Mean annual temperature in New Zealand during the last glacial maximum derived from dissolved noble gases in groundwater

TitleMean annual temperature in New Zealand during the last glacial maximum derived from dissolved noble gases in groundwater
Publication TypeJournal Article
Year of Publication2015
AuthorsSeltzer A.M, Stute M., Morgenstern U., Stewart M.K, Schaefer J.M
JournalEarth and Planetary Science Letters
Volume431
Pagination206-216
Date Published2015/12
Type of ArticleArticle
ISBN Number0012-821X
Accession NumberWOS:000363828600020
Keywordsalps; climate-change; Groundwater; hawkes bay; lake; last glacial maximum; LGM; New Zealand; noble gas; northern new-zealand; paleotemperature; paleotemperature record; pollen record; poukawa; sea-surface temperatures; southern; southwest pacific; water
Abstract

This study presents a reconstruction of mean annual surface temperature in New Zealand over the last glacial period using groundwater noble gas paleothermometry. Low resolution C-14-derived mean recharge ages of groundwater from the Deep Moutere, Deep Wairau, and Taranaki aquifers range from roughly 41,500 yr to present, including the last glacial maximum (LGM). Modeled noble gas temperatures of probable glacial-age samples range from roughly 3.7-6.2 degrees C cooler than present. We present an error-weighted mean cooling of 4.6 +/- 0.5 degrees C relative to present during last glacial period. The screened depth intervals of some wells sampled in this study allow for a degree of mixing during extraction between groundwater layers of different recharge age. Mixing with modern groundwater may slightly elevate the noble gas temperatures (NGTs) of glacial-age samples while making them appear substantially younger. Given the uncertainty in dating, we cannot rule out a larger LGM temperature depression of up to similar to 6 degrees C. The similar to 4.6 degrees C cooling estimate agrees with a number of terrestrial paleoclimate reconstructions near the study area as well as the majority of nearby paleoceanographic temperature studies. (C) 2015 Elsevier B.V. All rights reserved.

DOI10.1016/j.epsl.2015.09.032
Short TitleEarth Planet. Sci. Lett.
Student Publication: 
Yes
Student: 
Research Topics: 
sharknado