- Welcome, everyone, to Wednesday Nite @ the Lab. I'm Tom Zinnen, I work here at the UW-Madison Biotechnology Center. I also work for UW-Extension, Cooperative Extension. And on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite @ the Lab. We do this every Wednesday night, 50 times a year. Tonight, it's my pleasure to welcome back to Wednesday Nite @ the Lab, Ken Bradbury. He's with the Wisconsin Geological and Natural History Survey. He was born in Richmond, Indiana, and graduated from Richmond Senior High School. And then he went to Ohio Wesleyan University and majored in geology. Got a master's degree at Indiana University in geology. And he came here to UW-Madison to get his PhD and he went way, way out there and got a PhD in hydrogeology. (audience chuckling) Then he went directly to the Wisconsin Geological and Natural History Survey, that was in 1982. He's been there 36 years. And since 2015, he has been the director there. And in that role, he also serves as Wisconsin State Geologist, which is a role that Thomas Chamberlin and Charles Van Hise I believe also held. And they became presidents of the university. (audience laughing) Tonight, Ken gets to talk with us about groundwater, wetlands, and geology, the invisible links. And now while he's saying they're invisible, I think we're starting to see more and more that they're pretty visible. And the question is what do we get to do about that? So please join me in welcoming Ken back to Wednesday Nite @ the Lab. - Thank you, Ken. - Thank you, Tom. (audience applauding) Well, thank you, Tom, and thanks, everybody, for coming tonight. So this is a reprise of a talk that I put together for the Wisconsin Wetlands Association for their conference about a year ago. The point I wanna make is that we all like wetlands and wetlands are pretty prolific in Wisconsin and the Upper Midwest. But groundwater, which as a hydrogeologist is my specialty, is pretty important for wetlands, and many people don't understand all the links. And the more we think about wetlands, we really have to understand the groundwater system around them. So this talks a bit about wetlands and a bit about groundwater and how they act together. There's a lot of wetlands in the Upper Midwest, lot of wetlands in the United States. On this map, all the green areas are wetlands. And you can see that in the Upper Midwest, we have our share of wetlands, more than many other places in the country. This hashed area are the pothole prairies of Minnesota and North Dakota, where there are many, many, many small wetlands. And so we have a lot of wetlands in the Upper Midwest. And these are all connected to groundwater in one way or another. Why? Why do we have all these wetlands? And I think it's interesting to think about why we have them. First of all, where do wetlands occur? They occur in-- The main areas in the United states are glaciated terrain where we are now, also in coastal terrain like the coastal plain here and in Florida and the Southeast, and then along rivers like the Mississippi or the Wisconsin, so those are places wetlands occur. But it's interesting to me that if you look at the pattern of wetlands in the Upper Midwest, kind of draw a line like this, you realize that they really follow our glaciated areas. So here's a map of the glaciated region of the Upper Midwest. So this is the area covered by glaciers during the Pleistocene. And you can see that that fairly well matches the extent of major wetlands in the Upper Midwest. Why is that? Well, for one thing it's a fairly leveled or lower leaf topography. We don't have a lot of mountain ranges unfortunately. And it's a fairly young landscape and it's often kind of hummocky and pitted so there are a lot of places for water to collect. And in general, we have a humid climate and it's not too far to groundwater in most of these places, so all these things work together to give us a lot of wetlands here. I me