi-Namur Island, Kwajalein Atoll, February 23–March 3, 2014. Swarzenski is investigating underground freshwater and saltwater using geochemical and geophysical techniques, including trace metal, nutrient, and carbon geochemistry; radon isotope analysis; piezometry; thermal conductivity; and electrical resistivity. This work is part of a joint study for the Department of Defense, Strategic Environmental Research and Development Program (SERDP) by USGS, NOAA, and the University of Hawaii, to assess impacts of sea-level rise and storm-wave inundation on infrastructure and freshwater under various sea-level rise and climate scenarios. DoD will use the findings to develop climate-change adaptation plans for infrastructure and water resources. The findings also will be useful to Pacific island nations threatened by sea-level rise and climate change. For more information contact Peter Swarzenski, 831-460-7529, pswarzen@usgs.gov.
 

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DOI: 10.5066/F7QR4V4C
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