Reef Hydrodynamics and Sediment Processes
Science Center Objects
The overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Tripod deployed on the reef flat off Jurabi, Ningaloo World Heritage Site, Western Australia, with instrumentation designed to measure tides, waves, currents, and sediment being transported across the reef. Photo credit: Curt Storlazzi, USGS
The Problem
Over the past decade, we have primarily focused on fine-grained terrestrial sediment dynamics on reefs, due to its role as the greatest stressor to high-island fringing reefs throughout the U.S. and U.S.-Affiliated Pacific Islands, such as Hawaii, Guam, American Samoa, and large Office of Insular Affairs islands. However, recently we have expanded our focus to include carbonate sediment, as approximately 80-90% of coral reefs are constructed of lithified carbonate sediment (carbonate sand and rubble adhered together by calcareous algae, not intact coral growth). Because this carbonate sediment is a critical component of beach sediment supply, it represents an important resource for recreation and coastal storm protection. Although a key factor in the vertical growth of reefs and their ability to keep up with rising sea levels, carbonate reef sediment dynamics are poorly understood and this knowledge gap was recently determined to be a critical area of research for investigating climate-change impacts to coral reef-lined coasts.
Numerically simulated Lagrangian coral larval dispersal patterns from the Olowalu reef on west Maui, Hawaiʻi, for four different coral larval spawning events. Such modeling demonstrates the potential for a given reef to seed different islands and their respective reefs over relatively short timescales.
Our Approach
The overall objective of this research is to better understand how hydrodynamics and sediment processes influence the development of coral reefs and their adjacent shorelines. Specifically, we are:
- Evaluating the role of coral-reef morphology on waves and wave-driven water levels over coral reefs and their resulting influence on coastal flooding.
- Elucidating the patterns of flow over coral reefs that result from different forcing mechanisms such as waves, currents, surface tides, internal tides, and subtidal motions.
- Determining the sources, pathways, and retention times of sediment, nutrients, and contaminants over complex coral reef morphologies.
- Identifying the circulation pathways that link separate reefs through larval or pollutant transport, and determine the spatial and temporal scales at which these pathways occur.
- Evaluating how these processes and linkages will be affected by projected changes in climate such as sea-level rise and changes in the frequency and intensity of storms.
The overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Caption for large photo at top of page: Photograph of large (6-meter-/20-foot-high) waves resuspending terrestrial flood sediment on the coral reefs off Puʻukoholā Heiau National Historic Site and Kawaihae Harbor, Hawaiʻi.
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.
Land-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018
The effects of runoff from land on nearshore ecosystems, including coral reef communities, are influenced by both sediment supply and removal by coastal processes. Integrated studies across the land-sea interface describing sources and transport of terrestrial sediment and its nearshore fate allow reef protection initiatives to target...
Takesue, Renee K.; Sherman, Clark E; Reyes, Aaron O.; Cheriton, Olivia; Ramirez, Natalia I.; Viqueira Ríos, Roberto; Storlazzi, Curt Wave-driven flood-forecasting on reef-lined coasts early warning system (WaveFoRCE)
Increasing the resilience of coastal communities while decreasing the risk to them are key to the continued inhabitance and sustainability of these areas. Low-lying coral reef-lined islands are experiencing storm wave-driven flood events that currently strike with little to no warning. These events are occurring more frequently and with increasing...
Skirving, William; Storlazzi, Curt; Smail, Emily A The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system.
Coral reefs generate substantial volumes of carbonate sediment, which is redistributed throughout the reef‐lagoon system. However, there is little understanding of the specific processes that transport this sediment produced on the outer portions of coral reefs throughout a reef‐lagoon system. Furthermore, the separate contributions of currents,...
Pomeroy, Andrew; Storlazzi, Curt; Rosenberger, Kurt J.; Lowe, Ryan; Hansen, Jeff; Buckley, Mark L.
Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014
Coral reefs worldwide are experiencing rapid degradation in response to climate and land-use change, namely effects of warming sea-surface temperatures, contaminant runoff, and overfishing. Extensive coral bleaching caused by the steady rise of sea-surface temperatures is projected to increase, but our understanding and ability to predict where...
Grossman, Eric E.; Marrack, Lisa; vanArendonk, Nathan R. Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
Coral reefs are an important source of sediment for reef-lined coasts by helping to maintain beaches while also providing protection in the form of wave energy dissipation. Understanding the mechanisms by which sediment is delivered to the coast as well as better constraining the total volumes generated are critical for projecting future coastal...
Rosenberger, Kurt J.; Storlazzi, Curt D.; Cheriton, Olivia; Pomeroy, Andrew; Hansen, Jeff E.; Lowe, Ryan; Buckley, Mark In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
The character and energetics of infragravity (IG, 25 s < period < 250 s) and very-low frequency (VLF, period > 250 s) waves over coral reef flats can enhance shoreline erosion or accretion, and also govern extreme shoreline events such as runup, overwash, and flooding on coral reef-lined coasts. Here we use in situ wave measurements...
Cheriton, Olivia; Storlazzi, Curt D.; Rosenberger, Kurt J. Pulse sediment event does not impact the metabolism of a mixed coral reef community
Sedimentation can bury corals, cause physical abrasion, and alter both spectral intensity and quality; however, few studies have quantified the effects of sedimentation on coral reef metabolism in the context of episodic sedimentation events. Here, we present the first study to measure coral community metabolism - calcification and photosynthesis...
Keisha Bahr; Ku'ulei Rodgers; Paul Jokiel; Prouty, Nancy G.; Storlazzi, Curt D. Integrating structure from motion, numerical modelling and field measurements to understand carbonate sediment transport in coral reef canopies
Reef canopies are complex and extremely variable across a range of spatial scales. This variability affects the velocity above as well as within the canopy, and directly impacts the transport of sediment along the bed as well as suspended in the water column. How a canopy affects the transport of sediment is important to understand and predict...
Pomeroy, Andrew; Storlazzi, Curt D.; Rosenberger, Kurt J.; Hatcher, Gerry; Warrick, Jonathan The influence of sea level on incident and infragravity wave-driven sediment dynamics across a fringing coral reef
Coral reefs generate significant volumes of carbonate sediment that becomes the primary source of beach material along many low-latitude shorelines that protect hundreds of millions of people globally. Despite this fact, there is little understanding of the specific processes that transport the carbonate sediment produced on the outer portions of...
Storlazzi, Curt D.; Cheriton, Olivia; Rosenberger, Kurt J.; Pomeroy, Andrew; Lowe, Ryan J. Controls on sediment transport over coral reefs off southwest Puerto Rico: Seasonal patterns and Hurricane Maria
Guánica Bay in southwest Puerto Rico is highly turbid and has some of the highest PCB concentrations in the USA. To investigate how and to what extent the bay waters influence coral reef ecosystem health along the coastline, 6 months of hydrodynamic data were collected at 8 sites on the insular shelf. Bed shear stresses were primarily driven by...
Cheriton, Olivia; Storlazzi, Curt D.; Rosenberger, Kurt J.; Sherman, Clark Assessing morphologic controls on atoll island alongshore sediment transport gradients due to future sea-level rise
Atoll islands’ alongshore sediment transport gradients depend on how island and reef morphology affect incident wave energy. It is unclear, though, how potential atoll morphologic configurations influence shoreline erosion and/or accretion patterns, and how these relationships will respond to future sea-level rise (SLR). Schematic atoll models...
Shope, James B.; Storlazzi, Curt D. Spatial and temporal variability in ripple formation and migration across a coral reef flat and lagoon
The transport of carbonate sediment across reefs to the shoreline is of great interest to the research community and coastal managers alike. This sediment is generated by the breakdown of reef skeletal structure and a critical source for beach nourishment that provides a buffer to coastal flooding as sea levels rise. Understanding the physical...
Rosenberger, Kurt J.; Storlazzi, Curt D.; Pomeroy, Andrew; Cheriton, Olivia; Lowe, Ryan J.; Hansen, Jeff-
Date published: March 26, 2021Cross-reef wave and water level data from coral reef environments
Direct field observations of wave dynamics across coral reefs and the resulting water levels are limited. Here we provide direct in situ measurements of waves and water levels across a number of coral reefs, extending from the fore reef, across the reef crest, and to the shoreline. These measurements are provided to help better understand the evolution of waves across coral reefs and...
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Date published: January 27, 2021Jurabi, Exmouth, Western Australia, 2016 Coral Reef Circulation and Sediment Dynamics Experiment
Carbonate reefs are a major source of sediment for coastlines in much of the tropical regions of the world, contributing to significant shoreline accretion and beach nourishment. A collaborative experiment between USGS and University of Western Australia was conducted to investigate determine the primary oceanographic processes responsible for cross-reef sediment transport. Data will be added...
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Date published: January 1, 2019Time-series oceanographic data collected from reef flat and lagoon sediment dynamics packages in 2016 off Jurabi Point, Ningaloo Reef, Western Australia
Time series data of water surface elevation, wave height, water column currents and temperature, and suspended sediment were acquired for 6 weeks on a coral reef off Jurabi Point, Ningaloo Coast UNESCO World Heritage site in Western Australia in support of a study on the circulation and sediment transport patterns of these reefs.