Jodi N. Harney






































Welcome to my study area...
Kailua Bay, Oahu, Hawaii


Multispectral and 3D imagery courtesy Ebitari Isoun. Click to see a full-size version.

Jodi N. Harney
jharney@soest.hawaii.edu
Ph.D. Student, Coastal Geology Group
Dept. of Geology & Geophysics, University of Hawaii


Kailua Bay is located on the northeast (windward) coast of Oahu in the Hawaiian Archipelago. The embayed shoreline lies between pronounced headlands that define the geographic limits of the system. The bay experiences an annual range of wind, wave, and water quality conditions. Trade winds blow onshore at 10-15 kts 90% of the summer, generating waves 1-3 m in height with periods of 6-12 s. During the winter, trade winds blow at variable speeds 50-80% of the season, and storms in the North Pacific deliver large swells (4 m, 10-20 s) that may refract into the bay. Observational data sets describing conditions are available from various sources (principally NOS buoys and weather stations) extending through recent decades.




See Ebitari Isoun's web pages for information on this image, part of her master's thesis.
Benthic habitats are illustrated in the georeferenced, orthographically-rectified, digital mosaic of airborne multi-spectral data shown at left. Dark areas are consolidated substrate, living coral, and algae; light areas are typically sandy regions. The sandy shoreline grades seaward to a shallow (<5 m depth), fossil limestone surface with a veneer of sand (hardgrounds). A large sand field in the central nearshore region marks the onshore extent of the paleo-channel and contrasts the generally sand-poor regions directly north and south.




Photo courtesy of Eric Grossman.
Substrates of the nearshore region and reef platform include sand, rubble, fossil limestone outcrops, mounds of the reef-building coral Porites lobata (like the one shown at left), meadows of the calcareous alga Halimeda, and fleshy algae such as Sargassum.




Porites compressa on the fore-reef slope.
A broad fringing reef dominates the shoreface (defined as the entire littoral cell from shoreline to 5 km offshore). The reef lies in 5-20 m water depth and is more than 4 square km in area. The landward portion of the reef platform lies in 5-8 m water depth and is composed largely of fossil reef outcrops with 25-50% living coral cover. The seaward reef platform extends several km offshore in depths of 15-20 m as spur and groove topography with 50-100% living coral cover. Along the reef margin 3 km offshore, the fore-reef slopes steeply seaward (in some places as talus and elsewhere as living coral cover) to abut a sand field at -25 m. The scleractinian coral genera Porites, Montipora,and Pocilloporacharacterize the reef platform, and their distribution, abundance, and morphology varies with depth and hydrodynamic energy.

Coralline (red) algae are also prolific inhabitants of the benthic community at all depths. Branching Porolithon gardineriis most abundant in shallow waters, while encrusting Porolithon onkodesand other species are found in all depths and habitats.




What's the difference?


Both of these images are of the Kailua shoreface. The image on the left is an NOS aerial photo. The image on the right is the a georeferenced mosaic of multispectral reflectance data. The data was collected at a resolution of 1 m per pixel, providing us a great basemap of submarine features. This is not only an "image," but the data can be used to formulate models of bathymetry and bottom-type. For more information, check out the master's research of a fellow Coastal Geology Group student, Ebitari Isoun.


Sediment budget

My current research involves constructing a sediment budget or "model" of the production, storage, flux, and loss of carbonate sediment in Kailua Bay during the last 5000 years. Please visit my new sediment budget page.







   
Go to my MAIN page Go to our COASTAL pages