Please use this identifier to cite or link to this item:
Title: Responses of atoll freshwater lenses to storm-surge overwash in the Northern Cook Islands
Authors: Terry, J.P. 
Falkland, A.C.
Keywords: Freshwater lens
Island hydrology
Salt-water/fresh-water relations
South Pacific
Issue Date: May-2010
Source: Terry, J.P., Falkland, A.C. (2010-05). Responses of atoll freshwater lenses to storm-surge overwash in the Northern Cook Islands. Hydrogeology Journal 18 (3) : 749-759. ScholarBank@NUS Repository.
Abstract: A category 5 tropical cyclone swept a storm surge across remote Pukapuka Atoll in the Northern Cook Islands (South Pacific Ocean) in late February 2005. Groundwater salinity (specific conductance) observations are reported for the 2-year post-storm period, with the aim of investigating the effects of saltwater intrusion on thin freshwater lenses within the atoll islets. This is the first article to present field observations of such an event. Specific conductance at shallow depths increased dramatically from potable conditions (approximately 1,000 μS/cm) to brackish levels unsuitable for drinking (up to 10,000 μS/cm) shortly after the cyclone. Subsequently, the freshwater lenses required 11 months to recover. Within the thickest aquifer, a well-defined saline plume formed at 6 m depth, sandwiching a freshwater layer beneath it and the base of the lens. Plume dispersal proceeded only gradually, owing to its formation at the start of the SW Pacific regional dry season and the low tidal range on Pukapuka. Consequently, the remnant of the plume was still present 26 months after the saltwater incursion. An important finding was that the freshwater horizon preserved at depth maintained salinity levels below 1,800 μS/cm (i.e. within usable limits) for at least 5 months after surface overwash. © 2009 Springer-Verlag.
Source Title: Hydrogeology Journal
ISSN: 14312174
DOI: 10.1007/s10040-009-0544-x
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Feb 28, 2018


checked on Mar 5, 2018

Page view(s)

checked on Feb 25, 2018

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.