Cleantech Market Intelligence
New Discoveries Change Notions of Fresh Water
Two new water discoveries have the potential to significantly alter our understanding and future use of this increasingly scarce resource. One involves semi-fresh water located under the ocean, and the other is a find below the frozen surface of Greenland.
First, scientists have determined that an estimated half million cubic kilometers of low-salinity water (low enough to be turned into potable water) are trapped beneath the seabed on continental shelves around the world, according to a new study published in the international scientific journal Nature. The amount of potentially useful water is staggering: a hundred times greater than the amount extracted from the earth’s sub-surface since 1900, according to Dr. Vincent Post, the study’s lead author and a professor in the School of the Environment at Flinders University, which oversees Australia’s National Centre for Groundwater Research and Training (NCGRT).
This offshore groundwater has been found off Australia, North America, South Africa, and China. It could be utilized to supplement existing water sources for coastal cities and surrounding areas, and could potentially sustain some regions for decades. There are two methods of extracting this water, according to Dr. Post: build an offshore drilling platform and pipe the water to shore, or drill from the mainland or from islands near the aquifers. Previously, scientists thought this water only existed under rare and special conditions.
Under the Ice
The second discovery was made in Greenland, where researchers drilling through an ice core found something very surprising about 30 feet down: a giant aquifer estimated to be 27,000 square miles, larger than the state of West Virginia. Details of the discovery were published recently in Nature Geoscience.
The Greenland aquifer is not considered as a water source for human activity; however, the environmental significance of this finding could be very important. Scientists theorize the aquifer connects to a network of crevasses and streams that flow to ice sheets and helps lubricate the flowing glaciers. They also suspect that the aquifer acts like a giant storage area, which could burst at some point, sending a large volume of water out of the ice sheet. It may be a little of both phenomena taking place, according to Richard Forster, a glaciologist at the University of Utah whose students were among those drilling the core. Forster has applied for more research funding to study the huge aquifer and how it might affect future ocean levels. Given the amount of water – perhaps more than 100 billion tons – it could be enough to raise global sea levels by 0.4 millimeters, if it all flowed into the sea at once. The melting of Greenland’s ice sheet adds about 0.7 millimeters of sea-level rise each year, under current conditions, so a 0.4 millimeter increase would be significant.
These revelations come on the heels of the earlier discovery this year of aquifers in Africa, where large underground reservoirs could help ease drought conditions in North Kenya, as noted in a previous blog.
At this point the implications of these two latest discoveries are not fully known, and neither offers a panacea for the many issues surrounding water. One could be a big boost for coastal areas in need of additional water sources, and the other could help deepen our understanding of fluctuating ocean levels. Both are worthy of further study to determine what course of action, if any, makes sense. Clearly, the aquifers under the sea could pay dividends by helping to reduce the effects of drought or water shortages on land. But it will require careful drilling techniques and, among other things, the application of smart distribution technologies (some of which are described in Navigant Research’s report, Smart Water Networks). As Dr. Post warns, “These water reserves [under the sea] are non-renewable,” and “we should use them carefully – once gone, they won’t be replenished until the sea level drops again, which is not likely to happen for a very long time.”