A giant reservoir of "secret" fresh water off the East Coast that could potentially supply a city the size of New York City for 800 years may have formed during the last ice age, when the region was covered in glaciers, researchers say. Preliminary analyses suggest the reservoir, which sits beneath the seafloor and appears to stretch from offshore New Jersey as far north as Maine, was locked in place under frigid conditions around 20,000 years ago, hinting that it formed in the last glacial period due, partly, to thick ice sheets. Last summer, researchers went on an expedition to...