Lubricating meltwater that makes its way from the surface down to where a glacier meets bedrock turns out to be only a minor reason why Greenland’s outlet glaciers accelerated their race to the sea 50 to 100 percent in the 1990s and early 2000s, scientists say. Their work also shows that surface meltwater is reaching bedrock farther inland under the Greenland Ice Sheet, something scientists had speculated was happening but had little evidence.