Who said geology isn't awesome? Catch "Making North America: Human" Wed. 11/18 at 9/8c on PBS.
  1. Kansas and much of the Midwest were once submerged under a massive inland sea.
    The Western Interior Seaway (also called the Cretaceous Seaway) was a huge inland sea that split North America into two halves during much of the Cretaceous Period. This shallow sea was filled with diverse marine life, including mosasaurs nearly 60 feet long and the terrifying, 18-foot-long fish dubbed Xiphactinus.
  2. Once Panama joined North and South America together, it changed the circulation and climate of our planet.
    Before the Isthmus of Panama was formed, Pacific waters flowed into the Atlantic and vice versa, balancing the two oceans’ salinity. But once the seas were separated by Panama, dramatic changes in ocean circulation occurred—the Atlantic got saltier and the Pacific got fresher. As a result, the Gulf Stream in the Atlantic intensified and—according to one theory—transported moisture to the North Atlantic region, contributing to the formation of ice and glaciers.
  3. A monstrous chamber of magma is parked under Yellowstone. And if history is any indication, when it blows, the results will be devastating.
    There’s enough partially molten rock under Yellowstone to fill 13 Grand Canyons.
  4. Camels originated in North America 40 to 50 million years ago.
    It was in the western part of the continent that camels underwent most of their evolution as a species. Later they migrated into Asia by crossing the Bering land bridge.
  5. Monkeys and other primates used to live in North America because it was tropical.
    Scientists believe that as many as 43 million years ago, early primates crossed the Atlantic from Africa on some sort of vegetation raft. That’s right—they were little monkey sailors.
  6. New York City used to be part of a mountain range 10 times taller than any skyscraper.
    These mountains were composed of rock deposited at the bottom of the ocean 300 million years prior. Eventually, they were eroded away—leaving strong bedrock that made construction on the island of Manhattan particularly easy.
  7. The Rockies are the third generation of mountains in that region.
    The repeated subduction of the Pacific oceanic plate beneath the North American continental plate has caused numerous upheavals.
  8. Gooseberry Falls in Minnesota was once the site of a huge volcanic eruption that lasted 20 million years.
    1.1 billion years ago, lava poured out of a massive rift that formed in North America’s crust. Over time, it cooled to form volcanic bedrock known as basalt, which persists beneath Gooseberry Falls to this day.
  9. One of "Making North America" host Kirk Johnson's favorite books is "Annals of the Former World" by John McPhee, which won the 1999 Pulitzer Prize for General Non-Fiction.
    We're reading this book as part of the #NOVAreads Virtual Book Club. It's long, but we'll be breaking it down for you. More info on our Goodreads page! (Search "NOVAreads" on Goodreads.)