My interests span the coastal zone, from seacliff erosional processes to sediment dynamics in the shallow coastal ocean. My research focuses on the quantitative study of hydrodynamics, sediment transport, and geomorphology in coastal and marine environments.
Research Topics
Coral reef morphology, hydrodynamics, and sediment, nutrient, contaminant, and larval transport
The role of coral reefs and other coastal ecosystems in coastal hazard risk reduction
The interplay between geologic structure, climatic fluctuations, and coastal processes
High-resolution oceanographic instrumentation and coastal mapping techniques
The influence of physical processes on coral reef ecosystems
Many tropical coastal environments have been impacted by infrastructure development, nutrient and contaminant delivery, and natural and human-induced sedimentation. The high geomorphic and hydrodynamic complexity both within and between coral reefs, in conjunction with past technical restrictions, has limited our understanding of the nature of flow and the resulting flux of physical, chemical, and biologic material in these ecosystems. Understanding the physical controls on the timing and magnitude of flow and sediment, larvae, nutrient, and contaminant transport, along with their impact on seafloor geomorphology, stability, and sedimentation in these refugia are essential to assessing modern anthropogenic impacts (climate change, etc.) on these ecosystems and help guide how restoration can increase the resiliency of coral reef-lined coastal communities.
See: Coral Reef Project and The Value of U.S. Coral Reefs for Risk Reduction (links below)
The influence of climate change and sea-level rise on coral reef-lined coasts
Observations show that sea level is rising and recent projections indicate sea level will exceed 1.0 m, and may reach 2.0 m, above 2000 levels by the end of the 21st century. The amount of land and water available for human habitation, water and food sources, and ecosystems along coral reef-lined coasts is limited and vulnerable to wave-driven flooding during storms. Rising sea levels will further exacerbate the impacts of storms on coral reef-lined coasts by reducing wave breaking (and thus energy dissipation) over reefs and result in greater wave energy impacting the shoreline, causing increased flooding and changes to the coast such as erosion. Understanding the physical controls on the timing and magnitude of flooding, along with their impact on coastal geomorphology, are essential to assessing impacts on, and the future sustainability of, coastal infrastructure, agriculture, freshwater availability, and ecosystems.
See: Low-lying areas of tropical Pacific islands (links below)
Professional Experience
2002-present: Research Geologist and Oceanographer, USGS Coastal and Marine Hazards and Resources Program
2002-present: Research Associate, University of California at Santa Cruz (UCSC) Institute for Marine Sciences
Education and Certifications
2002-2004: Research Fellow, Partnership for Interdisciplinary Studies of Coastal Oceans Consortium
2000-2002: Post-doctoral Researcher, UCSC Institute for Marine Sciences
2000: Ph.D., UCSC, Earth Sciences Department
1996: B.Sc., University of Delaware, Geology Department
Science and Products
Coral Reef Project
Coastal Climate Impacts
Reef Hydrodynamics and Sediment Processes
Reef Resource Assessments - Planning for the Future
Low-lying areas of tropical Pacific islands
Role of Reefs in Coastal Protection
The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
Coral Reef Project: Kwajalein Island
Coral Reef Project: Roi-Namur Island
Coral Reef Project: Molokaʻi
Coral Reef Project: Maui
Using Video Imagery to Study Wave Dynamics: Tres Palmas
Hydrographic and sediment field data collected in the vicinity of Wainwright, Alaska, in 2009
Pharmaceuticals and personal care products measured in passive samplers at seven coastal sites off West Maui during February and March 2017
National Assessment of Hurricane-Induced Coastal Erosion Hazards: Puerto Rico
Ocean wave time-series data simulated with a global-scale numerical wave model under the influence of projected CMIP6 wind and sea ice fields
Model parameter input files to compare the influence of channels in fringing coral reefs on alongshore variations in wave-driven runup along the shoreline
Aerial imagery and structure-from-motion-derived shallow water bathymetry from a UAS survey of the coral reef off Waiakane, Molokai, Hawaii, June 2018
Flooding extent polygons for modelled wave-driven water levels in Florida with and without projected coral reef degradation
Projected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods for the State of Florida and the Commonwealth of Puerto Rico before and after Hurricanes Irma and Maria due to the storms' damage to the coral reefs
Projected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods for the State of Florida, the Commonwealth of Puerto Rico, and the Territory of the U.S. Virgin Islands for current and potentially restored coral reefs
Near-shore seawater-column measurements of excess radon (Rn-222) and water levels, Faga'alu Bay, Tutuila, American Samoa, August 2018
Modeled extreme total water levels along the U.S. west coast
Model parameter input files to compare locations of coral reef restoration on different reef profiles to reduce coastal flooding
Views of the Sea Floor in Northern Monterey Bay, California
Physicochemical coastal groundwater dynamics between Kauhakō Crater lake and Kalaupapa settlement, Moloka‘i, Hawai‘i
Wave-driven hydrodynamic processes over fringing reefs with varying slopes, depths, and roughness: Implications for coastal protection
Pharmaceuticals and personal care products in passive samplers at seven coastal sites off West Maui, Hawaiʻi:
A numerical study of geomorphic and oceanographic controls on wave-driven runup on fringing reefs with shore-normal channels
Characterizing storm-induced coastal change hazards along the United States West Coast
High-resolution observations of submarine groundwater discharge reveal the fine spatial and temporal scales of nutrient exposure on a coral reef: Faga'alu, AS
Human and ecosystem health in coastal systems
Action plan for restoration of coral reef coastal protection services: Case study example and workbook
Biology: Integrating core to essential variables (Bio-ICE) task team teport for hard corals
Rigorously valuing the coastal hazard risks reduction provided by potential coral reef restoration in Florida and Puerto Rico
Rigorously valuing the impact of projected coral reef degradation on coastal hazard risk in Florida
Rigorously valuing the impact of Hurricanes Irma and Maria on coastal hazard risks in Florida and Puerto Rico
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
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Coral Reef Project
Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.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...Reef Hydrodynamics and Sediment Processes
As part of the USGS Coral Reef Project, the overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.Reef Resource Assessments - Planning for the Future
We are mapping and assessing all of the important geologic and oceanographic factors to identify those coral reefs most at risk and those reefs that are potentially the most resilient and the most likely to recover from natural and human-driven impacts.Low-lying areas of tropical Pacific islands
Sea level is rising faster than projected in the western Pacific, so understanding how wave-driven coastal flooding will affect inhabited, low-lying islands—most notably, the familiar ring-shaped atolls—as well as the low-elevation areas of high islands in the Pacific Ocean, is critical for decision-makers in protecting infrastructure or relocating resources and people.Role of Reefs in Coastal Protection
We are combining ocean, engineering, ecologic, social, and economic modeling to provide a high-resolution, rigorous, spatially-explicit valuation of the coastal flood protection benefits provided by coral reefs and the cost effectiveness of reef restoration for enhancing those benefits.The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
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.Coral Reef Project: Kwajalein Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.Coral Reef Project: Roi-Namur Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.Coral Reef Project: Molokaʻi
As part of the USGS Coral Reef Project, recent USGS work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.Coral Reef Project: Maui
As part of USGS Coral Reef Project studies, the USGS has been heavily involved in efforts to improve the health and resilience of Maui's coral reef system, bringing expertise in mapping, circulation and sediment studies, and seismic surveys.Using Video Imagery to Study Wave Dynamics: Tres Palmas
To study wave dynamics along an active coastline, video cameras were installed on the west coast of Puerto Rico at Tres Palmas in Rincón. - Data
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Hydrographic and sediment field data collected in the vicinity of Wainwright, Alaska, in 2009
This dataset consists of hydrographic, geomorphic, and sediment field measurements obtained during the ice-free summer of 2009 in the vicinity of Wainwright, Alaska. Time-series data were collected with a bottom-mounted instrument package and consist of wave statistics, vertical water flow velocity profiles, water temperatures, conductivity, and salinity concentrations. Data collected at distinctPharmaceuticals and personal care products measured in passive samplers at seven coastal sites off West Maui during February and March 2017
Passive membrane samplers—semipermeable membrane devices and polar organic chemical integrative samplers—were deployed for 22 continuous days at 7 sites along the West Maui, Hawai'i, coastline in February and March 2017 to assess organic contaminants at shallow coral reef ecosystems from diverse upstream inputs.National Assessment of Hurricane-Induced Coastal Erosion Hazards: Puerto Rico
These datasets contain information on the probabilities of hurricane-induced erosion (collision, inundation, and overwash) for each 100-meter (m) section of the Puerto Rico open-ocean coastline for category 1-5 hurricanes. The analysis is based on a storm-impact scaling model (Sallenger, 2000; https://www.jstor.org/stable/4300099) that uses observations of beach morphology combined with sophisticaOcean wave time-series data simulated with a global-scale numerical wave model under the influence of projected CMIP6 wind and sea ice fields
This dataset contains projected hourly time-series data of waves at distinct points along all open U.S. coasts for years 2020-2050. The 'projections' (estimates of long-term future conditions) were developed by running the National Oceanic and Atmospheric Administration's (NOAA) WAVEWATCHIII wave model forced with winds and sea ice cover from seven separate high-resolution Global Climate / GeneralModel parameter input files to compare the influence of channels in fringing coral reefs on alongshore variations in wave-driven runup along the shoreline
An extensive set of physics-based XBeach Non-hydrostatic hydrodynamic model simulations (with input files here included) were used to evaluate the influence of shore-normal reef channels on flooding along fringing reef-lined coasts, specifically during extreme wave conditions when the risk for coastal flooding and the resulting impact to coastal communities is greatest. These input files accompanyAerial imagery and structure-from-motion-derived shallow water bathymetry from a UAS survey of the coral reef off Waiakane, Molokai, Hawaii, June 2018
An unoccupied aerial system (UAS) was used to acquire high-resolution imagery of the shallow fringing coral reef at Waiakane, Molokai, Hawaii, on 24 June 2018. Imagery was acquired over an area between the shoreline and approximately 900 meters offshore, covering approximately 16 hectares. The imagery was processed using structure-from-motion (SfM) photogrammetric techniques with additional refracFlooding extent polygons for modelled wave-driven water levels in Florida with and without projected coral reef degradation
This data release presents projected flooding extent polygon (flood masks) shapefiles based on wave-driven total water levels for the State Florida (the Florida Peninsula and the Florida Keys). There are 12 associated flood mask shapefiles: one for each of four nearshore wave energy return periods (rp; 10-, 50-, 100-, and 500-years), the current scenario (base) and each of the degradation scenarioProjected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods for the State of Florida and the Commonwealth of Puerto Rico before and after Hurricanes Irma and Maria due to the storms' damage to the coral reefs
This data release provides flooding extent polygons based on wave-driven total water levels for the coral lined coast of Florida and the Commonwealth of Puerto Rico. The wave and sea-level conditions were then propagated using the XBeach over 100-m spaced shore-normal transects modified to account for base and post-storm scenarios. In situ observations following hurricanes Irma and Maria were usedProjected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods for the State of Florida, the Commonwealth of Puerto Rico, and the Territory of the U.S. Virgin Islands for current and potentially restored coral reefs
This data release provides flooding extent polygons based on wave-driven total water levels for the coral lined coasts of Florida, Puerto Rico, and the U.S. Virgin Islands. The locations of the restoration lines along and across shore were defined by the presence of continuous coral/hardbottom habitat of greater than 100 m alongshore length and proximity to the 3-m depth contour. The wave and seaNear-shore seawater-column measurements of excess radon (Rn-222) and water levels, Faga'alu Bay, Tutuila, American Samoa, August 2018
This data table includes in-situ near-shore seawater measurements of excess radon (Rn-222) and water levels collected in Faga'alu Bay, Tutuila, American Samoa.Modeled extreme total water levels along the U.S. west coast
This dataset contains information on the probabilities of storm-induced erosion (collision, inundation and overwash) for each 100-meter (m) section of the United States Pacific coast for return period storm scenarios. The analysis is based on a storm-impact scaling model that uses observations of beach morphology combined with sophisticated hydrodynamic models to predict how the coast will respondModel parameter input files to compare locations of coral reef restoration on different reef profiles to reduce coastal flooding
This dataset consists of physics-based XBeach Non-hydrostatic hydrodynamic models input files used to study how coral reef restoration affects waves and wave-driven water levels over coral reefs, and the resulting wave-driven runup on the adjacent shoreline. Coral reefs are effective natural coastal flood barriers that protect adjacent communities. Coral degradation compromises the coastal protect - Maps
Views of the Sea Floor in Northern Monterey Bay, California
A sonar survey that produced unprecedented high-resolution images of the sea floor in northern Monterey Bay was conducted in 2005 and 2006. The survey, performed over 14 days by the U.S. Geological Survey (USGS), consisted of 172 tracklines and over 300 million soundings and covered an area of 12.2 km2 (4.7 mi2). The goals of this survey were to collect high-resolution bathymetry (depth to the sea - Multimedia
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Physicochemical coastal groundwater dynamics between Kauhakō Crater lake and Kalaupapa settlement, Moloka‘i, Hawai‘i
Land-based sources of groundwater pollution can be a critical threat to coral reefs, and a better understanding of “ridge-to-reef” water movement is required to advance management and coral survival in the Anthropocene. In this study a more complete understanding of the geological, atmospheric, and oceanic drivers behind coastal groundwater exchange on the Kalaupapa peninsula, on Moloka‘i, Hawai‘iWave-driven hydrodynamic processes over fringing reefs with varying slopes, depths, and roughness: Implications for coastal protection
Wave breaking on the steep fore-reef slopes of shallow fringing reefs is effective at dissipating incident sea-swell waves prior to reaching reef shorelines. However, wave setup and free infragravity waves generated during the sea-swell breaking process are often the largest contributors to wave-driven water levels at the shoreline. Laboratory flume experiments and a multi-layer phase-resolving noPharmaceuticals and personal care products in passive samplers at seven coastal sites off West Maui, Hawaiʻi:
Passive membrane samplers—semipermeable membrane devices and polar organic chemical integrative samplers—were deployed for 22 continuous days at 7 sites along the West Maui, Hawaiʻi, coastline in February and March 2017 to assess organic contaminants at shallow coral reef ecosystems from diverse upstream inputs. The distribution of organic compounds observed at these coastal sites showed consideraA numerical study of geomorphic and oceanographic controls on wave-driven runup on fringing reefs with shore-normal channels
Many populated, tropical coastlines fronted by fringing coral reefs are exposed to wave-driven marine flooding that is exacerbated by sea-level rise. Most fringing coral reef are not alongshore uniform, but bisected by shore-normal channels; however, little is known about the influence of such channels on alongshore variations on runup and flooding of the adjacent coastline. We con-ducted a parameCharacterizing storm-induced coastal change hazards along the United States West Coast
Traditional methods to assess the probability of storm-induced erosion and flooding from extreme water levels have limited use along the U.S. West Coast where swell dominates erosion and storm surge is limited. This effort presents methodology to assess the probability of erosion and flooding for the U.S. West Coast from extreme total water levels (TWLs), but the approach is applicable to coastalHigh-resolution observations of submarine groundwater discharge reveal the fine spatial and temporal scales of nutrient exposure on a coral reef: Faga'alu, AS
Submarine groundwater discharge (SGD) can deliver substantial nutrient and contaminant loads to nearshore coral reefs. Correctly scaling SGD rates from a point source to a reef is generally a linear process involving simplified assumptions on the hydrogeology, bathymetry, and nearshore hydrodynamics that are essential to properly assess SGD scale and impact to individual coral heads. Here, we applHuman and ecosystem health in coastal systems
U.S. coastal economies and communities are facing an unprecedented and growing number of impacts to coastal ecosystems including beach and fishery closures, harmful algal blooms, loss of critical habitat, as well as shoreline damage. This paper synthesizes our present understanding of the dynamics of human and ecosystem health in coastal systems with a focus on the need to better understand nearshAction plan for restoration of coral reef coastal protection services: Case study example and workbook
This report was prepared by the U.S. Environmental Protection Agency (USEPA), Office of Research and Development, as part of the Air, Climate and Energy (ACE) research program, with support from Tetra Tech, Inc., and in collaboration with the National Oceanic and Atmospheric Administration, the U.S. Geological Survey, and The Nature Conservancy. The ACE research program provides scientific informaBiology: Integrating core to essential variables (Bio-ICE) task team teport for hard corals
The Interagency Ocean Observation Committee (IOOC) is chartered by the White House Office of Science and Technology Policy (OSTP) Subcommittee on Ocean Science and Technology (SOST). The purpose of the IOOC is to advise, assist, and make recommendations to the SOST on matters related to ocean observations via task teams such as the Biology - Integrating Core to Essential Variables (Bio-ICE) task tRigorously valuing the coastal hazard risks reduction provided by potential coral reef restoration in Florida and Puerto Rico
The restoration of coastal habitats, particularly coral reefs, can reduce risks by decreasing the exposure of coastal communities to flooding hazards. In the United States, the protective services provided by coral reefs were recently assessed in social and economic terms, with the annual protection provided by U.S. coral reefs off the coasts of the State of Florida and the Commonwealth of PuertoRigorously valuing the impact of projected coral reef degradation on coastal hazard risk in Florida
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. In the United States, the physical protective services provided by coral reefs were recently assessed, in social and economic terms, with the annual protection provided by U.S. coral reefs off the coast of the State of Florida estimated to be more thanRigorously valuing the impact of Hurricanes Irma and Maria on coastal hazard risks in Florida and Puerto Rico
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. In the United States, the physical protective services provided by coral reefs were recently assessed in social and economic terms, with the annual protection provided by U.S. coral reefs off the coasts of the State of Florida and the Commonwealth of PuNon-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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