Over the course of the last 2.5 million years, catastrophic glacial floods remade the landscape of eastern Washington, carving out the distinctive landforms of the channeled scablands.

These floods carried icebergs, and the icebergs contained rocks of all sizes. When these icebergs became stranded, they melted and these rocks were left behind. Unusual boulders scattered across the landscape are evidence of this process.

What is the spatial distribution of these boulders? What are the rock types?

If we could answer these questions, we would learn a lot about these ancient catastrophic floods.

Then, advanced geochemical techniques could take study of the flood-rafted boulders to the next level. 10Be and 26Al measurements can answer how long the boulders have been sitting around at their present location, and other measurements like 40Ar/39Ar, and U/Pb can determine the age of crystallization and thus provide specific information about the source regions for the different boulders.

Similar megaflood processes are threatening to play a major role in the collapse of major continental ice sheets in the modern era of anthropogenic global warming. Understanding glacial flooding is one of the keys to predicting the pace of sea level rise. less ↑