<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><header style="color: rgb(51, 51, 51); font-family: arial, helvetica, 'ＭＳ Ｐゴシック', 'ＭＳ ゴシック', Osaka, 'MS PGothic', sans-serif; font-size: 14.495px; font-variant-ligatures: normal; orphans: 2; widows: 2; background-color: rgb(255, 255, 255);" class=""><div class="cleared top-links" style="margin: 0px; padding: 0px; zoom: 1;"><div class="comm-tool-box" style="margin: 0px; padding: 0px; position: relative; right: 0px; top: 0px;"><ul class="article-com-tools" style="margin: 0px 0px 20px; padding: 0px; float: right;"><li class="print" style="margin: 0px; padding: 4px 0px 2px 4px; list-style: none; float: right; display: block;"><a id="print-link" class="track" data-tooltip="Print" style="color: rgb(92, 121, 150); font-weight: bold; display: block; padding: 0px; text-indent: -2000px; direction: ltr; 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widows: 2; background-color: rgb(255, 255, 255);" class=""><dd class="doi" style="color: rgb(51, 51, 51); font-size: 14.495px; margin: 0px 0px 0px 4px; padding: 0px 3px 0px 10px; display: inline; background-image: url(applewebdata://791215EA-D139-4EF1-8864-AB3ABBD19917/view/images/bg_pipe.gif); background-position: 0px 0.4ex; background-repeat: no-repeat no-repeat;">doi:10.1038/ngeo2943</dd><div style="color: rgb(51, 51, 51); font-size: 14.495px;" class=""><br class=""></div><h1 class="article-heading" style="margin: 0px 0px 20px; padding: 0px; font-weight: normal; letter-spacing: -0.5px; line-height: 1.173;"><span style="font-size: 14px;" class="">Global aquifers dominated by fossil groundwaters but wells vulnerable to modern contamination</span></h1><ul class="authors citation-authors" style="margin: 0px 0px 10px; padding: 0px; font-weight: bold;"><span style="font-size: 14px;" class=""><li class="vcard c1" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-1" class="name" style="text-decoration: none;"><span class="fn">Scott Jasechko</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-2" class="name" style="text-decoration: none;"><span class="fn">Debra Perrone</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-3" class="name" style="text-decoration: none;"><span class="fn">Kevin M. Befus</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-4" class="name" style="text-decoration: none;"><span class="fn">M. Bayani Cardenas</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-5" class="name" style="text-decoration: none;"><span class="fn">Grant Ferguson</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-6" class="name" style="text-decoration: none;"><span class="fn">Tom Gleeson</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-7" class="name" style="text-decoration: none;"><span class="fn">Elco Luijendijk</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-8" class="name" style="text-decoration: none;"><span class="fn">Jeffrey J. McDonnell</span></a><span class="comma">,</span> </li><li class="vcard" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-9" class="name" style="text-decoration: none;"><span class="fn">Richard G. Taylor</span></a><span class="comma">,</span> </li><li class="vcard no-comma" style="margin: 0px; padding: 0px; list-style: none; display: inline;"><a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-10" class="name" style="text-decoration: none;"><span class="fn">Yoshihide Wada</span></a> </li><li class="vcard no-comma last-author" style="margin: 0px; padding: 0px; list-style: none; display: inline;">& <a href="http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2943.html#auth-11" class="name" style="text-decoration: none;"><span class="fn">James W. Kirchner</span></a></li></span></ul><ul id="author-links" class="cleared" style="color: rgb(51, 51, 51); font-size: 14.495px; margin: 0px 0px 20px; padding: 0px; zoom: 1;">Abstract</ul></header><section style="color: rgb(51, 51, 51); font-family: arial, helvetica, 'ＭＳ Ｐゴシック', 'ＭＳ ゴシック', Osaka, 'MS PGothic', sans-serif; font-size: 14.495px; font-variant-ligatures: normal; orphans: 2; widows: 2; background-color: rgb(255, 255, 255);" class=""><div class=" section first expanded" id="abstract" style="margin: 0px; padding: 0px; clear: both;"><div class="content " style="margin: 0px; padding: 0px; border-top: 1px solid rgb(231, 231, 231); zoom: 1; max-width: 628px;"><p style="margin: 0px 0px 20px; padding: 0px;" class="">The vulnerability of groundwater to contamination is closely related to its age. Groundwaters that infiltrated prior to the Holocene have been documented in many aquifers and are widely assumed to be unaffected by modern contamination. However, the global prevalence of these ‘fossil’ groundwaters and their vulnerability to modern-era pollutants remain unclear. Here we analyse groundwater carbon isotope data (<sup style="font-size: 12.3207px; line-height: 0;" class="">12</sup>C, <sup style="font-size: 12.3207px; line-height: 0;" class="">13</sup>C, <sup style="font-size: 12.3207px; line-height: 0;" class="">14</sup>C) from 6,455 wells around the globe. We show that fossil groundwaters comprise a large share (42–85%) of total aquifer storage in the upper 1<span class="mb" style="font-family: 'arial unicode ms', 'lucida grande', 'lucida sans unicode', sans-serif !important; font-size: inherit !important; line-height: inherit !important; display: inline !important; visibility: visible !important; background-image: none !important; background-color: transparent !important; padding: 0px !important; background-position: initial initial !important; background-repeat: initial initial !important;"> </span>km of the crust, and the majority of waters pumped from wells deeper than 250<span class="mb" style="font-family: 'arial unicode ms', 'lucida grande', 'lucida sans unicode', sans-serif !important; font-size: inherit !important; line-height: inherit !important; display: inline !important; visibility: visible !important; background-image: none !important; background-color: transparent !important; padding: 0px !important; background-position: initial initial !important; background-repeat: initial initial !important;"> </span>m. However, half of the wells in our study that are dominated by fossil groundwater also contain detectable levels of tritium, indicating the presence of much younger, decadal-age waters and suggesting that contemporary contaminants may be able to reach deep wells that tap fossil aquifers. We conclude that water quality risk should be considered along with sustainable use when managing fossil groundwater resources.</p></div></div></section><div class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">############################################################################<br class=""><br class="">“Climate has long been identified as a primary control on the geographic distribution of plants (Forman 1964, Box<br class="">1981). Therefore, plant species may be expected to exhibit marked redistributions in response to climate change. <br class="">Fossil pollen records from the Holocene period document such responses for a variety of plant species (e.g., <br class="">Delcourt and Delcourt 1988, Malanson 1993, Williams et al. 2004). In addition, species are expected to be <br class="">redistributed independently, forming new forest types with unique species combinations (Webb 1992, <br class="">Williams et al. 2004).”<br class=""><br class="">McKenney et al. Potential Impacts of Climate Change on the Distribution of North American Trees. Bioscience 2007</div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">“Forests are shaped by climate. Along with soils, aspect, inclination, and elevation, climate determines</div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""> what will grow where and how well. Changes in temperature and precipitation regimes therefore have</div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""> the potential to dramatically affect forests nationwide. “<br class=""> <br class="">Robert W. Malmsheimer, Patrick Heffernan, Steve Brink, Douglas Crandall, Fred Deneke, Christopher Galik, </div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Edmund Gee, John A. Helms, Nathan McClure, Michael Mortimer, Steve Ruddell, Matthew Smith, and John </div><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Stewart. Forest Management Solutions for Mitigating Climate Change in the United States. Journal of Forestry April/May 2008</div></div>
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