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Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii

September 20, 2016

Study region

The study region encompasses the nearshore, coastal waters off west Maui, Hawaii. Here abundant groundwater—that carries with it a strong land-based fingerprint—discharges into the coastal waters and over a coral reef.

Study focus

Coastal groundwater discharge is a ubiquitous hydrologic feature that has been shown to impact nearshore ecosystems and material budgets. A unique combined geochemical tracer and oceanographic time-series study addressed rates and oceanic forcings of submarine groundwater discharge at a submarine spring site off west Maui, Hawaii.

New hydrological insights for the region

Estimates of submarine groundwater discharge were derived for a primary vent site and surrounding coastal waters off west Maui, Hawaii using an excess 222Rn (t1/2 = 3.8 d) mass balance model. Such estimates were complemented with a novel thoron (220Rn,t1/2 = 56 s) groundwater discharge tracer application, as well as oceanographic time series and thermal infrared imagery analyses. In combination, this suite of techniques provides new insight into the connectivity of the coastal aquifer with the near-shore ocean and examines the physical drivers of submarine groundwater discharge. Lastly, submarine groundwater discharge derived constituent concentrations were tabulated and compared to surrounding seawater concentrations. Such work has implications for the management of coastal aquifers and downstream nearshore ecosystems that respond to sustained constituent loadings via this submarine route.

Citation Information

Publication Year 2016
Title Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii
DOI 10.1016/j.ejrh.2015.12.056
Authors Peter W. Swarzenski, H. Dulai, K.D. Kroeger, C.G. Smith, N. Dimova, C. D. Storlazzi, N.G. Prouty, S. B. Gingerich, C. R. Glenn
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Hydrology: Regional Studies
Series Number
Index ID 70176523
Record Source USGS Publications Warehouse
USGS Organization Pacific Coastal and Marine Science Center