measurements

NASA/JPLThick or thin ice shell on Jupiter’s moon Europa? Scientists are all but certain that Europa has an ocean underneath its surface ice, but do not know how thick this ice might be.Jupiter’s moon Europa is just as far away as ever, but new research is bringing scientists closer to being able to explore its tantalizing ice-covered ocean and determine its potential for harboring life. William B. McKinnon, professor of earth and planetary sciences at Washington University in St. Louis, is discussing some of these recent findings and new opportunities for exploring Europa in a news briefing on Thursday, Dec. 13, 2007, at the meeting of the American Geophysical Union in San Francisco.

Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences, has analyzed data from the Lewis and Clark expedition and says it shows that the Missouri River today is but a shadow of what it was two hundred years ago, narrower and more prone to serious flooding.A geologist at Washington University in St. Louis and his collaborator at Oxford University have interpreted data that Lewis and Clark collected during their famous expedition and found that the Missouri River has markedly narrowed and its water levels have become more variable over the past two hundred years. This narrowing, or channeling, created by wing dikes and levees constructed mainly in the 20th century, has put the Missouri River at an increased risk of more damaging floods, the authors say. They blame the fact that the river cannot spread out as it did naturally at the turn of the 19th century, thus forcing water levels higher. More…