Program and Agenda

Abstract

SUBMARINE GROUNDWATER DISCHARGE IN A STREAM-DOMINATED EMBAYMENT: KAHANA BAY, O`AHU, HAWAI`I

Located on the northeastern shore of O`ahu, Hawai`i, Kahana Valley is one of the island’s wettest watersheds. It has a continuously flowing stream, which introduces some challenges when conducting a submarine groundwater discharge (SGD) study. This study utilized a combination of established SGD research techniques, including high-resolution airborne thermal infrared (TIR) remote sensing and in-situ surveys for groundwater tracers (e.g. salinity, temperature, and 222Rn activities). This combination of techniques provided a quantitative understanding of the regional-scale and intra-daily variability of SGD in Kahana Bay. The total SGD flux was calculated to be 62,736 m3/day, approximately 63% of which was derived from a traditional Hawaiian fishpond on the bay’s eastern shore. This fishpond also had the highest nutrient concentrations in the bay. Remarkably, the SGD-derived nutrient fluxes to the bay were calculated be greater than or equal to those from Kahana Stream, ranging from ratios of 5:1 for TDP, 4:1 for TDN, and 1:1 for silica. Submarine groundwater discharge, therefore, has a significant influence on the bay’s geochemical budgets.

ePoster:

Authors

Mayfield, K. K., University of California Santa Cruz, USA, kkmayfie@ucsc.edu

Dulaiova, H., University of Hawaii at Manoa, USA, hdulaiov@hawaii.edu

Glenn, C. R., University of Hawaii at Manoa, USA, glenn@soest.hawaii.edu

Kelly, J. L., Georgia Southern University, USA, jlkelly@georgiasouthern.edu

Details

Poster presentation

Session #:060
Date: 2/25/2014
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 1080